Journal articles on the topic 'Chemicals'
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Lim, Hong Lyuer, Eun-Hae Huh, Da-An Huh, Jong-Ryeul Sohn, and Kyong Whan Moon. "Priority Setting for the Management of Chemicals Using the Globally Harmonized System and Multivariate Analysis: Use of the Mahalanobis-Taguchi System." International Journal of Environmental Research and Public Health 16, no. 17 (August 27, 2019): 3119. http://dx.doi.org/10.3390/ijerph16173119.
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This study aims to provide a new methodology using the Globally Harmonized System (GHS) and the Mahalanobis–Taguchi System (MTS) that can be used to assess the overall hazard of a chemical using GHS information. Previously, hazardous chemicals were designated and managed by the Chemical Management Act, but many more chemicals are now in use. Damage prediction modeling programs predict the extent of damage and proactively manage high-risk chemicals, but the lack of physical and chemical characterization information relating to chemicals has limitations that cannot be modeled. To overcome such limitations, a new method of chemical management prioritization was developed using the GHS and Mahalanobis–Taguchi System (MTS). For effective management, the risk of a chemical can be ranked according to a comprehensive risk assessment and calculated through multivariate analysis using the GHS. Relative hazards are then identified using MTS multivariate analysis with GHS information, even when there is insufficient information about the chemical’s characteristics, and the method can be applied to a large number of different chemicals.
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Skelhorn, John, and Candy Rowe. "Frequency-dependent taste-rejection by avian predation may select for defence chemical polymorphisms in aposematic prey." Biology Letters 1, no. 4 (August 31, 2005): 500–503. http://dx.doi.org/10.1098/rsbl.2005.0359.
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Chemically defended insects advertise their unpalatability to avian predators using conspicuous aposematic coloration that predators learn to avoid. Insects utilize a wide variety of different compounds in their defences, and intraspecific variation in defence chemistry is common. We propose that polymorphisms in insect defence chemicals may be beneficial to insects by increasing survival from avian predators. Birds learn to avoid a colour signal faster when individual prey possesses one of two unpalatable chemicals rather than all prey having the same defence chemical. However, for chemical polymorphisms to evolve within a species, there must be benefits that allow rare chemical morphs to increase in frequency. Using domestic chicks as predators and coloured crumbs for prey, we provide evidence that birds taste and reject proportionally more of the individuals with rare defence chemicals than those with common defence chemicals. This indicates that the way in which birds attack and reject prey could enhance the survival of rare chemical morphs and select for chemical polymorphism in aposematic species. This is the first experiment to demonstrate that predators can directly influence the form taken by prey's chemical defences.
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Jyoti Das, Rashmi. "Chemical Safety Assessment of Inorganic Chemicals used in an Undergraduate Chemistry Laboratory." International Journal of Science and Research (IJSR) 12, no. 8 (August 5, 2023): 348–52. http://dx.doi.org/10.21275/sr23728014319.
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Lee, Hyo Eun, Seok J. Yoon, Jong-Ryeul Sohn, Da-An Huh, Seok-Won Jang, and Kyong Whan Moon. "Suitability Assessment of Legal Regulation of Chemical Concentrations According to Vapor Pressure and Damage Radius." International Journal of Environmental Research and Public Health 16, no. 3 (January 26, 2019): 347. http://dx.doi.org/10.3390/ijerph16030347.
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Many chemicals used in the industrial field present risks, which differ depending on their chemical properties. Additionally, their various physicochemical properties change considerably with concentration. Many chemicals are used in customized processes in factories in the form of different aqueous solutions. The Korean Chemicals Control Act evaluates “hazardous chemicals,” describes their risks to the public, and regulates their concentration. To prepare against chemical accidents, factories construct models of potential damage radius, which is greatly influenced by a chemical’s vapor pressure. This study selected substances with widely varying vapor pressures (hydrogen fluoride, hydrogen chloride, aqueous ammonia, and hydrogen peroxide) and compared the results of different modeling programs (KORA, ALOHA, PHAST, and RMP*Comp) for various aqueous solution concentrations. The results showed that damage radius and vapor pressure increased similarly for each substance. Damage radius was negligible at low concentrations for all substances studied. Damage radius of ammonia solution increased with vapor pressure. Hydrogen fluoride is not found in aqueous solution at concentrations of less than 37%, and hydrogen peroxide does not show a large damage radius at low concentrations. However, the Chemicals Control Act strictly regulates hydrogen fluoride concentration beginning at 1%, hydrogen chloride and aqueous ammonia at 10%, and hydrogen peroxide at 6%. To effectively prepare against chemical accidents, we must examine scientifically-based, suitable regulations based on physicochemical properties.
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Dixon, Holly M., Georgina Armstrong, Michael Barton, Alan J. Bergmann, Melissa Bondy, Mary L. Halbleib, Winifred Hamilton, et al. "Discovery of common chemical exposures across three continents using silicone wristbands." Royal Society Open Science 6, no. 2 (February 2019): 181836. http://dx.doi.org/10.1098/rsos.181836.
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To assess differences and trends in personal chemical exposure, volunteers from 14 communities in Africa (Senegal, South Africa), North America (United States (U.S.)) and South America (Peru) wore 262 silicone wristbands. We analysed wristband extracts for 1530 unique chemicals, resulting in 400 860 chemical data points. The number of chemical detections ranged from 4 to 43 per wristband, with 191 different chemicals detected, and 1339 chemicals were not detected in any wristband. No two wristbands had identical chemical detections. We detected 13 potential endocrine disrupting chemicals in over 50% of all wristbands and found 36 chemicals in common between chemicals detected in three geographical wristband groups (Africa, North America and South America). U.S. children (less than or equal to 11 years) had the highest percentage of flame retardant detections compared with all other participants. Wristbands worn in Texas post-Hurricane Harvey had the highest mean number of chemical detections (28) compared with other study locations (10–25). Consumer product-related chemicals and phthalates were a high percentage of chemical detections across all study locations (36–53% and 18–42%, respectively). Chemical exposures varied among individuals; however, many individuals were exposed to similar chemical mixtures. Our exploratory investigation uncovered personal chemical exposure trends that can help prioritize certain mixtures and chemical classes for future studies.
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Mowat, Douglas. "Chemical Exchange Directory — advertising chemicals online." Online Review 13, no. 4 (April 1989): 305–12. http://dx.doi.org/10.1108/eb024314.
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Brady, Francis. "Chemicals: Membranes meet chemical industry requirements." Filtration + Separation 49, no. 3 (May 2012): 26–29. http://dx.doi.org/10.1016/s0015-1882(12)70143-x.
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Tomassoni, Anthony J., Robert N. E. French, and Frank G. Walter. "Toxic Industrial Chemicals and Chemical Weapons." Emergency Medicine Clinics of North America 33, no. 1 (February 2015): 13–36. http://dx.doi.org/10.1016/j.emc.2014.09.004.
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IDE, FUMIO. "Surface treatment. Chemical modification. Chemicals, graftcopolymerization." NIPPON GOMU KYOKAISHI 59, no. 11 (1986): 601–9. http://dx.doi.org/10.2324/gomu.59.601.
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Lee, Duk-Hee, and David R. Jacobs Jr. "New approaches to cope with possible harms of low-dose environmental chemicals." Journal of Epidemiology and Community Health 73, no. 3 (January 11, 2019): 193–97. http://dx.doi.org/10.1136/jech-2018-210920.
