Dissertations / Theses: 'Occupational exposure'

1

Alwis, Kuruppuge Udeni. "Occupational Exposure to Wood Dust." Thesis, The University of Sydney, 1998. http://hdl.handle.net/2123/392.

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ABSTRACT Occupational exposure to wood dust and biohazards associated with wood dust (endotoxins, (1->3)-b-D-glucans, Gram (-)ve bacteria and fungi), their correlation to respiratory function, and symptoms among woodworkers have been investigated in the present study. Wood dust, endotoxins, and allergenic fungi are the main hazards found in woodworking environments. Relatively very few studies have been done on wood dust exposure. The present study was designed to comprehensively investigate the health effects of wood dust exposure, and in particular provide new information regarding: Exposure to (1->3)-b-D-glucans in an occupational environment; Levels of exposure to wood dust and biohazards associated with wood dust in different woodworking environments; Correlations among personal exposures, especially correlations between (1->3)-b-D-glucans and fungi exposures, and endotoxins and Gram (-)ve bacteria exposures; Effects of personal exposure to biohazards on lung function; Effects of personal exposure to biohazards on work-related symptoms; and Determinants of inhalable exposures (provide which factors in the environment influence the personal inhalable exposures). Workers at four different woodworking processes; two logging sites, four sawmills, one major woodchipping operation and five joineries situated in the state of New South Wales in Australia were studied for personal exposure to inhalable dust (n=182) and respirable dust (n=81), fungi (n=120), Gram (-)ve bacteria (n=120), inhalable endotoxin (n=160), respirable endotoxin (n=79), inhalable (1->3)-b-D-glucan (n=105), and respirable (1->3)-b-D-glucan (n=62). The workers (n=168) were also tested for lung function. A questionnaire study (n=195) was carried out to determine the prevalence of work-related symptoms. The geometric mean inhalable exposure at logging sites was 0.56 mg/m3 (n=7), sawmills 1.59 mg/m3 (n=93), the woodchipping mill 1.86 mg/m3 (n=9) and joineries 3.68 mg/m3 (n=66). Overall, sixty two percent of the exposures exceeded the current standards. Among joineries, 95% of the hardwood exposures and 35% of the softwood exposures were above the relevant standards. Compared with green mills, the percentage of samples, which exceeded the hardwood standard was high for dry mills (70% in dry mills, 50% in green mills). The respirable dust exposures were high at the joineries compared with the other worksites. Exposure levels to fungi at logging sites and sawmills were in the range 103-104 cfu/m3, woodchipping 103-105 cfu/m3 and joineries 102-104 cfu/m3. The predominant fungi found at sawmills were Penicillium spp. High exposure levels of Aureobasidium pullulans were also found at two sawmills. At the woodchipping mill the predominant species were Aspergillus fumigatus, Penicillium spp., and Paecilomyces spp. The sawmills, which employed kiln drying processes, had lower exposure levels of fungi compared with the green mills. Those workplaces which had efficient dust control systems showed less exposure to fungi and bacteria. Although mean endotoxin levels were lower than the suggested threshold value of 20 ng/m3, some personal exposures at sawmills and joineries exceeded the threshold limit value. The mean inhalable (1->3)-b-D-glucan level at the woodchipping mill was 2.32 ng/m3, at sawmills 1.37 ng/m3, at logging sites 2.02 ng/m3, and at joineries 0.43 ng/m3. For the respirable size fraction, mean endotoxin and mean (1->3)-b-D-glucan concentrations were much lower, being similar to observed dust concentrations. Significant correlations were found between mean inhalable endotoxin and Gram (-)ve bacteria levels (p<0.0001), and mean airborne inhalable (1->3)-b-D-glucan and fungi levels (p=0.0003). The correlations between mean respirable endotoxin levels vs Gram (-)ve bacteria exposure levels (p=0.005), and respirable (1->3)-b-D-glucan exposure levels vs total fungi levels (p=0.005) were also significant. Significant correlations were found between lung function and personal exposures. Multivariate analyses showed that the effect of all the personal exposures on cross-shift decrements in lung function was more prominent among sawmill and chip mill workers compared with joinery workers. Woodworkers had markedly high prevalence of cough, phlegm, chronic bronchitis, frequent headaches, throat and eye irritations, and nasal symptoms compared with controls. Among the woodworkers, smokers had a high prevalence of chronic bronchitis (20%) compared with non-smokers (10%). Some workers also reported a variety of allergy problems due to exposure to various types of wood dust. Both joinery workers and sawmill and chip mill workers revealed significant correlations between work-related symptoms and personal exposures. Chronic bronchitis was significantly correlated with personal exposure to wood dust, endotoxin, (1->3)-b-D-glucan, fungi, and Gram (-)ve bacteria among joinery workers. Whereas among sawmill workers chronic bronchitis was significantly correlated with personal exposure to endotoxin, (1->3)-b-D-glucan, and fungi. Woodworkers showed significant positive correlations between percentage cross-shift change (decrease) in lung function and respiratory symptoms. Significant inverse correlations were also found among percentage predicted lung function and respiratory symptoms. The elevated inhalable dust exposures observed in this study can be explained by a combination of factors, including: lack of awareness of potential health effects of wood dust exposure among both management and workers, aging equipment, inadequate and ineffective dust extraction systems or usually none especially for hand held tools, poor maintenance of the ventilation system in some, non-segregation of dusty processes, dry sweeping, and the use of compressed air jets. The determinant-of-exposure analysis confirmed the field observations. The significant determinants of personal inhalable dust exposures (n=163) were found to be: local exhaust ventilation, job title, use of hand-held tools, cleaning method used, use of compressed air, and green or dry wood processed. Type of wood processed was not found to be statistically significant. A majority of workers (~90%) did not wear appropriate respirators approved for wood dust, while the workers who did wear them, used them on average less than 50% of the time. Workers should be protected by controlling dust at its source. When exposure to wood dust cannot be avoided, engineering controls should be supplemented with the use of appropriate personal protective equipment.

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2

Alwis, Kuruppuge Udeni. "Occupational Exposure to Wood Dust." University of Sydney, Department of Public Health and Community Medicine, 1998. http://hdl.handle.net/2123/392.

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ABSTRACT Occupational exposure to wood dust and biohazards associated with wood dust (endotoxins, (1->3)-b-D-glucans, Gram (-)ve bacteria and fungi), their correlation to respiratory function, and symptoms among woodworkers have been investigated in the present study. Wood dust, endotoxins, and allergenic fungi are the main hazards found in woodworking environments. Relatively very few studies have been done on wood dust exposure. The present study was designed to comprehensively investigate the health effects of wood dust exposure, and in particular provide new information regarding: Exposure to (1->3)-b-D-glucans in an occupational environment; Levels of exposure to wood dust and biohazards associated with wood dust in different woodworking environments; Correlations among personal exposures, especially correlations between (1->3)-b-D-glucans and fungi exposures, and endotoxins and Gram (-)ve bacteria exposures; Effects of personal exposure to biohazards on lung function; Effects of personal exposure to biohazards on work-related symptoms; and Determinants of inhalable exposures (provide which factors in the environment influence the personal inhalable exposures). Workers at four different woodworking processes; two logging sites, four sawmills, one major woodchipping operation and five joineries situated in the state of New South Wales in Australia were studied for personal exposure to inhalable dust (n=182) and respirable dust (n=81), fungi (n=120), Gram (-)ve bacteria (n=120), inhalable endotoxin (n=160), respirable endotoxin (n=79), inhalable (1->3)-b-D-glucan (n=105), and respirable (1->3)-b-D-glucan (n=62). The workers (n=168) were also tested for lung function. A questionnaire study (n=195) was carried out to determine the prevalence of work-related symptoms. The geometric mean inhalable exposure at logging sites was 0.56 mg/m3 (n=7), sawmills 1.59 mg/m3 (n=93), the woodchipping mill 1.86 mg/m3 (n=9) and joineries 3.68 mg/m3 (n=66). Overall, sixty two percent of the exposures exceeded the current standards. Among joineries, 95% of the hardwood exposures and 35% of the softwood exposures were above the relevant standards. Compared with green mills, the percentage of samples, which exceeded the hardwood standard was high for dry mills (70% in dry mills, 50% in green mills). The respirable dust exposures were high at the joineries compared with the other worksites. Exposure levels to fungi at logging sites and sawmills were in the range 103-104 cfu/m3, woodchipping 103-105 cfu/m3 and joineries 102-104 cfu/m3. The predominant fungi found at sawmills were Penicillium spp. High exposure levels of Aureobasidium pullulans were also found at two sawmills. At the woodchipping mill the predominant species were Aspergillus fumigatus, Penicillium spp., and Paecilomyces spp. The sawmills, which employed kiln drying processes, had lower exposure levels of fungi compared with the green mills. Those workplaces which had efficient dust control systems showed less exposure to fungi and bacteria. Although mean endotoxin levels were lower than the suggested threshold value of 20 ng/m3, some personal exposures at sawmills and joineries exceeded the threshold limit value. The mean inhalable (1->3)-b-D-glucan level at the woodchipping mill was 2.32 ng/m3, at sawmills 1.37 ng/m3, at logging sites 2.02 ng/m3, and at joineries 0.43 ng/m3. For the respirable size fraction, mean endotoxin and mean (1->3)-b-D-glucan concentrations were much lower, being similar to observed dust concentrations. Significant correlations were found between mean inhalable endotoxin and Gram (-)ve bacteria levels (p<0.0001), and mean airborne inhalable (1->3)-b-D-glucan and fungi levels (p=0.0003). The correlations between mean respirable endotoxin levels vs Gram (-)ve bacteria exposure levels (p=0.005), and respirable (1->3)-b-D-glucan exposure levels vs total fungi levels (p=0.005) were also significant. Significant correlations were found between lung function and personal exposures. Multivariate analyses showed that the effect of all the personal exposures on cross-shift decrements in lung function was more prominent among sawmill and chip mill workers compared with joinery workers. Woodworkers had markedly high prevalence of cough, phlegm, chronic bronchitis, frequent headaches, throat and eye irritations, and nasal symptoms compared with controls. Among the woodworkers, smokers had a high prevalence of chronic bronchitis (20%) compared with non-smokers (10%). Some workers also reported a variety of allergy problems due to exposure to various types of wood dust. Both joinery workers and sawmill and chip mill workers revealed significant correlations between work-related symptoms and personal exposures. Chronic bronchitis was significantly correlated with personal exposure to wood dust, endotoxin, (1->3)-b-D-glucan, fungi, and Gram (-)ve bacteria among joinery workers. Whereas among sawmill workers chronic bronchitis was significantly correlated with personal exposure to endotoxin, (1->3)-b-D-glucan, and fungi. Woodworkers showed significant positive correlations between percentage cross-shift change (decrease) in lung function and respiratory symptoms. Significant inverse correlations were also found among percentage predicted lung function and respiratory symptoms. The elevated inhalable dust exposures observed in this study can be explained by a combination of factors, including: lack of awareness of potential health effects of wood dust exposure among both management and workers, aging equipment, inadequate and ineffective dust extraction systems or usually none especially for hand held tools, poor maintenance of the ventilation system in some, non-segregation of dusty processes, dry sweeping, and the use of compressed air jets. The determinant-of-exposure analysis confirmed the field observations. The significant determinants of personal inhalable dust exposures (n=163) were found to be: local exhaust ventilation, job title, use of hand-held tools, cleaning method used, use of compressed air, and green or dry wood processed. Type of wood processed was not found to be statistically significant. A majority of workers (~90%) did not wear appropriate respirators approved for wood dust, while the workers who did wear them, used them on average less than 50% of the time. Workers should be protected by controlling dust at its source. When exposure to wood dust cannot be avoided, engineering controls should be supplemented with the use of appropriate personal protective equipment.

