Chemical Exposure Risk Research Articles

Examining the relationship between health literacy and pesticide protective behaviors among farmers in Thailand

Background The use of chemical pesticides without proper health literacy (HL) and necessary pesticide protective behaviors (PPB) can result in adverse effects on human health. Methods This study aims to determine if there is a correlation between HL and PPB among farmers in the Nakhon Ratchasima province, using a random sample of 464 farmers. Structured interviews consisted of three parts: 1. General information, 2. Health literacy (including knowledge, understanding, and other sub-aspects), and 3. Protective behaviors against chemical exposure. Each part of the questionnaire had a reliability index of 0.60 or higher. The reliability of the 2nd and 3rd parts of the questionnaire were as follows: sub-sections of part 2 had a Kuder-Richardson (KR-20) coefficient of 0.79 and Cronbach’s alpha (α) coefficient of 0.85-0.86, while part 3 had an α of 0.88. Risk of chemical exposure was assessed using a Cholinesterase Reactive Paper test administered by a finger-prick blood test. Data was analyzed using the Spearman correlation and binary logistic regression. The study was reviewed by the Human Research Ethics Committee with the approval date: August 9, 2021, and expiry date: August 9, 2022. Results Most participants had moderate levels of overall HL (48.8%) and PPB (44.6%). There was a statistically significant positive correlation between HL and PPB (rs(478) = 0.70, p<.005). Logistic regression analysis demonstrated that HL had a statistically significant positive association with PPB (p<.001, OR = 6.57, 95% CI 3.95, 10.94) and was associated with blood cholinesterase levels. Conclusions These findings highlight the need for increased health literacy among farmers in Thailand to ensure correct protective behaviors against chemical exposure and reduce the adverse effects of pesticide exposure on human health.

Reviewing the current state of legacy POP-brominated flame retardants in plastic childcare products and toys: a scoping review protocol

BackgroundDue to their adverse environmental and health impacts, brominated flame retardants (BFRs) are listed in Annex A of the Stockholm Convention for global elimination of production and use. Their health impacts include endocrine disruption, cancer, reproductive effects, and neurobehavioral and developmental disorders in children. Emerging literature suggests that legacy POP-BFRs are increasingly found in consumer products, including those used for and by children. The presence of legacy POP-BFRs in children’s products is a big concern. Children are more vulnerable to chemical exposure risks than adults because their bodies are still developing and fragile. The rising problem is contributed to by the global push towards a circular economy that encourages responsible production and consumption by practising the recycling of waste materials. Waste materials such as electronic and electrical equipment plastics often contain POP-BFRs. POP-BFRs in waste materials are transferred into new products through recycling. The recycled products have become a potential source of exposure to legacy POP-BFRs for vulnerable populations, particularly children. Our scoping review aims to map and summarise the emerging literature. This information is needed to inform evidence-based policies to protect children from toxic exposures.MethodsOur scoping review will follow a methodological framework proposed by Arksey and O’Malley. Peer-reviewed and grey literature on the topic will be retrieved from electronic databases and other relevant sites. Two reviewers will screen titles and abstracts, followed by a full-text review of studies for eligibility based on the established inclusion and exclusion criteria. Data will be extracted, and findings will be mapped in a table according to study settings, types of children’s products tested, and concentration of legacy POP-BFRs in contaminated products. A map chart will be created to display how contaminated products are spread globally.DiscussionBecause of their unique vulnerabilities, children continue to suffer disproportionate exposures to toxic chemicals compared to adults. Information on potential exposures, particularly for children, is crucial to make evidence-based policies. We intend to map and summarise the emerging literature on legacy POP-BFRs in children's products. Findings will be disseminated to relevant stakeholders through publishing in a peer-reviewed scientific journal and policy briefs.Systematic review registrationThe protocol is registered with the Open Science Framework (https://doi.org/10.17605/OSF.IO/7KDE5).

Alat Pelindung Diri Sebagai Upaya Mencegah Risiko Pada Pekerja Sablon Plastik Di Desa Bolon Kecamatan Colomadu Kabupaten Karanganyar Jawa Tengah

The partner in this service is a plastic screen printing business. The number of participants in the activity was 10 screen printing workers. Lectures, discussions, and simulations carry out the method of activity. Data collection techniques through pre and post-test questionnaires conducted before and after socialization activities and simulated use of personal protective equipment. This advocacy activity is carried out on screen printing business owners, aiming to get support from screen printing business owners to participate in preventing the risk of chemical exposure to screen printing workers and screenprinting business owners welcome enthusiastically and participate in service activities. Socialization activities to measure success by conducting pretest and posttest with pretest and posttest results increased the average value according to the target, which was 51%. Workers are also given a simulation of the use of personal protective equipment in the form of a respirator so that they can apply the use of a respirator correctly. The results of assistance after the activity was carried out, all workers had used personal protective equipment in the form of respirators while working to prevent the risk of exposure to chemicals used as screen printing materials. Workers' knowledge of hazards and their control increased by 51% and workers have used personal protective equipment properly to prevent the risk of hazards that arise when working with plastic screen printing worker