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Low-dose environmental chemicals including endocrine-disrupting chemicals can disturb endocrine, nervous and immune systems. Traditional chemical-focused approaches, strict regulation and avoidance of exposure sources, can help protect humans from individual or several chemicals in the high-dose range, but their value in the low-dose range is questionable. First, exposure sources to problematic environmental chemicals are omnipresent, and many common pollutants present no safe level. In this situation, the value of any effort focusing on individual chemicals is very limited. Second, critical methodological issues, including the huge number of environmental chemicals, biological complexity of mixtures and non-linearity, make it difficult for risk assessment-based regulation to provide reliable permissible levels of individual chemicals. Third, the largest exposure source is already internal; human adipose tissue contains the most complex chemical mixtures. Thus, in the low-dose range, a paradigm shift is required from a chemical-focused to a human-focused approach for health protection. Two key questions are (1) how to control toxicokinetics of chemical mixtures to decrease their burden in critical organs and (2) how to mitigate early harmful effects of chemical mixtures at cellular levels. Many lifestyles can be evaluated for these purposes. Although both the chemical-focused and human-focused approaches are needed to protect humans, the human-focused holistic approach must be the primary measure in the low-dose range of environmental chemicals.
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Edwards, F. G., E. Egemen, R. Brennan, and N. Nirmalakhandan. "Ranking of toxics release inventory chemicals using a level III fugacity model and toxicity." Water Science and Technology 39, no. 10-11 (May 1, 1999): 83–90. http://dx.doi.org/10.2166/wst.1999.0634.
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In an effort to lessen the environmental impact of chemicals discharged by industry, some countries rank chemicals according to mass released each year and then set environmental protection policy based upon this ranking. These rankings have driven industries and companies to change their process configurations and their chemical releases to reduce the release of higher ranking chemicals. But, chemicals that are higher ranked due to mass release may not be particularly toxic nor persistent in the environment; conversely, lower ranked chemicals may be substantially more toxic and persistent in the environment. The physical/chemical properties of forty five organic chemicals from the EPA's Toxic Release Inventory were used as inputs to a Level III fugacity model to estimate fate, transport, and steady state concentrations of chemicals in the environment. The resulting concentrations in the air and water, for each chemical, were determined using the fugacity model and were then compared with toxicity data, the ratio was used as an indication of the environmental impact of the release of each chemical. The chemicals were then ranked according to the degree of environmental impact and the results were compared to other ranking systems reported in the literature.
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Huh, Da-An, Hong Lim, Jong-Ryeul Sohn, Sang-Hoon Byeon, Soonyoung Jung, Woo-Kyun Lee, and Kyong Moon. "Development of a Screening Method for Health Hazard Ranking and Scoring of Chemicals Using the Mahalanobis–Taguchi System." International Journal of Environmental Research and Public Health 15, no. 10 (October 10, 2018): 2208. http://dx.doi.org/10.3390/ijerph15102208.
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For efficient management of chemicals, it is necessary to preferentially select hazardous chemicals as being high-priority through a screening method. Over the past 20 years, chemical ranking and scoring (CRS) methods have been applied in many countries; however, these CRS methods have a few limitations. Most of the existing methods only use some of the variables to calculate the hazard of chemicals or use the most conservative score without consideration of the correlation between chemical toxicities. This evaluation could underestimate or overestimate the real health hazard of the chemicals. To overcome the limitations of these methods, we developed a new CRS method using the Mahalanobis–Taguchi System (MTS). The MTS, which conducts multivariate analysis, produced chemical rankings that took into accounts the correlation between variables related to chemical health hazards. Also, the proportion of chemicals managed by the Korea Chemicals Control Act that were given a high rating appeared to be higher when the MTS was used, compared to the existing methods. These results indicated that the new method evaluated the health hazards of chemicals more accurately, and we expect that the MTS method could be applied to a greater range of chemicals than the existing CRS methods.
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Jain, Neha. "Terrorism at Rise with the Chemicals Insight: Use of Chemical Warfare Agents an Issue of Global Concern." Journal of Forensic Chemistry and Toxicology 9, no. 1 (June 15, 2023): 47–51. http://dx.doi.org/10.21088/jfct.2454.9363.9123.3.
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Crime has led to a worldwide increase with a main weapon of offence including not only a physical object but show the incidences of involvement of chemicals also. Chemical warfare agents are one such example commonly employed by large group of people, mainly violent criminals who not only wants to create a terror or threat in the world but to cause war scale destruction. There are numerous of incidents reported from past showing the involvement of hazardous chemicals for committing crimes. Chemical Warfare Agents (CWA) are synthetic chemicals used in the warfare as weapons, which are highly toxic and lethal to the extent that can cause temporary incapacitation, permanent health damage and even death of the targets. Common examples of these agents are nerve agents, vesicants, incapacitating agents, blood agents, and riots control agents. These agents are variedly classified as per the above-mentioned categories depending onto the effects and adverse effects they poses on human health and on society. The rate of crime commission using these hazardous agents is very rapid, thus making it an issue of serious concern to take measures to prevent innocent individuals.
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Arefiev, S. V., A. Yu Bruslov, and A. V. Denisov. "Improvement of In-situ CO2 generation technology with compensation of chemicals concentration technological losses." Bulletin of Russian academy of natural sciences 24, no. 1 (2024): 47–56. http://dx.doi.org/10.52531/1682-1696-2024-24-1-47-56.
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The paper is about the enhanced oil recovery technology, based on in-situ carbon dioxide generation, after stoichiometric reaction between gas releasing chemical agent and gas producing one. Two ways of technology improvement are considered: for more uniform in-situ CO2 generation and for more safety when chemicals injection. Both ways require sufficient increase of buffer water, which divides reactive chemicals. Larger buffer water volumes, when being mixed with chemicals water solutions, sufficiently drop down chemical concentration. It also decreases CO2 concentration in water solution. Finally, chemicals and CO2 concentrations, for in- situ generation, decrease. To prevent such decrease, it is necessary to adjust, increase chemicals concentration, when preparing chemical water solution, so to consider further dilution in buffer water and to ensure required stoichiometric concentration in reservoir conditions. Increase of chemicals concentration can be also from decrease of chemicals solutions volumes. Quantitative estimates are given for increase of buffer water volumes, for impact of such increase on decrease of initial chemicals concentrations and decrease of CO2 concentration, in water solutions, as well. Working formulas are provided for calculations on buffer water volumes, adjusted, increased concentrations and decrease volumes of chemicals water solutions, at their preparation stage.
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Linderman, Robert G., and E. Anne Davis. "Evaluation of Chemical Agents for the Control of Phytophthora ramorum and Other Species of Phytophthora on Nursery Crops." Plant Health Progress 9, no. 1 (January 2008): 26. http://dx.doi.org/10.1094/php-2008-0211-01-rs.
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Phytophthora diseases occur frequently in nurseries, and the recent incidence of ramorum blight, caused by P. ramorum, on nursery crops has underscored the need for improved management strategies against all Phytophthora diseases. We evaluated several chemicals that target Oomycete pathogens, inoculating detached rhododendron or lilac leaves removed from plants previously treated with various chemicals, or chemically-treated leaves on intact plants. Results indicated that Subdue MAXX (drench or foliar application) was the most effective chemical in suppressing infections caused by all species of Phytophthora tested (P. ramorum, P. citricola, P. citrophthora, and P. nicotianae) except P. citrophthora; with P. ramorum, it was active for at least 6 weeks after spray application. More chemicals were effective when sporangial rather than mycelial plug inoculum of P. ramorum was used, including Aliette, Ranman, Stature DM, and Fenamidone. All chemicals tested were fungistatic, not fungicidal. These tests indicate that several materials inhibit infection by Phytophthora species, and that the detached leaf test is effective in evaluating efficacy of chemical agents for the suppression of Phytophthora pathogens from nurseries. Accepted for publication 10 November 2007. Published 11 February 2008.