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Edwards, John W. "Biological monitoring of occupational chemical exposure /." Title page, contents and summary only, 1990. http://web4.library.adelaide.edu.au/theses/09PH/09phe2652.pdf.

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Labrèche, France P. "Occupational solvent exposure and mental disorders." Thesis, McGill University, 1989. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=74252.

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A case-referent study was designed to investigate the relationship between occupational solvent exposure and mental disorders. New cases of mental disorder (males, 40 to 69 years old), were individually matched for age and date of admission to hospital patients and neighbors. An occupational history was obtained from 91.7% of the sample (1143 subjects, or 381 'trios'), during a telephone interview or by mail.
No increased risk of mental disorders was found among subjects exposed to moderate levels of solvents, but the risk was elevated--though not to a statistically significant degree--at exposure to high levels. When diagnoses were divided into psychotic (ICD-9 codes 290-299) and non-psychotic (ICD-9 codes 300-316), the latter group presented an increased risk with exposure to high levels of solvents (odds ratio = 2.43, 90% C.I. = 1.16-5.08). No systematic exposure-response relationship was demonstrated, although there was a suggestion of increased risk of mental disorders among subjects exposed to high levels for 5 to 9 years.
Various aspects of referent selection--with a specific comparison of hospital and population referents--were also examined as a methodological issue of case-referent studies.

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5

Nilsson, Helena. "Occupational exposure to fluorinated ski wax." Doctoral thesis, Örebro universitet, Institutionen för naturvetenskap och teknik, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:oru:diva-24289.

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Per- and polyfluorinated substances (PFAS) are used in the production of ski wax to reduce the friction between the snow and the ski. In this occupational study of ski wax technicians’ exposure to PFAS and particulate aerosol we have collected whole blood (wb) (n =94), air (n =84) and aerosol (n =159) samples at World Cup events from 2007-2011. We have analysed the blood, air and aerosol with respect to 13 perfluorocarboxylic acids (PFCAs), 4 perfluorosulfonic acids (PFSAs), 3 fluorotelomer alcohols (FTOHs), 3 fluorotelomer acids (FTCAs) and 3 unsaturated fluorotelomer acids (FTUCAs). Further, we assessed the exposure to 3 particulate aerosol fractions (inhalable, respirable and total aerosol) in air. In comparison to a general population, several of the PFCA blood levels are elevated in the technicians’, primarily erfluorooctanoate (PFOA) and perfluorononate (PFNA) with concentrations up to 628 and 163 ng/mL wb, respectively. Further, we detected FTUCAs and FTCAs in the blood, suggesting biotransformation of FTOHs to PFCAs. The metabolites 5:3 and 7:3 FTCA were detected in all blood samples at levels up to 6.1 and 3.9 ng/mL wb. Levels of perfluorohexadecanoic acid PFHxDA) and perfluorooctadecanoic acid (PFOcDA) were detected in the technician’s blood at mean concentration up to 4.22 ng/mL wb and 4.25 ng/mL wb. The FTOH levels in air of the wax cabin during work ranged up to 997 000 ng/m3 (average=114 000 ng/m3 ) and PFOA up to 4 890 ng/m3 (average= 526 ng/m3 . FTOHs were not detected in aerosols but PFOA showed average levels of 12 000 ng/m3 (range=1 230- 46 900 ng/m3 ). The occupational exposure limit (OEL) of 2 mg/m3 was exceeded in 37% of the personal measurements with aerosol concentrations up to 15 mg/m3 . Keywords : Perfluorinated, polyfluorinated, FIS, occupational exposure, ski wax, iotransformation, metabolism, fluorotelomer alcohol, fluorotelomer acid, aerosol, dust, UPLC/MS-MS, GC/MS-MS

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Woltman, Adrianna J. "Assessing the Occupational Nosie Exposure of Bartenders." Scholar Commons, 2015. http://scholarcommons.usf.edu/etd/5800.

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The Occupational Safety and Health Administration estimates that each year, approximately 30 million people are occupationally exposed to hazardous noise. While many are aware of the noise exposure associated with industrial occupations, there has been little research conducted on bartenders who often work in environments that have high levels of noise. The majority of current published research on occupational noise exposure of bartenders has only evaluated noise levels on one night of business. Bartenders often work multiple days per week, which vary in the amount of patrons and entertainment provided, this variation in business leads to variation in the amount of noise to which they are exposed. The purpose of this research study was to gather occupational noise exposure data for bartenders during a workweek at a Tampa Bay bar establishment that hosts live music on weekends. Personal noise dosimeters were used to collect personal noise exposure data. Area noise level data were collected using a sound level meter. While several bar establishments were approached, one bar establishment part pated as the study site and noise data were collected for seven consecutive days (Thursday-Wednesday). Personal noise exposure data were collected for an entire 8-hour work shift for the Thursday-Sunday portion of the study, and for 6 hours for the Monday-Wednesday portion of the study. Area noise data were collected for the Thursday-Saturday portion of the study. Results of this study indicate that the highest noise exposure for either bartender occurred on Saturday (Bartender 1: 93.1 dBA; Bartender 2: 83.6 dBA) when a live band was performing in the establishment. Using the OSHA Hearing Conversation and OSHA PEL measurement methods, Bartender 1 was exposed to excessive noise levels (>85 dBA) on four (4) nights of the study, while Bartender 2 had no exposures over 85 dBA. However, using the ACGIH measurement method, Bartender 1 was exposed to excessive noise levels six (6) nights of the study, while Bartender 2 was exposed to excessive noise levels two (2) nights of the study.

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Cherry, Nicola. "Organic brain damage and occupational solvent exposure." Thesis, McGill University, 1991. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=60012.

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309 cases of organic dementia, cerebral atrophy or psycho-organic syndrome, admitted for 5 days or more to one of 18 Quebec hospitals, were individually matched to a psychiatric referent, admitted with some other diagnosis, and a general hospital referent. Lifetime occupational history was obtained by telephone. Occupational solvent exposure was assessed by (i) individual ratings blind to case status and (ii) a job-exposure matrix. Subjects working with moderate or high solvent concentrations for at least 10 years were considered exposed. With the psychiatric referent series an odds ratio of 1.44 (90% CI 1.03-2.01) was calculated for individual exposure ratings and 1.41 (90% CI 0.89-2.23) for the job matrix. The increased risk was found largely in those with diagnoses of both organic dementia or cerebral atrophy and an alcohol related condition. A similar pattern of risk was found with the general hospital referents. Adjustment for possible confounders did not appreciably alter the risk estimates.

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Woltman, Adrianna J. "Assessing the Occupational Noise Exposure of Bartenders." Thesis, University of South Florida, 2015. http://pqdtopen.proquest.com/#viewpdf?dispub=1595819.

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The Occupational Safety and Health Administration estimates that each year, approximately 30 million people are occupationally exposed to hazardous noise. While many are aware of the noise exposure associated with industrial occupations, there has been little research conducted on bartenders who often work in environments that have high levels of noise. The majority of current published research on occupational noise exposure of bartenders has only evaluated noise levels on one night of business. Bartenders often work multiple days per week, which vary in the amount of patrons and entertainment provided, this variation in business leads to variation in the amount of noise to which they are exposed.

The purpose of this research study was to gather occupational noise exposure data for bartenders during a workweek at a Tampa Bay bar establishment that hosts live music on weekends. Personal noise dosimeters were used to collect personal noise exposure data. Area noise level data were collected using a sound level meter. While several bar establishments were approached, one bar establishment part pated as the study site and noise data were collected for seven consecutive days (Thursday-Wednesday). Personal noise exposure data were collected for an entire 8-hour work shift for the Thursday-Sunday portion of the study, and for 6 hours for the Monday-Wednesday portion of the study. Area noise data were collected for the Thursday-Saturday portion of the study.

Results of this study indicate that the highest noise exposure for either bartender occurred on Saturday (Bartender 1: 93.1 dBA; Bartender 2: 83.6 dBA) when a live band was performing in the establishment. Using the OSHA Hearing Conversation and OSHA PEL measurement methods, Bartender 1 was exposed to excessive noise levels (>85 dBA) on four (4) nights of the study, while Bartender 2 had no exposures over 85 dBA. However, using the ACGIH measurement method, Bartender 1 was exposed to excessive noise levels six (6) nights of the study, while Bartender 2 was exposed to excessive noise levels two (2) nights of the study.

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Yeganeh, Talab Behnoush. "Airborne Nanoparticles: Generation, Characterization, and Occupational Exposure." Thesis, Virginia Tech, 2007. http://hdl.handle.net/10919/41734.

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Despite the rapid growth in nanotechnology, very little is known about the unintended health or environmental effects of manufactured nanomaterials. The development of nanotechnology risk assessments and regulations requires quantitative information on the potential for exposure to nanomaterials. In addition, to facilitate life-cycle assessments and inhalation toxicology studies, robust methods are needed to generate aerosolized engineered nanoparticles. We conducted a set of field studies to measure the fine particle mass concentrations (PM2.5) as well as nanoparticle number concentrations and size distributions in two nanomaterial manufacturing facilities. Measurements were performed near the reactor, in the breathing zone, and at a background site. Increases in PM2.5 and particle number concentrations were associated with physical handling of nanomaterials. The highest PM2.5 concentration observed was 2700 ug m-3 during sweeping of the reactor in the commercial plant. In most cases, an increase in the number of sub-100 nm particles accounted for the increase in total number concentrations. The results of this research can be used to develop guidelines for workplace regulations to minimize workers' exposure to nanoparticles. Furthermore, we used an atomizer to aerosolize C60 aggregates from a fullerene-water suspension. Measurement of particle size distributions and number concentrations showed that increasing the initial fullerene concentration resulted in increased number of aerosolized particles, while the average size of particles remained relatively constant. To return the aerosolized fullerenes into water, we passed the aerosol sample through an impinger. Reducing the flow rate through the impinger resulted in an increase in the collection efficiency of airborne nanoparticles.
Master of Science

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Daniels, Robert D. "Leukemia Mortality and Occupational Ionizing Radiation Exposure." University of Cincinnati / OhioLINK, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1319487627.

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Amasay, Tal. "Unconstrained humeral elevation exposure in occupational settings /." Connect to title online (Scholars' Bank) Connect to title online (ProQuest), 2008. http://hdl.handle.net/1794/8520.

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Thesis (Ph. D.)--University of Oregon, 2008.
Typescript. Includes vita and abstract. "This dissertation includes unpublished co-authored material"--P. v. Includes bibliographical references (leaves 119-128). Also available online in Scholars' Bank; and in ProQuest, free to University of Oregon users.

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Schenk, Linda. "Managing chemical risk through occupational exposure limits /." Stockholm : Arkitektur och samhällsbyggnad, Kungliga Tekniska högskolan, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-9769.

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Hedmer, Maria. "Monitoring of occupational exposure to antineoplastic drugs." Malmö : Lund University, 2006. http://theses.lub.lu.se/scripta-archive/2006/04/18/med_1298/Maria_H_kappa.pdf.

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Amasay, Tal 1968. "Unconstrained humeral elevation exposure in occupational settings." Thesis, University of Oregon, 2008. http://hdl.handle.net/1794/8520.

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xvi, 128 p. A print copy of this thesis is available through the UO Libraries. Search the library catalog for the location and call number.
There were two primary goals of this work. The first goal was to investigate humeral and scapular kinematics in a simulated workplace environment. The second goal was to validate a triaxial accelerometer (Virtual Corset) for the collection of humeral elevation exposure data in an occupational setting. To achieve the first goal, healthy subjects were asked to perform constrained and functional humeral elevation motions. Differences were observed in scapular kinematics. In addition, the variability between constrained arm elevation and functional overhead tasks was found to be similar. Therefore, to compare scapular kinematics in an occupational group (dental hygienists) a functional work related task was determined to be more appropriate. The dental hygienists performed teeth instrumentation on simulated patients' with both big and average chest girth in a simulated work environment. Dental hygienist's humeral elevation and scapular upward rotation angles were found to be higher while working on the big chest girth manikin. These differences may increase dental hygienists susceptibility for musculoskeletal disorders. To achieve the second goal, an in-vitro comparison of angles measured with the Virtual Corset and an inclinometer was conducted under static conditions. Under dynamic conditions the Virtual Corset was compared to a potentiometer, in a pendulum setting. It was found that the Virtual Corset can accurately reconstruct elevation angles under static conditions, root mean square error less than 1[white square]. Under dynamic conditions, the error size was related to the angular velocity and acceleration, and the radius of rotation. To further investigate the Virtual Corset's ability to measure exposure parameters in-vivo the Virtual Corset was compare to a magnetic tracking device. To do so dental hygienists performed flossing tasks in a simulated work station. It was found that the Virtual Corset can be used to reconstruct elevation angles, with an acceptable angle error, and to identify exposure parameters in occupational settings similar to the one simulated in the present study. This dissertation includes unpublished co-authored material.
Adviser: Andrew R. Karduna

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Schenk, Linda. "Management of chemical risk through occupational exposure limits." Licentiate thesis, KTH, Philosophy and History of Technology, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-9769.

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Occupational Exposure Limits (OELs) are used as an important regulatory instrument to protect workers’ health from adverse effects of chemical exposures. The OELs mirror the outcome of the risk assessment and risk management performed by the standard setting actor. In paper I the OELs established by 18 different organisations or national regulatory agencies from the industrialised world were compared. The comparison concerned: (1) what chemicals have been selected and (2) the average level of exposure limits for all chemicals. In paper II the OELs established by 7 different national regulatory agencies of EU member states are compared to those of the European Commission (EC). In addition to the same comparisons as performed in the first study a comparison level was introduced (3) the similarity between the OELs of these EU member states and the OELs recommended by the EC.

List of OELs were collected through the web-pages of, and e-mail communication with the standard-setting agencies. The selection of agencies was determined by availability of the lists. The database of paper I contains OELs for a total of 1341 substances; of these 25 substances have OELs from all 18 organisations while more than one third of the substances are only regulated by one organisation alone. In paper II this database was narrowed down to the European perspective. The average level of OELs differs substantially between organisations; the US OSHA exposure limits are (on average) nearly 40 % higher than those of Poland. Also within Europe there was a nearly as large difference. The average level of lists tends to decrease over time, although there are exceptions to this. The similarity index in paper II indicates that the exposure limits of EU member states are converging towards the European Commission’s recommended OELs. These two studies also showed that OELs for the same substance can vary significantly between different standard-setters. The work presented in paper III identifies steps in the risk assessment that could account for these differences. Substances for which the level of OELs vary by a factor of 100 or more were identified and their documentation sought for further scrutiny. Differences in the identification of the critical effect could explain the different level of the OELs for half of the substances. The results reported in paper III also confirm the tendency of older OELs generally being higher. Furthermore, several OELs were more than 30 years old and were based on out-dated knowledge. But the age of the data review could not account for all the differences in data selection, only one fifth of the documents referred to all available key studies. Also the evaluation of the key studies varied significantly.

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Nassrallah, Flora G. "Measurement of Occupational Sound Exposure from Communication Headsets." Thesis, Université d'Ottawa / University of Ottawa, 2016. http://hdl.handle.net/10393/34577.

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Increased use of communication headsets found in various workplaces raises concerns regarding exposure to potentially hazardous noise levels. Current national and international standards specify a wide range of simple and specialized methods for the measurement of sound exposure under communication headsets. However, to date, quantitative data comparing the degree of agreement between the different measurement methods or their relative performance are lacking, and it is not known if occupational health and safety (OHS) or hearing loss prevention (HLP) stakeholders have the necessary training and equipment to integrate them in their daily practice. A three-step study addressing several knowledge gaps on this topic is presented in this thesis. First, a questionnaire survey distributed to OHS and HLP stakeholders has revealed that knowledge of specialized measurement techniques and access to the necessary equipment varies significantly depending on the training of the different professionals. There is therefore reason to specify several methods in measurement standards to meet the specific needs and expertise of the different stakeholders involved. Second, a series of experiments conducted with single and multiple expert participants indicated that the Type 1 artificial ear is not suited for sound exposure measurement with communication headsets, while Type 2 and Type 3.3 artificial ears are in good agreement with the acoustic manikin technique specified in the International standard ISO 11904-2. Finally, laboratory experiments were conducted to test the indirect calculation method proposed in the Canadian standard CSA Z107.56. Results revealed that the calculation method is suitable to identify possible situations of exposure over the regulatory limit (e.g. 85 dBA), but refinements are proposed to improve measurement accuracy. Overall, this thesis provides new knowledge to guide selection of the most suitable methods for the assessment of communication headset exposure taking into account expertise, access to equipment, and field logistic constraints. Results also have direct implications for future revisions of existing measurement standards. Finally, this work could be the basis for detailed guidelines on noise exposure measurements under communication headsets to better inform OHS and HLP professionals and ultimately prevent occupational noise-induced hearing loss.