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Villatte, Guillaume, Roger Erivan, Stéphane Descamps, Pierre Arque, Stéphane Boisgard, and Yohann Wittrant. "In vitro osteoblast activity is decreased by residues of chemicals used in the cleaning and viral inactivation process of bone allografts." PLOS ONE 17, no. 10 (October 10, 2022): e0275480. http://dx.doi.org/10.1371/journal.pone.0275480.
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Allograft bone tissue has a long history of use. There are two main ways of preserving allografts: by cold (freezing), or at room temperature after an additional cleaning treatment using chemicals. These chemicals are considered potentially harmful to humans. The aim of the study was (i) to assess the presence of chemical residues on processed bone allografts and (ii) to compare the in vitro biocompatibility of such allografts with that of frozen allografts. The presence of chemical residues on industrially chemically treated bone was assessed by high performance liquid chromatography (HPLC) after extraction. Biocompatibility analysis was performed on primary osteoblast cultures from Wistar rats grown on bone disks, either frozen (F-bone group) or treated with supercritical carbon dioxide with no added chemical (scCO2-bone group) or industrially treated with chemicals (CT-bone group). Cell viability (XTT) was measured after one week of culture. Osteoblastic differentiation was assessed after 1, 7 and 14 days of culture by measuring alkaline phosphatase (ALP) activity directly on the bone discs and indirectly on the cell mat in the vicinity of the bone discs. Residues of all the chemicals used were found in the CT-bone group. There was no significant difference in cell viability between the three bone groups. Direct and indirect ALP activities were significantly lower (−40% to −80%) in the CT-bone group after 7 and 14 days of culture (p < 0.05). Residues of chemical substances used in the cleaning of bone allografts cause an in vitro decrease in their biocompatibility. Tissue cleaning processes must be developed that limit or replace these chemicals to favor biocompatibility.
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Wang, Soon-Joo, and Seongyong Yoon. "Chemical Response Emergency Medical Information System in Chemical Disaster." Prehospital and Disaster Medicine 34, s1 (May 2019): s108. http://dx.doi.org/10.1017/s1049023x19002267.
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Introduction:There are many database sets and websites which provide chemical information, but they do not perform an adequate role for emergency medical support in a chemical disaster.Aim:To make the basis of a chemical emergency medical information system.Methods:We reviewed the database sets, mobile applications and websites in the world which provide chemical database and emergency medical response information from a chemical accident or disaster site to hospitals. Also, we examined chemical accident cases which developed during disasters. A chemical database set for emergency medical response was proposed and the algorithm for elicitation of chemicals suitable for emergency medical response and information providing. We performed a survey about chemical emergency medical information system to related personnel.Results:By four steps of elicitation of chemicals, the number of chemicals more than 100,000 was decreased to less than 1,000. The standard of steps includes accident preparedness, toxicity and circulating amount and expert consultation. Algorithm for elicitation of chemicals was made and 82% of related personnel supported the chemical emergency response algorithm. The emergency medical real-time consultation system for chemical disaster was placed under control of the call center.Discussion:When mass exposure by toxic chemicals occurs, the chemical emergency medical information system will be helpful for acute identification of chemicals, protection of related personnel and emergency medical response. Also, it can be possible to guide citizens immediately in case of a chemical disaster.
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Jeong, Michelle, Seth M. Noar, Dongyu Zhang, Jennifer R. Mendel, Robert P. Agans, Marcella H. Boynton, M. Justin Byron, et al. "Public Understanding of Cigarette Smoke Chemicals: Longitudinal Study of US Adults and Adolescents." Nicotine & Tobacco Research 22, no. 5 (April 10, 2019): 747–55. http://dx.doi.org/10.1093/ntr/ntz035.
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Abstract Introduction The US Food and Drug Administration has increased communication efforts that aim to raise public awareness of the harmful constituents (ie, chemicals) in cigarette smoke. We sought to investigate whether the public’s awareness of these chemicals has increased in light of such efforts. Methods Participants were national probability samples of 11 322 US adults and adolescents recruited in 2014–2015 (wave 1) and 2016–2017 (wave 2). Cross-sectional telephone surveys assessed awareness of 24 cigarette smoke chemicals at both timepoints. Results The proportion of US adults aware of cigarette smoke chemicals did not differ between waves 1 and 2 (25% and 26%, p = .19). In contrast, awareness of chemicals among adolescents fell from 28% to 22% (p < .001), mostly due to lower awareness of carbon monoxide, arsenic, benzene, and four other chemicals. Belief that most of the harmful chemicals in cigarette smoke come from burning the cigarette also fell from waves 1 to 2 (adults: 31% vs. 26%; adolescents: 47% vs. 41%, both ps < .05). Participants were more likely to be aware of cigarette smoke chemicals if they had been exposed to anti-smoking campaign advertisements (p < .05) or had previously sought chemical information (p < .05). Cigarette smoke chemical awareness did not differ between smokers and nonsmokers. Conclusion Awareness of cigarette smoke chemicals remains low and unchanged among adults and decreased somewhat among adolescents. The association of chemical awareness with information exposure via campaigns and information seeking behavior is promising. More concerted communication efforts may be needed to increase public awareness of cigarette smoke chemicals, which could potentially discourage smoking. Implications Awareness of the toxic chemicals in cigarette smoke may contribute to quitting. The US Food and Drug Administration is making efforts to increase public awareness of these chemicals. Two national surveys (2014–2017) found that chemical awareness was low among adults and adolescents. Although awareness did not change among adults, awareness among adolescents dropped over time. In addition, exposure to anti-smoking campaigns and chemical information seeking behavior were associated with higher awareness of chemicals in cigarette smoke. Campaigns and other efforts may be needed to increase awareness of cigarette smoke chemicals.
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Lin, Meihong, Xiaohui Liu, Jiaxin Chen, Jiguang Huang, and Lijuan Zhou. "Insecticidal Triterpenes in Meliaceae III: Plant Species, Molecules, and Activities in Munronia–Xylocarpus." International Journal of Molecular Sciences 25, no. 14 (July 17, 2024): 7818. http://dx.doi.org/10.3390/ijms25147818.
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Plants of the Meliaceae family have long attracted researchers’ interest due to their various insecticidal activities, with triterpenes being the main active ingredients. In this paper, we discuss 93 triterpenoids with insecticidal activity from 37 insecticidal plant species of 15 genera (Munronia, Neobeguea, Pseudocedrela, Nymania, Quivisia, Ruagea, Dysoxylum, Soymida, Lansium, Sandoricum, Walsura, Trichilia, Swietenia, Turraea, and Xylocarpus) in the family Meliaceae. Among these genera, Trichilia deserves further research, with twelve species possessing insecticidal activity. The 93 insecticidal molecules included 27 ring-seco limonoids (comprising 1 ring A-seco group chemical, 1 ring B-seco group chemical, 5 ring D-seco group chemicals, 14 rings A,B-seco group chemicals, 5 rings B,D-seco group chemicals, and 1 rings A,B,D-seco group chemical), 22 ring-intact limonoids (comprising 5 cedrelone-class chemicals, 6 trichilin-class chemicals, 7 havanensin-class chemicals, 2 azadirone-class chemicals, 1 vilasinin-class chemical, and 1 other chemical), 33 2,30-linkage chemicals (comprising 25 mexicanolide-class chemicals and 8 phragmalin-class chemicals), 3 1,n-linkage-group chemicals, 3 onoceranoid-type triterpenoids, 2 apotirucallane-type terpenoids, 2 kokosanolide-type tetranortriterpenoids, and 1 cycloartane triterpene. In particular, 59 molecules showed antifeedant activity, 30 molecules exhibited poisonous effects, and 9 molecules possessed growth regulatory activity. Particularly, khayasin, beddomei lactone, 3β,24,25-trihydroxycycloartane, humilinolides A–E and methyl-2-hydroxy-3β-isobutyroxy-1-oxomeliac-8(30)-enate showed excellent insecticidal activities, which were comparable to that of azadirachtin and thus deserved more attention. Moreover, it was noteworthy that various chemicals (such as 12α-diacetoxywalsuranolide, 11β,12α-diacetoxycedrelone, 1α,7α,12α-triacetoxy-4α-carbomethoxy-11β-hydroxy-14β,15β-epoxyhavanensin, and 11-epi-21-hydroxytoonacilide, etc.) from Turraea showed excellent insecticidal activity. Specially, the insecticidal activity of khayasin from Neobeguea against the coconut leaf beetle were similar to that of rotenone. Therefore, it was a promising candidate insecticide for the control of the coconut leaf beetle.