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Jorna, Timotheus Hendrikus Johannes Maria. "Analysis of respiratory impairment due to occupational exposure." [Maastricht : Maastricht : Rijksuniversiteit Limburg] ; University Library, Maastricht University [Host], 1994. http://arno.unimaas.nl/show.cgi?fid=6630.

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18

Håkansson, Niclas. "Occupational exposure to electromagnetic fields and chronic diseases /." Stockholm, 2003. http://diss.kib.ki.se/2003/91-7349-719-3/.

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19

Raji, Olaide Yaqeen. "Parental occupational exposure and risk of childhood cancer." Thesis, University of Leeds, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.491636.

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The risk of childhood cancer has been inconsistently linked with parental exposure to occupational agents, partly because of poor exposure assessment. Data from the UK Childhood Cancer Study,. a nationwide population based case-control study, was used to extend previous analyses ofparental occupational exposures assessed via job and industry titles. Eight specific work related exposures were examined as possible risk factors for childhood leukaemia and lymphoma for three exposure time windows (preconception, pregnancy, postnatal). Personal interview data from parents of cases and matched controls included a full occupational history; for each job where exposure had been indicated, detailed information was gathered on each reported exposure agent. A new exposure assessment method was designed, which scrutinised five exposure determinants to provide semi-quantitative indices on exposure probability, level of exposure, frequency of contact, and degree of protection. These were combined to derive a final 'reviewed' exposure status. The method was externally validated against an independent expert assessment. Multivariable unconditional logistic regression estimated odds ratios and 95% confidence intervals for 'self-reported' and 'reviewed' exposures. Mothers had a lower prevalence of exposure (18%) comparedÃ‚Â· to fathers (44%). The 'reviewed' exposure status reclassified 33% of 4833 mothers' and 50% of 19,326 fathers' reported job exposures as 'exposed'. Many statistically significant risks for 'self-reported' exposure disappeared when applying the reclassified exposure. Only maternal exposure to solvents during pregnancy remained statistically significantly associated with acute lymphoblastic leukaemia (ALL) (OR=2.7, C.I=1.6-4.6) with evidence of a dose-response relationship. Paternal exposure to fertilisers during pregnancy and postnatally also remained statistically significantly associated with ALL and Hodgkin Lymphoma but without evidence of dose-response relationships. The designed exposure assessment method represents a novel approach for evaluating parental occupational exposure for use in future studies. The findings for mothers for the generic group of solvents warrants further independent research. Overall, findings must invoke caution in the interpretation of risk estimates reliant on 'selfreported' occupational exposure in epidemiological investigations.

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Azari, Mansur Rezazadeh. "Biological markers of occupational exposure to nitrogen oxides." Thesis, University of Newcastle Upon Tyne, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.261238.

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Khalade, Abdul. "Occupational exposure to benzene and risk of cancer." Thesis, University of Birmingham, 2010. http://etheses.bham.ac.uk//id/eprint/1076/.

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This thesis assessed the risk of cancer in relation to exposure from benzene at work. The thesis is in three major sections. The first section consisted of a systematic review and meta-analysis to assess the risk of leukemia from occupational exposure to benzene. The systematic review confirmed leukemia to be important in relation to benzene exposure; 15 selected studies yielded 16 effect estimates with an overall statistically significant effect size (relative risk) of 1.40 (95% CI, 1.23-1.57). A dose response analysis was performed and provided evidence for a strong positive trend between leukemia risks and estimated exposure to benzene. The risk of all leukemia combined increased with a dose-response pattern with a summary effect size (ES) of 1.64 (95% CI 1.13-2.39) for low (<40 ppm-years), 1.90 (95% CI 1.26-2.89) for medium (40-99.9 ppm-years), and 2.62 (95% CI 1.57-4.39) for high exposure (>100 ppm-years). The risk of AML also increased from low (ES 1.94, 95% CI 0.95-3.95), medium (ES 2.32, 95% CI 0.91-5.94) to high exposure category (ES 3.20, 95% CI 1.09-9.45), but the trend was not statistically significant. The second section used the same method to assess other cancer risks by conducting a systematic review and further meta-analysis. The most common other cancer sites for which a possible occupational involvement from benzene has been suggested were lung, bladder, melanoma, stomach and kidney cancer. Consequently, a systematic review and meta-analysis was performed on each of these cancer sites. The results obtained did not show any clear evidence of risk for lung cancer (ES 0.99, 95% CI 0.96-1.03), bladder cancer (ES 1.00, 95% CI 0.96-1.03), or stomach cancer (ES 0.96, 95% CI 0.90-1.03). However increased risks were shown for melanoma (ES 1.25, 95% CI 1.09-1.44) and kidney cancer (ES 1.14, 95% CI 1.04-1.25). The systematic review and meta-analysis for melanoma was based on 7 available studies reporting 8 cohorts. It was not possible to conclude that benzene exposure is a cause of melanoma as many other chemicals were also used in the factories. There was no significant heterogeneity in the study-specific findings for melanoma (P=0.26). The systematic review and meta-analysis for kidney cancer was based on 22 available studies reporting 24 cohorts. There was also no significant heterogeneity in the study-specific findings for kidney cancer (P=0.41). Therefore, further research is needed to establish a strong link between exposure to benzene and risk of kidney cancer. The final section of the thesis examined the risk of leukemia, lung cancer and all cause mortality in workers exposed to benzene in a large cohort of workers employed at 233 factories during 1966/67 in England & Wales. The results however provided no clear evidence of a dose response effect for leukemia risks in relation to estimated cumulative exposure from benzene. The major limitations of the study related to the recording of limited work histories and the collection of incomplete or limited exposure assessments. The method used in recording the levels of exposure were not clear as different factories were measured by individual personnel at differing times over the years, and at differing areas within factory to factory. It was not possible, therefore, to gain a comprehensive and consistent exposure assessment throughout the factories. To obtain an accurate and viable outcome there needs to be a sound measurement of exposure technique implemented such as taking personal samples using a personal sampler for each individual and indicating specific areas where low, medium and high exposures are evident alongside adequate ventilation. Job exposure matrix also needs to be considered alongside socio-economic classification and ethnicity as this may show some effect on how different minorities may be better or worse adapted to certain chemical exposures.

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Garzon-Villalba, Ximena Patricia. "Assessment of Prolonged Occupational Exposure to Heat Stress." Thesis, University of South Florida, 2016. http://pqdtopen.proquest.com/#viewpdf?dispub=10142405.

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Heat stress is a recognized occupational hazard present in many work environments. Its effects increase with increasing environmental heat loads. There is good evidence that exertional heat illness is associated with ambient thermal conditions in outdoor environments. Further, there is reason to believe that risk of acute injury may also increase with the ambient environment. For these reasons, the assessment of heat stress, which can be done through the characterization of the wet bulb globe temperature (WBGT), is designed to limit exposures to those that could be sustained for an 8-h day. The ACGIH Threshold Limit Value (TLV) for heat stress was based on limited data from Lind in the 1960s. Because there are practical limitations of using thermal indices, measurement of physiological parameters, such as body temperature and heart rate are used with environmental indices or as their alternative.

The illness and injury records from the Deepwater Horizon cleanup effort provided an opportunity to examine the effects of ambient thermal conditions on exertional heat illness and acute injury, and also the cumulative effect of the previous day’s environmental conditions. The ability of the current WBGT-based occupational exposure limits to discriminate unsustainable heat exposures, and the proposal of alternative occupational limits was performed on data from two progressive heat stress protocol trials performed at USF. The USF studies also provided the opportunity to explore physiological strain indicators (rectal temperature, heart rate, skin temperature and the Physiological Strain Index) to determine the threshold between unsustainable and sustainable heat exposures. Analysis were performed using Poisson models, conditional logistic regressions, logistic regressions, and receiver operator curves (ROC curves).

It was found that the odds to present an acute event, either exertional heat illness or acute injuries increased significantly with rising environmental conditions above 20 °C (RR 1.40 and RR 1.06, respectively). There was evidence of the cumulative effect from the prior day’s temperature and increased risk of exertional heat illness (RRs from 1.0–10.4). Regarding the accuracy of the current TLV, the results of the present investigation showed that this occupational exposure limit is extremely sensitive to predict cases associated with unsustainable heat exposures, its area under the curve (AUC) was 0.85; however its specificity was very low (specificity=0.05), with a huge percentage of false positives (95%). The suggested alternative models improved the specificity of the occupational exposure limits (specificities from 0.36 to 0.50), maintaining large AUCs (between 0.84 and 0.89). Nevertheless, any decision in trading sensitivity for specificity must be taken with extreme caution because of the steeped increment risk of heat related illness associated with small increments in environmental heat found also in the present study. Physiologic heat strain indices were found as accurate predictors for unsustainable heat stress exposures (AUCs from 0.74 to 0.89), especially when measurements of heart rate and skin temperature are combined (AUC=0.89 with a specificity of 0.56 at a sensitivity=0.95). Their implementation in industrial settings seems to be practical to prevent unsustainable heat stress conditions.

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Garzon-Villalba, Ximena Garzon-Villalba. "Assessment of Prolonged Occupational Exposure to Heat Stress." Scholar Commons, 2016. http://scholarcommons.usf.edu/etd/6240.

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Heat stress is a recognized occupational hazard present in many work environments. Its effects increase with increasing environmental heat loads. There is good evidence that exertional heat illness is associated with ambient thermal conditions in outdoor environments. Further, there is reason to believe that risk of acute injury may also increase with the ambient environment. For these reasons, the assessment of heat stress, which can be done through the characterization of the wet bulb globe temperature (WBGT), is designed to limit exposures to those that could be sustained for an 8-h day. The ACGIH Threshold Limit Value (TLV) for heat stress was based on limited data from Lind in the 1960s. Because there are practical limitations of using thermal indices, measurement of physiological parameters, such as body temperature and heart rate are used with environmental indices or as their alternative. The illness and injury records from the Deepwater Horizon cleanup effort provided an opportunity to examine the effects of ambient thermal conditions on exertional heat illness and acute injury, and also the cumulative effect of the previous day’s environmental conditions. The ability of the current WBGT-based occupational exposure limits to discriminate unsustainable heat exposures, and the proposal of alternative occupational limits was performed on data from two progressive heat stress protocol trials performed at USF. The USF studies also provided the opportunity to explore physiological strain indicators (rectal temperature, heart rate, skin temperature and the Physiological Strain Index) to determine the threshold between unsustainable and sustainable heat exposures. Analysis were performed using Poisson models, conditional logistic regressions, logistic regressions, and receiver operator curves (ROC curves). It was found that the odds to present an acute event, either exertional heat illness or acute injuries increased significantly with rising environmental conditions above 20 °C (RR 1.40 and RR 1.06, respectively). There was evidence of the cumulative effect from the prior day’s temperature and increased risk of exertional heat illness (RRs from 1.0–10.4). Regarding the accuracy of the current TLV, the results of the present investigation showed that this occupational exposure limit is extremely sensitive to predict cases associated with unsustainable heat exposures, its area under the curve (AUC) was 0.85; however its specificity was very low (specificity=0.05), with a huge percentage of false positives (95%). The suggested alternative models improved the specificity of the occupational exposure limits (specificities from 0.36 to 0.50), maintaining large AUCs (between 0.84 and 0.89). Nevertheless, any decision in trading sensitivity for specificity must be taken with extreme caution because of the steeped increment risk of heat related illness associated with small increments in environmental heat found also in the present study. Physiologic heat strain indices were found as accurate predictors for unsustainable heat stress exposures (AUCs from 0.74 to 0.89), especially when measurements of heart rate and skin temperature are combined (AUC=0.89 with a specificity of 0.56 at a sensitivity=0.95). Their implementation in industrial settings seems to be practical to prevent unsustainable heat stress conditions.

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Ogunyemi, Adekunle. "Occupational Noise Exposure Evaluation of Airline Ramp Workers." Scholar Commons, 2018. http://scholarcommons.usf.edu/etd/7205.

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Noise exposure is a common hazard to workforce in general although at varying degrees depending on the occupation, as many workers are exposed for long periods of time to potentially hazardous noise. Every year, twenty-two million workers are exposed to potentially damaging noise at work. In 2015 U.S. businesses paid over $1.5 million in penalties for not protecting workers from noise. (OSHA, 2016). There may be a direct or indirect consequence of the possibilities of overexposure to noise notwithstanding the compulsory hearing protection requests for the occupations with potential hazards, and these exposures usually arise from the various types of heavy repair equipment and tools related to the job functions. In the United States ten million people have noise related hearing loss (CDC, 2016) and damage done to the ear is not noticed until earing diminishes significantly. One of the noisiest occupations there are include the flight ground crews and flight maintenance personnel otherwise categorized as Ground Operation Workers. These categories of workers have varying functions in the noisiest area at the ramp, and this exposes them to noise that could lead to hearing impairment or permanent ear damage. This study was focused on workers on the ramps at the international airport of a large US city. These workers also are known as ground handling staff, and these employees perform different tasks on the airline ramp, which include unloading luggage from the airline, picking up and moving luggage from the belt room, and to loading baggage onto the airline. This study was conducted using personal dosimeters which were calibrated before and after each sampling event out on four different employees over a period of four days and the collected data were downloaded to a personal computer for further analysis. From the results of this study, the highest noise exposures occurred on a ground operation worker 3 (GOW3) with an 8-hr TWA exposure of 85.6 dBA using OSHA PEL measurement specifications and this occurred on the fourth day of sampling which was a Saturday. The second highest exposure occurred on ground operation worker 1 (GOW1) on the fourth day with an 8-hr TWA exposure of 85.0 dBA. For ground operations worker 2 (GOW2) and ground operation worker 4 (GOW4), the highest exposure occurred on the second day with 79.8 dBA and 73.4 dBA as their time weighted averages, respectively. None of the workers exposures exceeded the OSHA permissible exposure limit of 90 dBA. The United States Navy uses the OSHA noise standard to evaluate noise exposure on ships and all Navy installations. According to University of South Florida institutional review Board, this study is categorized as a program evaluation that has no intervention with human subjects. The workers that participated in this study did so voluntarily.

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Jones, Sherry Lynn. "Nurses' Occupational Trauma Exposure, Resilience, and Coping Education." ScholarWorks, 2016. https://scholarworks.waldenu.edu/dissertations/2360.

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Nursing education courses and professional development (PD) do not include coping and resilience training for registered nurses (RNs) who work in emergency departments (EDs). Exposure to traumatic events, death, and dying may lead to health issues, substance abuse, stress symptoms, nursing staff turnover, and compassion fatigue among ED RNs. Without training, the pattern of adverse outcomes may continue. The purpose of this study was to explore ED RNs' experiences with occupational traumatic stress (OTS), and their recommendations for change to nursing PD programs, using a qualitative bounded intrinsic case study. The conceptual framework for this study included social learning and experiential learning theories. Data were collected through semi-structured interviews with 7 licensed and employed ED RNs with more than 1 year in EDs and who volunteered to participate in the study. Data were examined analytically using descriptive, emotion, and patterns coding strategies and In Vivo to identify categories and themes. Based on nurses' experiences, ED RNs require a collaborative team training approach in learning and sharing opportunities regarding preparatory, de-escalation, and self-care strategies to overcome OTS. Based on the findings, a 3-day interactive PD workshop program was created for ED nurses to address those needs. These endeavors may contribute to positive social change by increasing wellness, cohesive ED teamwork, healthy stress management practices, better patient care, and reduced turnover for ED RNs. Furthermore, nurse educators may benefit from adding coping and resilience training to the nursing education curriculum to address and possibly mitigate the effects of OTS.

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26

Vishvakarman, Devasenapathy. "Occupational exposure to ultraviolet radiation in Central Queensland." Thesis, Queensland University of Technology, 1999.

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Fetouri, Bader Mustafa. "Exposure assessment in near-field : methodology and application in FM frequencies for occupational exposure." Electronic Thesis or Diss., Institut polytechnique de Paris, 2021. http://www.theses.fr/2021IPPAT020.

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La radio FM reste populaire chez toutes les catégories du grand public. Les antennes FM sont généralement placées sur des structures métalliques, aussi appelées pylônes, que les travailleurs doivent escalader pour effectuer des travaux de maintenance. La législation exige le contrôle de l’exposition lorsque les travailleurs sont exposés à des émetteurs à haute puissance. L’objectif de cette recherche est de caractériser les champs électromagnétiques dans les environnements des pylônes et d’évaluer l’exposition. Les champs électromagnétiques dans les environnements des pylônes sont généralement dans le champ proche des antennes, mais la caractérisation et la compréhension du champ proche dans la littérature est limitée à des cas spécifiques d’exposition. Cette recherche s’est donc focalisée sur la définition d’une nouvelle méthodologie en généralisant l’évaluation de l’exposition en champ proche. Cette étude a examiné l’environnement des champs proches en analysant des indicateurs de champs électromagnétiques que l’on peut trouver dans les pylônes, pour ensuite générer des champs incidents aléatoires aux caractéristiques similaires. Les champs aléatoires ont été validés et sélectionnés par un procédé, pour ensuite effectuer des simulations FDTD pour évaluer le débit d’absorption spécifique (DAS) .Cinq cents simulations FDTD pour l’évaluation du DAS ont été effectuées. Les résultats montrent une forte corrélation entre le DAS local/corps entiers et le champ électrique moyen. Des modèles de substitution permettant de lier le DAS au champ électrique ont été trouvés en utilisant des techniques de Machine Learning. L’incertitude des résultats de DAS et des modèles de substitution a été quantifiée
FM radio is still popular among all segments of the general population. FM antenna arrays are usually placed on metallic structures known as pylons that workers have to climb in order to do maintenance and repair work. Exposure monitoring is required by regulation when workers are exposed to high-power emitters. The purpose of this research is to characterize electromagnetic fields (EMF) in pylon environments and to assess EMF exposure in such cases.EMF in pylon environments tend to be in the near-field region of the antenna arrays, but the characterization and understanding of such environments in the literature is limited to specific exposure cases. This research has therefore focused on defining a new methodology by generalizing exposure assessment in the near-field.Using field metrics analysis in human-sized volumes, this study analyzed the near-field environments found in the transmission pylons and generated random incident fields that have the same characteristics. The random incident fields were subjected to a validation and selection process in order to be used in FDTD simulations for specific absorption rate (SAR) assessment.Five hundred FDTD simulations for SAR assessments were performed. The results showed a high correlation between local & whole-body SAR and averaged electric field strength. Surrogate models linking SAR to electric field strength were built using machine learning techniques. The uncertainty of the SAR results and the surrogate models was quantified

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Pearton, Jordan. "Playfulness and prenatal alcohol exposure : a comparative study." Master's thesis, University of Cape Town, 2012. http://hdl.handle.net/11427/2983.