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Zulandt Schneider, R. A., and P. A. Moore. "Urine as a source of conspecific disturbance signals in the crayfish Procambarus clarkii." Journal of Experimental Biology 203, no. 4 (February 15, 2000): 765–71. http://dx.doi.org/10.1242/jeb.203.4.765.
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Chemical signals are an important aspect of ecological interactions in crustacean systems. Repellent chemical signals can be classified into three context-specific categories: chemicals released directly from a repellent stimulus (avoidance chemicals), chemicals released from damaged conspecifics (alarm chemicals) and chemicals released from stressed but undamaged conspecifics (stress chemicals). Our study examines the existence and putative source of the stress signals in crayfish. We hypothesize that Procambarus clarkii can recognize stressed individuals through chemical signals and also that the source of the signal that provides P. clarkii with information on the behavioral state of the sender is the urine. We collected urine and gill water from stressed and non-stressed animals, and chemicals from damaged conspecifics. Chemical cues were introduced into a test arena while several behavior patterns of P. clarkii were recorded. Stressed crayfish produce significantly more urine than non-stressed crayfish, and this urine caused crayfish to walk significantly faster and farther and away from the source of the signal. These results demonstrate that predator-stressed crayfish release urine that causes other crayfish to move away from the source of the signal. Responses to stress chemical signals may allow receiving organisms to avoid the fate of the signal sender.
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Kazerovska, Kristīne, Māris Kļaviņš, and Judīte Dipāne. "Approaches for Management of Chemical Substances: Challenges and Solutions." Proceedings of the Latvian Academy of Sciences. Section B. Natural, Exact, and Applied Sciences. 62, no. 1-2 (January 1, 2008): 1–8. http://dx.doi.org/10.2478/v10046-008-0008-z.
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Approaches for Management of Chemical Substances: Challenges and Solutions This article analyses the development of approaches for management of chemical substances in the frame of current reform of chemicals policy at the European Union level with regard to implementation of REACH Regulation No. 1907/2006. REACH is considered as an integrated approach to the control of the production, import and use of chemicals in the European Union, especially of those chemical substances with the most hazardous properties. The new approach covers both the strengths of old and new chemical policies, also requires revision of existing understandings about chemical production, import and use: responsibilities of all involved actors, the chemicals supply chain, and information flow within chemicals supply chain.
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Wheeler, David C., Salem Rustom, Matthew Carli, Todd P. Whitehead, Mary H. Ward, and Catherine Metayer. "Assessment of Grouped Weighted Quantile Sum Regression for Modeling Chemical Mixtures and Cancer Risk." International Journal of Environmental Research and Public Health 18, no. 2 (January 9, 2021): 504. http://dx.doi.org/10.3390/ijerph18020504.
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Individuals are exposed to a large number of diverse environmental chemicals simultaneously and the evaluation of multiple chemical exposures is important for identifying cancer risk factors. The measurement of a large number of chemicals (the exposome) in epidemiologic studies is allowing for a more comprehensive assessment of cancer risk factors than was done in earlier studies that focused on only a few chemicals. Empirical evidence from epidemiologic studies shows that chemicals from different chemical classes have different magnitudes and directions of association with cancers. Given increasing data availability, there is a need for the development and assessment of statistical methods to model environmental cancer risk that considers a large number of diverse chemicals with different effects for different chemical classes. The method of grouped weighted quantile sum (GWQS) regression allows for multiple groups of chemicals to be considered in the model such that different magnitudes and directions of associations are possible for each group of chemicals. In this paper, we assessed the ability of GWQS regression to estimate exposure effects for multiple chemical groups and correctly identify important chemicals in each group using a simulation study. We compared the performance of GWQS regression with WQS regression, the least absolute shrinkage and selection operator (lasso), and the group lasso in estimating exposure effects and identifying important chemicals. The simulation study results demonstrate that GWQS is an effective method for modeling exposure to multiple groups of chemicals and compares favorably with other methods used in mixture analysis. As an application, we used GWQS regression in the California Childhood Leukemia Study (CCLS), a population-based case-control study of childhood leukemia in California to estimate exposure effects for many chemical classes while also adjusting for demographic factors. The CCLS analysis found evidence of a positive association between exposure to the herbicide dacthal and an increased risk of childhood leukemia.
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Wheeler, David C., Salem Rustom, Matthew Carli, Todd P. Whitehead, Mary H. Ward, and Catherine Metayer. "Assessment of Grouped Weighted Quantile Sum Regression for Modeling Chemical Mixtures and Cancer Risk." International Journal of Environmental Research and Public Health 18, no. 2 (January 9, 2021): 504. http://dx.doi.org/10.3390/ijerph18020504.
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Individuals are exposed to a large number of diverse environmental chemicals simultaneously and the evaluation of multiple chemical exposures is important for identifying cancer risk factors. The measurement of a large number of chemicals (the exposome) in epidemiologic studies is allowing for a more comprehensive assessment of cancer risk factors than was done in earlier studies that focused on only a few chemicals. Empirical evidence from epidemiologic studies shows that chemicals from different chemical classes have different magnitudes and directions of association with cancers. Given increasing data availability, there is a need for the development and assessment of statistical methods to model environmental cancer risk that considers a large number of diverse chemicals with different effects for different chemical classes. The method of grouped weighted quantile sum (GWQS) regression allows for multiple groups of chemicals to be considered in the model such that different magnitudes and directions of associations are possible for each group of chemicals. In this paper, we assessed the ability of GWQS regression to estimate exposure effects for multiple chemical groups and correctly identify important chemicals in each group using a simulation study. We compared the performance of GWQS regression with WQS regression, the least absolute shrinkage and selection operator (lasso), and the group lasso in estimating exposure effects and identifying important chemicals. The simulation study results demonstrate that GWQS is an effective method for modeling exposure to multiple groups of chemicals and compares favorably with other methods used in mixture analysis. As an application, we used GWQS regression in the California Childhood Leukemia Study (CCLS), a population-based case-control study of childhood leukemia in California to estimate exposure effects for many chemical classes while also adjusting for demographic factors. The CCLS analysis found evidence of a positive association between exposure to the herbicide dacthal and an increased risk of childhood leukemia.
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Geiser, Ken. "Redesigning Chemicals Policy: A Very Different Approach." NEW SOLUTIONS: A Journal of Environmental and Occupational Health Policy 21, no. 3 (October 14, 2011): 329–44. http://dx.doi.org/10.2190/ns.21.3.c.
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The chemical policies of the 1970s were limited by the assumptions that lie at their foundation and focused narrowly on only the most hazardous chemicals. The effective management of chemicals requires policies that focus on the entire body of chemicals and the production systems that make them. The future will require comprehensive chemicals policies that work within a systems framework to phase out the most hazardous chemicals, progressively transition away from the remaining chemicals of concern by substituting safer chemicals and technologies, and invest heavily in a new generation of safer and more sustainable chemicals.