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Hay, Melissa Constance. "Noise Exposure in Medical Helicopter Flights." Scholar Commons, 2012. http://scholarcommons.usf.edu/etd/4331.

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The purpose of this project was to evaluate noise exposures of helicopter pilots, nurses and paramedics at a hospital by collecting area and personal samples, determining noise levels inside the helmet, and evaluating the current selection of personal protective equipment (PPE). Measurements gathered during personal sampling were statistically analyzed and calculated using OSHA 1910.95 App A to determine dose, reference duration and the Time-Weighted Average (TWA). Using a mannequin head, with the noise dosimeters in the ears, tests were performed on the headset inside the helmets to determine the sound pressure levels generated from the radio communications at different volume levels. According to our results, the crew is not exposed to hearing levels above the OSHA permissible exposure limit (PEL), because their flight times are usually only 20-30 minutes and the dose not above 22% of the OSHA limit. If the total flight times were 6.5 hours or more, the crew could be above the OSHA PEL. Testing the helmet speakers resulted in a recommendation that the setting not be set above the 6 o'clock position so that the crew would not be exposed to sound pressure levels about 80 dBA

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Sehatzadeh, Shayan. "Occupational exposure to electromagnetic fields and female breast cancer." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp04/mq29212.pdf.

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31

Hagström, Katja. "Occupational exposure during production of wood pellets in Sweden /." Örebro : Department of Natural Sciences, Örebro University, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:oru:diva-1726.

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32

Barzan, Cristian Vasile. "Towards the reduction of occupational exposure to cytotoxic drugs." Thesis, University of British Columbia, 2010. http://hdl.handle.net/2429/29487.

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Background: One of the most powerful and widely used techniques in cancer treatment is the use of cytotoxic drugs in chemotherapy. These drugs are inherently hazardous with many of them causing carcinogenic, mutagenic or teratogenic health outcomes. Occupational exposure to cytotoxic drugs is of great concern due to their lack of selectivity between healthy and unhealthy cells. Widespread cytotoxic drug contamination has been reported in North America, Europe and Australia. Current cleaning protocols for hazardous antineoplastic drugs include the use of disinfectants and oxidizing agents, such as household bleach. Aim: The thesis project focused on two objectives: 1) hypothesize and confirm potential hazardous byproducts arising from cleaning cyclophosphamide, a widely used cytotoxic drugs, with household bleach, a commonly used cleaning agent; 2) develop an effective and safe cleaning agent for cytotoxic drugs in order to prevent and eliminate exposure to these drugs. Methods: The gas chromatograph mass spectrum (GC/MS) was used to analyze the decomposition of cyclophosphamide by household bleach (5.25% hypochlorite). The reaction was conducted in a test-tube and the by-products extracted and derivatized prior to analysis. Multiple cleaning agent compositions were tested on 10x10cm stainless steel plates spiked with the two model cytotoxic drugs, cyclophosphamide and methotrexate. A wipe-sampling procedure was used to determine amount of contamination present on surface post cleaning with different cleaning agent compositions. Analysis of wipes was conducted on a liquid chromatography tandem mass spectrum (LC/MS/MS). Results: Decomposition of cyclophosphamide by household bleach was determined to produce nornitrogen mustard. Production of nor-nitrogen mustard was determined to be dependant to reaction time and volume of household bleach used. A safe and effective cleaning agent for cytotoxic drugs, which acts by dissolving the contamination and not by decomposition, was developed. The cleaning agent was determine to remove >98% (methotrexate) and >95% (cyclophosphamide) of contamination by using a one-wipe procedure. A systematic cleaning protocol is recommended by using a two-wipe procedure followed by the use of isopropanol. Conclusion: Decomposition of cytotoxic drugs on surface can lead to unwanted and hazardous exposure. Cytotoxic drug contamination can be safely removed from surfaces without decomposition.

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Palmer, Keith. "Aspects of human health and occupational exposure to vibration." Thesis, University of Oxford, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.312305.

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Hatjian, Berj Armen. "Risk assessment of occupational exposure to polycyclic aromatic hydrocarbons." Thesis, University of Newcastle Upon Tyne, 1995. http://hdl.handle.net/10443/372.

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A novel strategy was used to assess the risk to health from exposure to polycyclic aromatic hydrocarbons (PAHs), an important class of chemical carcinogens, in workers in the paving and roofing industries using bitumen. The aim was to evaluate the risk of exposure to PAHs at three different stages: these were external exposure "external dose", internal exposure "internal dose" and biological effect "biologically effective dose". The approaches used for quantifying the risk at these stages were ambient monitoring, biological monitoring and biological effect monitoring, respectively. Ambient monitoring was carried out by personal air sampling and measurement of PAH-exposure. Excretion of thioethers (a non-selective biomarker) and 1-hydroxypyrene (a selective biomarker of exposure to pyrene) in urine were determined. Urinary d-glucaric acid, sister chromatid exchange in peripheral blood lymphocytes and micronuclei in exfoliated cells were use for biological effect monitoring. Seven groups of workers were studied. These were office workers, departmental staff and manual workers who were not occupationally exposed to PAHs and who were included as controls, and two groups of payers and roofers who were exposed to bitumen fumes during their work. The ambient monitoring program revealed that concentrations of PAHs in environmental air could be as high as those found in the payers' and roofers' occupational environments. The contribution of these background levels to the external dose of the pa yers and roofers was considerable. Payers and roofers were occupationally exposed to low levels of PAHs. The PAH profile in the personal air sample of the workers was different between the two industries. This was attributed to the presence of PAH-emission sources other than hot bitumen, such as vehicle exhaust. The concentration of naphthalene measured in air samples was a good indicator for identifying the existence of these sources. The quantitative evaluation of the carcinogenic risk inherent in the external dose using the 8 hour TWA concentration as a measuring stick did not seem to be effective due to the low "noise" levels of carcinogenic PAHs present. A semi-quantitative measure of the external exposure was suggested which appeared to be a better reflection of the carcinogenic risk. Urinary thioethers are not sensitive enough to be used as a nonselective biomarker of exposure to low levels of PAHs; however, urinary 1- hydroxypyrene was a good indicator of internal exposure to pyrene and therefore PAHs in bitumen fume. The relationship between 1-hydroxypyrene in urine and specific airborne PAH-exposure indices in the results of the payers, but not the roofers, suggested that the route of exposure in the latter is mainly dermal while that in the payers is more related to respiratory uptake. This observation, however, did not agree with the subjective occupational hygiene assessment where it was observed that the roofers were closer to the source of PAH-emissions due to the nature of their job and both groups did not use any respiratory or personal protective equipment. The measurement of urinary d-glucaric acid excretion suggested, but not strongly, that hepatic enzyme activity was induced in the occupationally PAH-exposed groups in comparison to controls and reflected the internal dose of pyrene or total PAHs. These observation; however, need further investigation. Micronuclei in exfoliated epithelial cells could not be measured in these populations as insufficient bladder epithelial cells were obtained for analysis. Sister chromatid exchange in peripheral blood lymphocytes of payers and roofers was significantly elevated in comparison to control and manual worker group. The group mean frequencies of SCE were significantly correlated with the external exposure to carcinogenic PAHs. This observation suggested that sister chromatid exchange is a very sensitive cytogenetic endpoint and is useful for evaluating the risk of exposure to low levels of carcinogenic PAHs. Risk assessment, such as the one conducted in this study, allows a quantitative estimation of risk associated with long-term exposure to moderate and low levels of airborne exposure to PAHs in bitumen fume. Knowledge of dose response relationship may allow a review of current Occupational Exposure Standards (OES) and Biological Exposure Limits, which are at present either unavailable or based on poor background scientific knowledge for most PAH compounds. In this study we have suggested an Occupational Exposure Limit for PAHs based on the sum of fourteen PAH-species.

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Loury, Sharon D., Ken Silver, Joe Florence, Steve Manock, Amy K. Liebman, Sean O'Connor, Alexis Andino, Nichole Manz, Sam Ashe, and Joe Florence. "Early Occupational Pesticide Exposure in a Migrant Farmworker Population." Digital Commons @ East Tennessee State University, 2012. https://dc.etsu.edu/etsu-works/8203.

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Loury, Sharon D., Karin Hoffman, Ken Silver, Steve Manock, Amy K. Liebman, Sean O'Connor, Alexis Andino, Nichole Manz, Sam Ashe, and Joe Florence. "Early Occupational Pesticide Exposure in a Migrant Farmworker Population." Digital Commons @ East Tennessee State University, 2011. https://dc.etsu.edu/etsu-works/8205.