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Hawthorne, Christopher, David A. Simpson, Barry Devereux, and Guillermo López-Campos. "Phexpo: a package for bidirectional enrichment analysis of phenotypes and chemicals." JAMIA Open 3, no. 2 (July 1, 2020): 173–77. http://dx.doi.org/10.1093/jamiaopen/ooaa023.
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Abstract Phenotypes are the result of the complex interplay between environmental and genetic factors. To better understand the interactions between chemical compounds and human phenotypes, and further exposome research we have developed “phexpo,” a tool to perform and explore bidirectional chemical and phenotype interactions using enrichment analyses. Phexpo utilizes gene annotations from 2 curated public repositories, the Comparative Toxicogenomics Database and the Human Phenotype Ontology. We have applied phexpo in 3 case studies linking: (1) individual chemicals (a drug, warfarin, and an industrial chemical, chloroform) with phenotypes, (2) individual phenotypes (left ventricular dysfunction) with chemicals, and (3) multiple phenotypes (covering polycystic ovary syndrome) with chemicals. The results of these analyses demonstrated successful identification of relevant chemicals or phenotypes supported by bibliographic references. The phexpo R package (https://github.com/GHLCLab/phexpo) provides a new bidirectional analyses approach covering relationships from chemicals to phenotypes and from phenotypes to chemicals.
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Wang, Bing Qiang. "The Causes and Prevention of Chemicals Pollution." Advanced Materials Research 1092-1093 (March 2015): 943–46. http://dx.doi.org/10.4028/www.scientific.net/amr.1092-1093.943.
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Various chemicals increase greatly and new chemicals are constantly emerging with the rapid development of world chemical industry. People make full use of chemicals and produce a large number of chemical waste including toxic and harmful substances. Because the uncontrolled discharge, the environment is worsening. It is the major problem for people to understand the causes and harm of chemical pollution and strengthen environmental protection.
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Jarema, Kimberly A., Deborah L. Hunter, Bridgett N. Hill, Jeanene K. Olin, Katy N. Britton, Matthew R. Waalkes, and Stephanie Padilla. "Developmental Neurotoxicity and Behavioral Screening in Larval Zebrafish with a Comparison to Other Published Results." Toxics 10, no. 5 (May 17, 2022): 256. http://dx.doi.org/10.3390/toxics10050256.
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With the abundance of chemicals in the environment that could potentially cause neurodevelopmental deficits, there is a need for rapid testing and chemical screening assays. This study evaluated the developmental toxicity and behavioral effects of 61 chemicals in zebrafish (Danio rerio) larvae using a behavioral Light/Dark assay. Larvae (n = 16–24 per concentration) were exposed to each chemical (0.0001–120 μM) during development and locomotor activity was assessed. Approximately half of the chemicals (n = 30) did not show any gross developmental toxicity (i.e., mortality, dysmorphology or non-hatching) at the highest concentration tested. Twelve of the 31 chemicals that did elicit developmental toxicity were toxic at the highest concentration only, and thirteen chemicals were developmentally toxic at concentrations of 10 µM or lower. Eleven chemicals caused behavioral effects; four chemicals (6-aminonicotinamide, cyclophosphamide, paraquat, phenobarbital) altered behavior in the absence of developmental toxicity. In addition to screening a library of chemicals for developmental neurotoxicity, we also compared our findings with previously published results for those chemicals. Our comparison revealed a general lack of standardized reporting of experimental details, and it also helped identify some chemicals that appear to be consistent positives and negatives across multiple laboratories.
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Kong, Chui-Hua, Zheng Li, Feng-Li Li, Xin-Xin Xia, and Peng Wang. "Chemically Mediated Plant–Plant Interactions: Allelopathy and Allelobiosis." Plants 13, no. 5 (February 24, 2024): 626. http://dx.doi.org/10.3390/plants13050626.
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Plant–plant interactions are a central driver for plant coexistence and community assembly. Chemically mediated plant–plant interactions are represented by allelopathy and allelobiosis. Both allelopathy and allelobiosis are achieved through specialized metabolites (allelochemicals or signaling chemicals) produced and released from neighboring plants. Allelopathy exerts mostly negative effects on the establishment and growth of neighboring plants by allelochemicals, while allelobiosis provides plant neighbor detection and identity recognition mediated by signaling chemicals. Therefore, plants can chemically affect the performance of neighboring plants through the allelopathy and allelobiosis that frequently occur in plant–plant intra-specific and inter-specific interactions. Allelopathy and allelobiosis are two probably inseparable processes that occur together in plant–plant chemical interactions. Here, we comprehensively review allelopathy and allelobiosis in plant–plant interactions, including allelopathy and allelochemicals and their application for sustainable agriculture and forestry, allelobiosis and plant identity recognition, chemically mediated root–soil interactions and plant–soil feedback, and biosynthesis and the molecular mechanisms of allelochemicals and signaling chemicals. Altogether, these efforts provide the recent advancements in the wide field of allelopathy and allelobiosis, and new insights into the chemically mediated plant–plant interactions.
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Shin, Moon-Sik, Yi Yoon, Seungmin Kang, and Janghyeon Cha. "Analysis of the Potential Use of Schedule 1 Chemicals and Toxic Industrial Substances in Chemical Terrorism." Korean Association for Terrorism Studies 16, no. 3 (September 30, 2023): 129–53. http://dx.doi.org/10.46350/kats.2023.16.3.129.
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In this study, we analyzed chemical substances that could be used in chemical terrorism for the purpose of mass destruction, social disruption and assassination, and suggested ways to effectively manage these chemicals. The analysis focused on toxic industrial substance which are suggested by accident preparation substances from regulations and literature, and schedule 1 chemicals which actually used in chemical terrorism recently. The analysis was conducted based on ease of acquisition, transportation, and dispersal, which can vary depending on the physical, chemical properties and toxicity of the substances. The review concluded that the schedule 1 chemical is more likely to be utilized for chemical terrorism compared to industrial toxic substances. Unlike industrial toxic substance, schedule 1 chemical can be obtained through synthesis or smuggling from abroad. They possess high toxicity enough to achieve object with small quantities, so that it has advantages of secretly transportation and dispersal to that target location or individuals. This analysis is supported by recent chemical terrorism cases. To prevent terrorists from acquiring the schedule 1 chemicals identified as potential candidates for chemical terrorism, effective management and supervision of various chemicals that can be used for the synthesis of schedule 1 chemical is crucial. In this regard, it is essential to thoroughly monitor and analyze the chemicals purchased by consumers to determine their potential for synthesizing these category of chemicals. To achieve this, we propose the establishment and utilization of an artificial intelligence-based system.
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Raevsky, O. A., E. A. Liplavskaya, A. P. Worth, and V. U. Grigorev. "Acute intravenous toxicity to mice calculations on the basis local regression models in superoverlapping clusters (LRMSC)." Biomeditsinskaya Khimiya 58, no. 5 (2012): 489–500. http://dx.doi.org/10.18097/pbmc20125805489.
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Modeling of quantitative structure - activity relationships between physicochemical descriptors of organic chemicals and their acute intravenous toxicity in mice have been presented. This approach includes three steps: structure-similarity chemicals selection for every chemical-of-interest (clusterization); construction of quantitative structure - toxicity models for every cluster (without including of chemical-of-interest); application of obtained QSAR equations for chemical-of-interest toxicity estimation. This approach has been applied for acute intravenous toxicity calculations of 10241 organic chemicals. For 7759 chemicals which has enough quantity of structural neighbours with the Tanimoto index (Tc) on the level 0.30 and over, a standard deviation of calculation vs. experimental log(1/LD50) values is equal to 0.51 at the estimation of experimental determination on the level 0.50. The results of calculations isn't so good for remain chemicals (~24%). It is connect with absence of sufficient number of structure similarity neighbours. It's assumed this QSAR approach can be useful for activity and toxicity prediction of chemicals large sets.