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INTRODUCTION. The enhanced susceptibility of children and adolescents to the adverse effects of pesticides is a priority of regulatory agencies, whose primary concern is typically the development of risk-based regulations to protect consumers and the general population. An important subpopulation occupationally exposed to pesticides at an early age is the children of migrant and seasonal farmworkers (MSFWs). Because this group is difficult to access, information is sparse on their age distributions and chemical exposure. EPA pesticide regulations do not adequately address these younger workers. METHODS. The regular summer health screenings performed on tomato Farms in East Tennessee by Rural Medical Services Inc., a Community and Migrant Health Center, afforded and opportunity for Students in her professions to engage in community-based research to query MSFWs on issues childhood and adolescent pesticide exposure. RESULTS 132 adults participated, with 19 providing information about 33 of their children. MSFWs began working in agriculture in Mexico or Central America did so at younger ages, with 58.8% age 1838.1% of those who started in U.S. (p=0.038). Weather in the US or in Mexico/Central America the proportion of survey children under 12 years old and they began working around pesticide-treated crops was 13.1%. Wars in tomatoes fields in Southeastern U.S.CONCLUSIONS Children under 12 maybe occupationally exposed. The capital MSFW population is a largely intact source of data on childhood and adolescent occupational exposure to pesticides.

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De, Grosbois Sylvie. "Occupational exposures and airways disease : a study to develop and evaluate a questionnaire for eliciting occupational exposure history for community based studies." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp02/NQ44402.pdf.

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Smith, Eugene N. "Skid Loader Noise Exposure Assessment in a Confinement Dairy Barn." University of Toledo Health Science Campus / OhioLINK, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=mco1290038578.

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McAbee, Roberta Rae. "Occupational health hazards in women and pregnancy outcomes /." Thesis, Connect to this title online; UW restricted, 1991. http://hdl.handle.net/1773/7374.

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Glass, Deborah Catherine, and mikewood@deakin edu au. "Exposure estimation, uncertainty and variability in occupational hygiene retrospective assessment." Deakin University. School of Biological and Chemical Sciences, 1999. http://tux.lib.deakin.edu.au./adt-VDU/public/adt-VDU20051017.142634.

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This thesis reports on a quantitative exposure assessment and on an analysis of the attributes of the data used in the estimations, in particular distinguishing between its uncertainty and variability. A retrospective assessment of exposure to benzene was carried out for a case control study of leukaemia in the Australian petroleum industry. The study used the mean of personal task-based measurements (Base Estimates) in a deterministic algorithm and applied factors to model back to places, times etc for which no exposure measurements were available. Mean daily exposures were estimated, on an individual subject basis, by summing the task-based exposures. These mean exposures were multiplied by the years spent on each job to provide exposure estimates in ppm-years. These were summed to provide a Cumulative Estimate for each subject. Validation was completed for the model and key inputs. Exposures were low, most jobs were below TWA of 5 ppm benzene. Exposures in terminals were generally higher than at refineries. Cumulative Estimates ranged from 0.005 to 50.9 ppm-years, with 84 percent less than 10 ppm-years. Exposure probability distributions were developed for tanker drivers using Monte Carlo simulation of the exposure estimation algorithm. The outcome was a lognormal distribution of exposure for each driver. These provide the basis for alternative risk assessment metrics e.g. the frequency of short but intense exposures which provided only a minimal contribution to the long-term average exposure but may increase risk of leukaemia. The effect of different inputs to the model were examined and their significance assessed using Monte Carlo simulation. The Base Estimates were the most important determinant of exposure in the model. The sources of variability in the measured data were examined, including the effect of having censored data and the between and within-worker variability. The sources of uncertainty in the exposure estimates were analysed and consequential improvements in exposure assessment identified. Monte Carlo sampling was also used to examine the uncertainties and variability associated with the tanker drivers' exposure assessment, to derive an estimate of the range and to put confidence intervals on the daily mean exposures. The identified uncertainty was less than the variability associated with the estimates. The traditional approach to exposure estimation typically derives only point estimates of mean exposure. The approach developed here allows a range of exposure estimates to be made and provides a more flexible and improved basis for risk assessment.

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Chorley, Adrian Carl. "Ocular exposure to occupational non-ionising radiation in professional pilots." Thesis, London South Bank University, 2015. http://researchopen.lsbu.ac.uk/1962/.

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Research evidence supports the link between long term exposure to ultraviolet (UV) and the blue light hazard with ocular damage including cataract and macular degeneration. Population studies to determine the prevalence of these conditions in pilots are inconclusive. It is known that UV and blue light intensities increase with altitude. The aim of this research was to investigate whether professional pilots are adequately protected from UV and short wavelength light during flight. Informed by the results of 22 semi-structured interviews, a questionnaire exploring the eye protection habits of professional pilots was developed and completed by 2,967 participants. The results showed a wide variation in pilot use of sunglasses, uncovered barriers preventing sunglass use and showed a high level of dissatisfaction regarding standard aircraft sun protection systems. In flight irradiance measurements were captured during 6 airline and 4 helicopter flights. No measurable UVB was found. UVA exposure was highly reliant on the transmission properties of the aircraft windshield. Further ground measurements on 15 aircraft showed the majority had windshields which transmit significant levels of UVA into the cockpit. This can cause the ocular dose for the unprotected eye to exceed international recommended exposure limits within 1⁄2 hour of flight. Older aircraft generally had superior UVA blocking windshields. Although calculated retinal exposure to blue light hazard during flight fell well within international recommended limits, the mean radiance was 4.1 times higher at altitude. The effect of this over a flying career remains uncertain. Filter transmittance measurements were taken from 34 pilot sunglasses and 20 new sunglasses typically used by pilots. All sunglasses filters measured offered sufficient protection from UVA in flight and ensured an attenuation of the blue light hazard to levels equivalent to those at ground level without protection. A series of practical recommendations are made to pilots, eye care health professionals, industry and the aviation regulators.

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Gudmundsson, Anders. "Studies on particle size-selective sampling of aerosols relevant for deposition in the human airways and onto the eyes." Lund : Dept. of Industrial Engineering, Division of Working Environment, Lund Institute of Technology, Lund University, 1995. http://books.google.com/books?id=XWZtAAAAMAAJ.

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Elliott, Leshan J. "Validation of two qualitative ocupational exposure assessment models for particulates and vapors." Thesis, Birmingham, Ala. : University of Alabama at Birmingham, 2008. https://www.mhsl.uab.edu/dt/2008p/elliott.pdf.

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Leung, Lisa. "Occupational exposures and cancers in women." Electronic Thesis or Diss., université Paris-Saclay, 2023. http://www.theses.fr/2023UPASR014.

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Contexte : Des résultats issus d'études sur les migrants suggèrent que les facteurs de risque environnementaux peuvent jouer un rôle dans la pathogenèse du cancer du sein, de l'ovaire et du poumon. Néanmoins, l'étiologie de ces cancers reste mal comprise. Bien que les femmes représentent une proportion importante de la main-d'œuvre mondiale, la recherche sur les dangers professionnels auxquels sont exposées les travailleuses demeure limitée. Peu d'études ont examiné les professions fréquentes chez les femmes et les risques professionnels liés aux cancers féminins.Objectifs : Etudier les associations entre 1) la profession, les expositions professionnelles et le cancer de l'ovaire, 2) les expositions professionnelles et le cancer du sein, 3) la profession, les expositions professionnelles et le cancer du poumon.Méthodes : Les données de trois études cas-témoins réalisées dans des populations générales de femmes au Canada et en France, qui recueillaient des informations sur l'historique professionnel, ont été utilisées: l'étude PROVAQ sur le cancer de l'ovaire (491 cas, 897 témoins), l'étude CECILE sur le cancer du sein (1 206 cas, 1 294 témoins) et l'étude WELCA sur le cancer du poumon (731 cas, 751 témoins). Dans ces trois études, un hygiéniste industriel a codé la profession de chaque emploi de chaque participante. Les codes de profession ont été liés à la matrice emplois-expositions canadienne, permettant ainsi de générer des estimations d'exposition pour de nombreux agents. La relation entre l'exposition à chacun des agents les plus répandus et le risque de cancer a été évaluée : 29 agents pour le cancer de l'ovaire, 49 agents pour le cancer du sein et 41 agents pour le cancer du poumon. Pour les cancers de l'ovaire et du poumon, les professions fréquemment rencontrées ont également été examinées. Les associations avec le risque de cancer pour les professions et les expositions professionnelles ont été estimées à l'aide de la régression logistique et en ajustant pour des facteurs de confusion, identifiés à l'aide de graphes acycliques dirigés.Résultats : Des risques accrus de cancer de l'ovaire ont été suggérés pour les professions dans le domaine de la comptabilité, de la vente, de la coiffure et de la couture, ainsi que pour l'exposition professionnelle à des agents liés aux professions de la coiffure. Pour le cancer du sein, l'exposition professionnelle à des agents, en particulier les poussières de fibres textiles, les solvants organiques, les hydrocarbures aromatiques polycycliques, les poussières de plastique et les fumées de pyrolyse, était potentiellement associée à des risques accrus. Il a été suggéré que les risques relatifs diffèrent entre les sous-types de cancer du sein et en fonction du statut ménopausique pour certains agents. Pour le cancer du poumon, des odds ratios élevés ont été observés pour l'enseignement, les professions libérales, les cols-blancs, la vente et les services, ainsi que pour de nombreuses expositions professionnelles, dont certaines étaient cohérentes avec des études antérieures chez les femmes, telles que les fumées de cuisson, le formaldéhyde, les solvants organiques, les hydrocarbures aromatiques polycycliques, les métaux et les peintures/vernis. Les risques de cancer du poumon pour certains agents semblent différer selon le statut tabagique.Conclusions : Certaines professions et expositions professionnelles peuvent être associées à des risques accrus de cancer de l'ovaire, du sein et du poumon chez les femmes. Étant donné que de nombreux résultats étaient imprécis, il est nécessaire de mener d'autres recherches sur des populations générales de femmes afin de reproduire ces résultats. Des études portant sur des échantillons plus importants et l'obtention d'informations provenant de l'évaluation par des experts, permettant d'utiliser des méthodes statiques avancées, peuvent être utiles pour distinguer entre les effets des agents corrélés dans l'estimation du risque de cancer
Background: Evidence from migrant studies suggests that environmental risk factors may play a role in the pathogenesis of breast, ovarian, and lung cancers, yet the etiology of these cancers remains poorly understood. Women account for a significant proportion of the labour force worldwide, yet research on occupational hazards of female workers is limited. Few studies have examined occupations common to women and occupational risks in relation to female cancers.Objectives: The specific objectives of the thesis were: 1) to study the association between occupation, occupational exposures and ovarian cancer, 2) to study the association between occupational exposures and breast cancer, and 3) to study the association between occupation, occupational exposures and lung cancer in women.Methods: Data from three population-based case-control studies on women in Canada and France that collected occupational history information was used to achieve the objectives: the PROVAQ study on ovarian cancer (491 cases, 897 controls), the CECILE study on breast cancer (1,206 cases, 1,294 controls), and the WELCA study on lung cancer (731 cases, 751 controls). In all three studies, an industrial hygienist coded the occupation of each participant's job. Job codes were linked to the Canadian job-exposure matrix, thereby generating exposure estimates for many agents. The relationship between exposure to each of the most prevalent agents and cancer risk was assessed, specifically 29 agents for ovarian cancer, 49 agents for breast cancer, and 41 agents for lung cancer. For ovarian and lung cancers, prevalent occupations were additionally examined by comparing participants employed in an occupation for <10 years and ≥10 years vs. never employed in the occupation. Associations with cancer risk for occupations and occupational exposures were estimated using logistic regression and adjusting for minimally sufficient confounder sets, identified using directed acyclic graphs.Results: Excess ovarian cancer risks were suggested for accountancy, sales, hairdressing, and sewing occupations, and for occupational exposure to agents linked to hairdressing-related occupations. Interpretations of results for single agents were limited due to multiple correlated exposures. For breast cancer, occupational exposure to agents, particularly textile fibre dusts, organic solvents, polycyclic aromatic hydrocarbons, plastic dusts and pyrolysis fumes, were potentially associated with increased risks. Relative risks were suggested to differ among breast cancer subtypes and according to menopausal status for some agents. For lung cancer, elevated odds ratios were observed for teaching, professional, white-collar, sales, and service occupations, and for numerous occupational exposures, some of which were consistent with previous studies in women, such as cooking fumes, formaldehyde, organic solvents, polycyclic aromatic hydrocarbons, metals, and paints/varnishes. Lung cancer risks for some agents were suggested to differ by smoking status.Conclusions: Certain occupations and occupational exposures may be associated with excess ovarian, breast, and lung cancer risks in women. As many odds ratios observed were imprecise, further population-based research on women is warranted to replicate findings. Studies with larger sample sizes and expert assessment information that can perform more advanced statistical methods accounting for multiple exposures may be useful in disentangling the effects of correlated agents in the estimation of cancer risk

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Knipp, Michael J. "Assessment of Municipal Firefighters’ Dermal Occupational Exposure to Polycyclic Aromatic Hydrocarbons." University of Cincinnati / OhioLINK, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1282576940.

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46

Dal, Ufuk. "Assessment Of Occupational Noise Exposure Of A Plant In Oil Industry." Master's thesis, METU, 2010. http://etd.lib.metu.edu.tr/upload/3/12611997/index.pdf.

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Noise, which is a noteworthy problem in the world of workers, influences the health, safety, productivity and efficiency of those working in heavy industries and especially those working in petroleum industry. The objective of this study is to reassess the protective measures, taken previously by the company, from the point of view of the negative effects of noise on the workers. For this purpose, two approaches are adopted. Firstly, through questionnaires (response rate: 86%) distributed to workers, their subjective rating of, the noise levels to which they are exposed, the factors affecting their working efficiency and, their working conditions are searched. Secondly, noise levels, in the buildings rated as highly and very highly noisy, are measured by sound level meter. Self-exposure of 28 workers is measured by dosimeter. The overall ambient noise level of the 11 buildings and effect of noise on the working efficiency of the workers working in these buildings were respectively found to be moderate and slightly affected. The workplace index was 3 (out of 5). The working conditions index was on the average 4 (out of 5). The Leq values measured in six of the buildings were found to be in the range of 66, 8 &ndash
100, 0 dBA. 12 out of 28 workers were observed to be exposed to noise levels greater than 80 dBA. The objective (noise measurements) and subjective (questionnaire) results obtained at the end of the afore-mentioned approaches will be of help in the orientation of the workers while estimating their work efficiency and will also serve as a data base for the planning strategy of the interested company.

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Schenk, Linda. "Setting occupational exposure limits : Practices and outcomes of toxicological risk assessment." Doctoral thesis, KTH, Filosofi, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-29777.

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Occupational Exposure Limits (OELs) are used as an important regulatory instrument to protect workers’ health from adverse effects of chemical exposures. The main objective of this thesis is to study risk assessment practices in the setting of OEL in order to produce knowledge that will help improve the consistency and transparency of OELs. For the purpose of paper I a database of OELs for a total of 1341 substances was compiled. Of these, only 25 substances have OELs from all 18 included organisations while more than one third of the substances are only regulated by one organisation alone. The average level of OELs differs substantially between organisations; the US OSHA exposure limits are (on average) nearly 40 % higher than those of Poland. In paper II six EU member states’ OELs are compared to the European Commission’s OELs. Also within Europe there is a large difference concerning the average level of OELs (35%). The average level of lists tends to decrease over time, although there are exceptions to this. There are also indications that the exposure limits of EU member states are converging towards the European Commission’s OELs. The work presented in paper III identifies steps in the risk assessment that could account for the large differences in OELs for 14 different substances. Differences in the identification of the critical effect could explain the different level of the OELs for half of the substances. But the age of the data review could not account for all the differences in data selection, only one fifth of the documents referred to all available key studies. Also the evaluation of the key studies varied significantly. The aim of paper IV was to investigate how the Scientific Committee on Occupational Exposure Limits (SCOEL) of the European Commission uses assessment factors when proposing health-based indicative OELs. For only one third of the investigated OELs were explicit assessment factors given. On average the safety margin of the recommendations was 2.1 higher when an explicit assessment factor had been used. It is recommended that the SCOEL develop and adhere to a more articulate framework on the use of assessment factors. Paper V focuses on the Derived No-Effect Levels (DNELs) which are to be calculated under the new European Union REACH legislation. It is a comparison of the safety margins of 88 SCOEL recommendations with those of the corresponding worker-DNELs, derived according to the default approach as described in the REACH guidance document. Overall, the REACH safety margins were approximately six times higher than those derived from the SCOEL documentations but varied widely with REACH/SCOEL safety margin ratios ranging by two orders of magnitude, from 0.3 to 58.
QC 20110215

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Meijers, Johannes Mathijs Marie. "Exposure to inorganic dust and occupational diseases epidemiological methods and investigations /." Maastricht : Maastricht : Datawyse ; University Library, Maastricht University [Host], 1991. http://arno.unimaas.nl/show.cgi?fid=5627.

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Farshad, Ali A. "The relationship between occupational exposure, absorption and excretion of solvent vapours." Thesis, University of Newcastle Upon Tyne, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.240981.

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Cherrie, J. W. "Reconstructing the past : estimating exposure to hazardous substances in occupational epidemiology." Thesis, University of Aberdeen, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.338329.

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The aim of the work described in this thesis was to develop a reliable method for retrospective assessment of occupational exposure, for individual workers, to substances hazardous to health. A review of existing methods for reconstructing exposure has shown a diverse range of approaches, partly dictated by the availability of measurement records and other documentation about work activities. These methods show little evidence of a coherent theoretical basis for exposure assessment. Progress has been made in defining a theory of exposure to hazardous substances and in elaborating this for substances where the main route of exposure is by inhalation. A new metric for exposure assessment, i.e. uptake, is proposed. For inhalation this corresponds to the cumulative amount of material inhaled during the exposure period, e.g. for a dust this would correspond to the time integral of the product of exposure level (i.e. concentration) and breathing rate. Analogous definitions are provided for dermal and ingestion uptake, and total uptake as the sum of these individual measures. It is argued that uptake should provide the best metric for reconstructing past exposure. For inhalation exposure several stages have been identified linking emission of hazardous substances from sources to inhalation of the substance by an individual worker. Emission from sources into the work environment has been divided into three parts (i.e. intrinsic emission, plus the effects of handling and local controls), which are assumed to be independent of each other. It is further assumed that the total emission from a source is determined by the product of these terms.

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Dissertations / Theses on the topic 'Occupational exposure'

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