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Hantak, Maggie M., Daniel J. Paluh, and Ralph A. Saporito. "Bufadienolide and alkaloid-based chemical defences in two different species of neotropical anurans are equally effective against the same arthropod predators." Journal of Tropical Ecology 32, no. 2 (March 2016): 165–69. http://dx.doi.org/10.1017/s0266467416000055.
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Abstract:Defensive chemicals in anuran skin secretions function in protection against potential predators. Although studies have demonstrated that particular chemicals are effective against certain predators, very little is known about how different chemicals from different species function against the same predators. Understanding how different chemicals function as a defence against similar predators is fundamental to the ecology and evolution of chemical defences in frogs. In the present study, the defensive function of bufadienolide-based defences in adult Rhaebo haematiticus (Bufonidae) were compared with alkaloid-based defences in adult and juvenile Dendrobates auratus (Dendrobatidae) against the same predators. Most bufonids contain synthesized bufadienolides, whereas dendrobatids contain dietary-derived alkaloids. Predation trials were performed with two potential invertebrate predators, Paraponera clavata (bullet ant) and Cupiennius coccineus (ctenid spider), to determine how these predators respond to two different types of frog chemical defence. The non-chemically defended frog Craugastor fitzingeri served as a control in all predation trials. Our results suggest that bufadienolide defences of R. haematiticus and alkaloid defences of D. auratus are equally effective towards bullet ant and ctenid spider predators. The similar avoidance and cleaning behaviours exhibited by these ants and spiders after contact with bufadienolides and alkaloids suggest that both types of defence are unpalatable to these arthropod predators.
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Zhao, Jumin, Fangfang Xue, and Deng-ao Li. "Intelligent Management of Chemical Warehouses with RFID Systems." Sensors 20, no. 1 (December 24, 2019): 123. http://dx.doi.org/10.3390/s20010123.
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At present, most chemical warehouses rely on human management, which is a time-consuming and laborious process. Therefore, it is very meaningful to use radio frequency identification (RFID) systems for the intelligent management of chemicals. Detecting the remaining amount of chemicals is an important process in the management of a chemical warehouse. It helps managers find the chemicals that are going to run out and replenish them in time. However, in a traditional chemical warehouse, managers usually inspect each chemical on the shelf in turn manually, which is a waste of time and labor. Although some solutions using RFID technology have been proposed, they are expensive and difficult to deploy in a real environment. In order to solve this problem, we propose an intelligent system called the RF-Detector in this paper, which combines robotics and RFID technology. An RFID reader and an antenna are installed on the robot, which achieves automatic scanning of the chemicals. The RF-Detector can achieve two functions: One function is to detect the remaining amount of chemicals using the changes in received signal strength indication (RSSI) and read rate, and the other is to locate chemicals using the phase curve, so that managers can quickly find the chemicals with an insufficient amount remaining. In this paper we implement the RF-Detector and evaluate its performance. The experimental results show that the RF-Detector achieves about 93% detection accuracy and 92% positioning accuracy for chemicals.
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Grant, Donald, Dan Smith, Peter Palm, Faa-Ching Wang, Danny Charest, Juan Campaneria, Loh Wai, et al. "Design and Certification of High Purity Delivery Systems for Semiconductor Wafer Cleaning Chemicals." Journal of the IEST 37, no. 6 (November 1, 1994): 32–40. http://dx.doi.org/10.17764/jiet.2.37.6.r62726744v254354.
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The wafer cleaning procedures used in new semiconductor manufacturing facilities require extremely high purity chemicals. Delivering chemicals of this quality requires careful management of the chemicals from their manufacturing site to the points of use (POUs) within the wafer fabrication facility (fab). Chemical management includes proper chemical production, transportation to the wafer fab and design and operation of the chemical delivery system within the fab. This paper describes the technology used to supply 15 different types of chemicals to more than 60 POUs in the TECH Semiconductor wafer fab in Singapore. The certification and continuous monitoring program confirms sub-ppb chemical delivery with particle concentrations of < 3 particles/ml at ≥ 0.2 μm. Several challenges associated with the initial design and installation of the chemical delivery system and their resolution are also described.
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Carberry, Celeste K., Toby Turla, Lauren E. Koval, Hadley Hartwell, Rebecca C. Fry, and Julia E. Rager. "Chemical Mixtures in Household Environments: In Silico Predictions and In Vitro Testing of Potential Joint Action on PPARγ in Human Liver Cells." Toxics 10, no. 5 (April 19, 2022): 199. http://dx.doi.org/10.3390/toxics10050199.
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There are thousands of chemicals that humans can be exposed to in their everyday environments, the majority of which are currently understudied and lack substantial testing for potential exposure and toxicity. This study aimed to implement in silico methods to characterize the chemicals that co-occur across chemical and product uses in our everyday household environments that also target a common molecular mediator, thus representing understudied mixtures that may exacerbate toxicity in humans. To detail, the Chemical and Products Database (CPDat) was queried to identify which chemicals co-occur across common exposure sources. Chemicals were preselected to include those that target an important mediator of cell health and toxicity, the peroxisome proliferator activated receptor gamma (PPARγ), in liver cells that were identified through query of the ToxCast/Tox21 database. These co-occurring chemicals were thus hypothesized to exert potential joint effects on PPARγ. To test this hypothesis, five commonly co-occurring chemicals (namely, benzyl cinnamate, butyl paraben, decanoic acid, eugenol, and sodium dodecyl sulfate) were tested individually and in combination for changes in the expression of PPARγ and its downstream target, insulin receptor (INSR), in human liver HepG2 cells. Results showed that these likely co-occurring chemicals in household environments increased both PPARγ and INSR expression more significantly when the exposures occurred as mixtures vs. as individual chemicals. Future studies will evaluate such chemical combinations across more doses, allowing for further quantification of the types of joint action while leveraging this method of chemical combination prioritization. This study demonstrates the utility of in silico-based methods to identify chemicals that co-occur in the environment for mixtures toxicity testing and highlights relationships between understudied chemicals and changes in PPARγ-associated signaling.
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Fox, Jennifer E. "Chemical communication threatened by endocrine-disrupting chemicals." Environmental Health Perspectives 112, no. 6 (May 2004): 648–53. http://dx.doi.org/10.1289/ehp.6455.
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Barnett, Michael P. "Chemical calculations and chemicals that might calculate." International Journal of Quantum Chemistry 109, no. 8 (December 23, 2008): 1640–57. http://dx.doi.org/10.1002/qua.21969.
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Terziev, Venelin, and Stoyanka Petkova - Georgieva. "ORGANO-PHOSPHONATE, ORGANO-HALOGENATTED, CYANIDES AND ARSENIC TOXIC IMPACT ON THE HUMAN HEALTH CARE CONDITION." vol 5 issue 15 5, no. 15 (December 28, 2019): 1357–62. http://dx.doi.org/10.18769/ijasos.592106.
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This research describes the toxic impact on the health condition of living nature because of the inevitable use of toxic chemical compounds (TCC) and toxic industrial chemicals (TICs). To reach this aim, the following objectives were established: to define the large-scale industrial chemicals from the Schedules of the Chemical weapon convention; to investigate the role of each chemical in production process; to determine the current amounts of substances used in the process and find the alternatives for their replacement. The research was conducted on the base of only open-source literature. The general description of the chemicals use was found in electronic and paper encyclopaedias, more deep understanding – received after study of scientific and technological periodics and patents from electronic bases. The content in this review is focused on the toxic impact of the organo – phosphonate, organo – halogenated, cyanides and arsenic toxic chemicals compounds. Keywords: impact, human health care, toxis chemical compounds, toxic industial chemicals.
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Zoeller, Thomas. "Environmental chemicals targeting thyroid." HORMONES 9, no. 1 (January 15, 2010): 28–40. http://dx.doi.org/10.14310/horm.2002.1250.
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Luo, Yan, and Yi Li. "Control quantity or toxicity of textile chemicals? A case study of denim jeans in the warp-dyeing phase." Textile Research Journal 91, no. 15-16 (February 8, 2021): 1900–1906. http://dx.doi.org/10.1177/0040517521993488.
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The extensive use and discharge of chemicals is one of the main factors leading to serious environmental pollution in the textiles and apparel industry. The chemical footprint (ChF) is a toxicity-based chemical management method that is used to quantitatively evaluate the potential toxic effects of chemical pollutants discharged during the production of textiles and apparel products on human health and environmental safety. Compared with the traditional quantity-based method, this method needs to simulate the entire process of chemicals from discharge to impact, involving a series of steps of fate, exposure and effect, which greatly increases the difficulty of modeling. A scientific question is whether it is worth spending so much effort to quantify the toxicity of chemicals. Taking the warp-dyeing phase of denim jeans as an example, this paper calculated the ChFs for both human and ecological toxicities of textile chemicals based on the USEtox model, and compared them with the values of discharge quantities. The results reveal that there is a certain inconsistency between the discharge quantity and toxicity of chemical substances. Relying solely on the amount of chemicals discharged can sometimes lead to misjudgments, emphasizing the importance of controlling the toxicity of chemicals.
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Yang, Li. "Research on Measures to Strengthen Environmental Risk Management of Chemicals in Jiangsu Province." Advanced Materials Research 955-959 (June 2014): 1670–75. http://dx.doi.org/10.4028/www.scientific.net/amr.955-959.1670.
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The problem of environment pollution and risk of chemicals is extremely serious. As an important chemical province, Jiangsu Province shall pay much attention to strengthening environmental management of chemicals. The paper analyzes the current management of chemicals at home and abroad and difficulties faced by environmental management of chemicals. According to the actual situation in Jiangsu Province, this paper offers some measures and suggestions for strengthening environmental management of chemicals.
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Chae, Yooeun, Lia Kim, Rongxue Cui, Jieun Lee, and Youn-Joo An. "Development of Methodology for Vulnerability Assessment of Chemical Accident in Terrestrial Ecosystem: (2) Focusing on the Herbs." Journal of Korean Society of Environmental Engineers 42, no. 12 (December 31, 2020): 610–22. http://dx.doi.org/10.4491/ksee.2020.42.12.610.
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Objective:As the industry rapidly develops in modern society, the use of chemicals increases and people and various organism living in terrestrial environments are exposed to these chemicals in large quantities. Chemical accidents frequently occur around the world, and these accidents could cause fatal damage to the terrestrial ecosystem. When the terrestrial ecosystem is exposed to highly toxic chemicals, soil functions as well as living organisms in the terrestrial ecosystem could be severely damaged. Countermeasures against chemical accidents and chemicals are required to prevent such damage and for this purpose, systematic vulnerability assessment techniques should be developed to prepare terrestrial ecosystem management for chemical accidents. For this purpose, this study is conducted to develop chemical vulnerability assessment techniques based on biological characteristics of plants.Method:First, we selected 215 species among herb plants according to the domestic distribution and establish various vulnerability indicators that can be evaluated according to the exposure and recovery categories.Results and Discussion:As a result of vulnerability scoring for 215 herbs species, the most vulnerable species were Humulus japonicus, Linum usitatissimum, Psilotum nudum, Trigonotis peduncularis, and Lamium amplexicaule. The least vulnerable species were Miscanthus sinensis, Dactylis glomerata, Spodiopogon sibiricus, and Polygonum filiforme.Conclusions:Terrestrial ecosystem is a main stage of human activity, so there is a high risk of chemical accidents as a large amount of chemicals are used. By utilizing this terrestrial ecosystem vulnerability assessment proposed in this study, we can prioritize the vulnerability of chemicals on the terrestrial ecosystem and use this technique to manage chemical accidents and chemicals and prepare countermeasures.
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Slunge, Daniel, and Francisco Alpizar. "Market-Based Instruments for Managing Hazardous Chemicals: A Review of the Literature and Future Research Agenda." Sustainability 11, no. 16 (August 11, 2019): 4344. http://dx.doi.org/10.3390/su11164344.
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We take stock of the lessons learned from using market-based instruments in chemicals management and discuss the potential for increased use of risk-based taxation in the management of pesticides and other hazardous chemicals. Many chemical substances cause significant diffuse emissions when emitted over wide areas at individually low concentrations. These emissions are typically very difficult and costly to control. The targeted chemical may exist in many products as well as in a wide variety of end uses. However, the current regulatory instruments used are primarily bans or quantitative restrictions, which are applied to individual chemicals and for very specific uses. Policy makers in the area of chemicals management have focused almost solely on chemicals with a very steep marginal damage cost curve, leading to low use of price regulations. The growing concerns about cumulative effects and combination effects from low dose exposure from multiple chemicals can motivate a broader use of market-based instruments in chemicals management.
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Wang, Z., S. Zheng, H. H. Wang, and S. Liang. "Determinants of agricultural chemical price in China’s export-oriented vegetable production area." Agricultural Economics (Zemědělská ekonomika) 56, No. 1 (January 29, 2010): 32–42. http://dx.doi.org/10.17221/1/2009-agricecon.
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Agricultural chemicals may have an adverse impact on environment and food safety. The demand prices of such chemicals reveal farmers’ willingness to pay and their preferences. This article examines the determinants of the agricultural chemicals price in the export-oriented vegetable production area, Anqiu, Shandong Province, applying the Hedonic Price Model based on the spatial econometric technique to analyze the price. We find that the agricultural chemicals with a different shape and function have different equilibrium prices, and the chemical attributes of permeability, rainfastness, being a substitute of the highly poisonous chemical, having a zero residue, and the internal absorption can all influence the equilibrium prices remarkably. We also find that the prices of biological and non-pollution agricultural chemicals might not be higher than the ordinary agricultural chemicals with the same characteristics. These findings do not show a good sign to the new agricultural chemicals promotion and environmental protection, and should be brought to the government’s attention.
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Haleem, Azhar M. "Semi-Quantitative Risk Assessment in the Chemical Stores of the University of Technology, Baghdad, Iraq." Engineering and Technology Journal 38, no. 3B (December 25, 2020): 204–11. http://dx.doi.org/10.30684/etj.v38i3b.894.
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Chemicals are used daily at the university, by its students or staff so it’s necessary to develop a chemical management system to protect their workers and students from accidents caused by exposure to chemicals of various forms, the present study explains the methodology for assessing the health effects and risks of exposure to chemicals in the chemical stores of University of Technology (UOT) by using semi- quantitative risk assessment technique depends on a descriptive analytical approach, by collecting the requested information for seven main stores within the university by questionnaire form included inquiries about personal information about employees, level of education and years of experience, it also included inquiries about chemical stores and storage volumes, at first identified the exposed people, detected high demand chemicals, subsequently identified the chemical hazardous factors, exposure rate and risk level of each substance, ultimately the risk was identified for 41 chemicals among them four strong acids, hydrochloric, sulfuric, nitric and chromic with high exposure rate benzene and xylene that have high risk level, from results of chemical survey can be conclude 71% of the total chemicals classified as high to moderate risk level, so the study recommends the continuity of the periodic assessment of chemical hazards within the stores of university, include laboratories in assessment procedures, providing of personal safety equipment.
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Haleem, Azhar M. "Semi-Quantitative Risk Assessment in the Chemical Stores of the University of Technology, Baghdad, Iraq." Engineering and Technology Journal 38, no. 3B (December 25, 2020): 204–11. http://dx.doi.org/10.30684/etj.v38i3b.894.
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Chemicals are used daily at the university, by its students or staff so it’s necessary to develop a chemical management system to protect their workers and students from accidents caused by exposure to chemicals of various forms, the present study explains the methodology for assessing the health effects and risks of exposure to chemicals in the chemical stores of University of Technology (UOT) by using semi- quantitative risk assessment technique depends on a descriptive analytical approach, by collecting the requested information for seven main stores within the university by questionnaire form included inquiries about personal information about employees, level of education and years of experience, it also included inquiries about chemical stores and storage volumes, at first identified the exposed people, detected high demand chemicals, subsequently identified the chemical hazardous factors, exposure rate and risk level of each substance, ultimately the risk was identified for 41 chemicals among them four strong acids, hydrochloric, sulfuric, nitric and chromic with high exposure rate benzene and xylene that have high risk level, from results of chemical survey can be conclude 71% of the total chemicals classified as high to moderate risk level, so the study recommends the continuity of the periodic assessment of chemical hazards within the stores of university, include laboratories in assessment procedures, providing of personal safety equipment.
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Jiang, Zhanpeng, Rui Xu, and Changchun Dong. "Identification of Chemical Toxicity Using Ontology Information of Chemicals." Computational and Mathematical Methods in Medicine 2015 (2015): 1–5. http://dx.doi.org/10.1155/2015/246374.
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With the advance of the combinatorial chemistry, a large number of synthetic compounds have surged. However, we have limited knowledge about them. On the other hand, the speed of designing new drugs is very slow. One of the key causes is the unacceptable toxicities of chemicals. If one can correctly identify the toxicity of chemicals, the unsuitable chemicals can be discarded in early stage, thereby accelerating the study of new drugs and reducing the R&D costs. In this study, a new prediction method was built for identification of chemical toxicities, which was based on ontology information of chemicals. By comparing to a previous method, our method is quite effective. We hope that the proposed method may give new insights to study chemical toxicity and other attributes of chemicals.
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Borrett, VT, RJ Mathews, and ER Mattsson. "Verification of the Chemical Weapons Convention: Mass Spectrometry of Alkyl Methylphosphonofluoridates." Australian Journal of Chemistry 47, no. 11 (1994): 2065. http://dx.doi.org/10.1071/ch9942065.
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Under the provisions of the United Nations Chemical Weapons Convention (CWC), certain parts of chemical industry will be monitored to verify compliance with the Convention. This will include analysis of samples from industrial sites to check for the presence or absence of chemical warfare related compounds. One of the problems in screening the chemicals to be monitored under the CWC is that certain classes of chemical warfare agents are represented as families of chemicals, with many of the individual chemicals having no analytical data available. One example is the alkyl methylphosphonofluoridate family with an alkyl ester substituent from CH3 to C10H21. In this work, the mass spectra of 60 alkyl methylphosphonofluoridate family members have been studied to enable the development of rapid on-site screening methods for this family of chemicals.
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Blum, D. J. W., and R. E. Speece. "The Toxicity of Organic Chemicals to Treatment Processes." Water Science and Technology 25, no. 3 (February 1, 1992): 23–31. http://dx.doi.org/10.2166/wst.1992.0073.
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The IC50 concentration was determined for a common set of narcotic chemicals to three classes of environmental organisms - aerobic heterotrophs, methanogens and Nitrosomonas as well as to MicrotoxR. The toxicity was well modeled using the linear solvation energy relationship which incorporates molecular volume, polarity/polarizability, hydrogen bond donor acidity and hydrogen bond donor basicity. Chemical characteristics which contribute to a chemical's toxicity are discussed. The relative toxicity to these different classes of environmental microorganisms is discussed and the implications to biological treatment process stability are considered.
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Goodson, William H., Leroy Lowe, Michael Gilbertson, and David O. Carpenter. "Testing the low dose mixtures hypothesis from the Halifax project." Reviews on Environmental Health 35, no. 4 (November 18, 2020): 333–57. http://dx.doi.org/10.1515/reveh-2020-0033.
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AbstractIn 2013, 60 scientists, representing a larger group of 174 scientists from 26 nations, met in Halifax, Nova Scotia to consider whether – using published research – it was logical to anticipate that a mixture of chemicals, each thought to be non-carcinogenic, might act together in that mixture as a virtual carcinogen. The group identified 89 such chemicals, each one affecting one or more Hallmark(s) – collectively covering all Hallmarks of Cancer – confirming the possibility that a chemical mixture could induce all the Hallmarks and function as a virtual carcinogen, thereby supporting the concern that chemical safety research that does not evaluate mixtures, is incomplete. Based on these observations, the Halifax Project developed the Low-Dose Carcinogenesis Hypothesis which posits “…that low-dose exposures to [mixtures of] disruptive chemicals that are not individually carcinogenic may be capable of instigating and/or enabling carcinogenesis.” Although testing all possible combinations of over 80,000 chemicals of commerce would be impractical, prudence requires designing a methodology to test whether low-dose chemical mixtures might be carcinogenic. As an initial step toward testing this hypothesis, we conducted a mini review of published empirical observations of biological exposures to chemical mixtures to assess what empirical data exists on which to base future research. We reviewed studies on chemical mixtures with the criteria that the studies reported both different concentrations of chemicals and mixtures composed of different chemicals. We found a paucity of research on this important question. The majority of studies reported hormone related processes and used chemical concentrations selected to facilitate studying how mixtures behave in experiments that were often removed from clinical relevance, i.e., chemicals were not studied at human-relevant concentrations. New research programs must be envisioned to enable study of how mixtures of small doses of chemicals affect human health, starting, when at all possible, from non-malignant specimens when studies are done in vitro. This research should use human relevant concentrations of chemicals, expand research beyond the historic focus on endocrine endpoints and endocrine related cancers, and specifically seek effects that arise uniquely from exposure to chemical mixtures at human-relevant concentrations.
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Jou, C. Jerry, Jay P. Farber, Chao Qin, and Robert D. Foreman. "Afferent pathways for cardiac-somatic motor reflexes in rats." American Journal of Physiology-Regulatory, Integrative and Comparative Physiology 281, no. 6 (December 1, 2001): R2096—R2102. http://dx.doi.org/10.1152/ajpregu.2001.281.6.r2096.
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The present study used a rat model in which algogenic chemicals were infused into the pericardial sac to evoke spasmlike contractions in paraspinal muscles. The following techniques were used to study the roles of sympathetic (SCA) and vagal cardiac afferents (VCA) in electromyographic (EMG) responses to pericardial algogenic chemicals: chemical stimulation, electrical stimulation, and nerve transection. Activation with bradykinin ( n = 46) produced a significantly higher peak response than infusion of an algogenic mixture ( n = 53) containing chemicals that also activate VCA. Electrical stimulation of SCA produced bilateral EMG activities (7 of 7). Electrical stimulation of VCA did not evoke EMG activity but inhibited the chemically evoked EMG response (12 of 12). The chemically evoked response was decreased after transection of the left sympathetic chain ( n = 22) and was increased after bilateral vagotomy ( n = 19). These results suggest an excitatory and inhibitory role for SCA and VCA, respectively. Therefore, in addition to spinothalamic convergence of somatic and visceral afferents, activation of SCA to generate spasmlike muscle contractions could account in part for anginal pain, and VCA activation could attenuate this effect.