Embedded System – Based Pesticides Spraying Robot

The agriculture sector is undergoing a transformation with the integration of robotics and automation. One notable development is the emergence of autonomous pesticide spraying robots, designed to enhance precision, efficiency, and sustainability in crop protection practices. This abstract explores the technological advancements, operational mechanisms, and potential implications of these innovative robots. Autonomous pesticide spraying robots leverage cutting-edge technologies such as artificial intelligence, machine learning, and advanced sensors to navigate fields, identify crop areas, and precisely apply pesticides. Equipped with GPS, LiDAR, and cameras, these robots can map fields, detect obstacles, and optimize spraying patterns in real-time, reducing pesticide usage while ensuring effective pest control. Furthermore, the integration of data analytics enables continuous improvement in spraying strategies, tailored to specific crop types, environmental conditions, and pest pressures. The deployment of autonomous spraying robots offers several benefits to farmers, including increased operational efficiency, reduced labor costs, and minimized environmental impact. By eliminating the need for human operators and optimizing pesticide application, these robots contribute to safer working conditions and reduced chemical exposure risks. Moreover, their ability to operate autonomously for extended periods enhances productivity and scalability in large-scale agricultural operations. Additionally, there is a need for comprehensive training and education to enable farmers to effectively integrate these technologies into their existing practices while maximizing their benefits. modern agriculture, offering precision, efficiency, and sustainability in crop protection. As technology continues to evolve and adoption grows, collaboration among stakeholders is essential to address challenges and unlock the full potential of these innovative solutions for the benefit of farmers, consumers, and the environment.

Chemical and Thermal Exposure Risks in a Multi Compartment Training Structure

Providing NFPA 1403 compliant live-fire training can present thermal and chemical exposure risk to instructors and students. To reduce risk, training academies, fire departments, instructors, and standards setting technical committees need more information on how different training fuels used in common training structures can impact the environment in which firefighter training occurs. This study utilized a traditional concrete training structure with multiple compartments to characterize training environments with three different fuel package materials [i.e., low density wood fiberboard, oriented strand board (OSB), and wood pallets]. Exposure risks for a fire instructor located on either the first or second floor were characterized using measurements of heat flux, air temperature and airborne concentrations of several contaminants including known, probable, or possible carcinogens. It was hypothesized that utilizing a training fuel package with solid wood pallets would result in lower concentrations of these airborne contaminants [aldehydes, polycyclic aromatic hydrocarbons (PAHs) and volatile organic compounds (VOCs)] than wood-based sheet goods containing additional resins and/or waxes. Additionally, it was hypothesized that these concentrations would be lower than in the single compartment Fire Behavior Lab presented in a companion manuscript. For all measured compounds other than hydrochloric acid, airborne concentrations were 10 to 100 times lower than in the Fire Behavior Lab. OSB-fueled fires produced the highest median concentrations of total PAHs and VOCs such as benzene, while the pallet fuel package produced the lowest median concentrations of these compounds. These trends generally followed the qualitative visual obscuration created by each fuel. Additional tests were conducted on the OSB-fueled fires with increased ventilation and an alternate means of reducing visibility through smoldering smoke barrels. This OSB experiment with increased ventilation resulted in the highest temperatures in the fire room but the lowest impact on visibility throughout the structure, as well as the lowest overall concentrations of contaminants in this study. In contrast, the smoldering straw-filled smoke barrel created a highly obscured environment (with minimal impact on thermal environment) and some of the highest concentrations of the targeted contaminants of any test. These data may be useful in balancing obscuration for training with potential exposure to thermal stressors and contaminants.

Evaluation of inhalation risk during quarantine work with quaternary ammonium compounds-based disinfectant

Quarantine work is widely recognized as an indispensable endeavor in curbing the propagation of the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). Furthermore, the heavy workload places workers at a heightened risk of chemical exposure and respiratory damage. Consequently, it is paramount to systematically perform health risk assessments and meticulously oversee the work by wearing personal protective equipment to minimize these risks. To assess the inhalation exposure, this study examined data on disinfectant exposure from quarantine professional users who utilized disinfectants containing quaternary ammonium compounds. Through a survey of 6,199 cases conducted by 300 quarantine professional users who actively engaged in quarantine work, we assembled a database of exposure factors derived from their utilization of spray-type disinfectants for quarantine purposes. Based on these data, we formulated an inhalation exposure algorithm, which considers the time-weighted average (TWA) air concentrations. The test results demonstrated that the industrial-grade respirator mask could prevent a minimum of 68.3 % of particles, reducing respiratory exposure. Consequently, the hazard quotient (HQ) due to disinfectant exposure also decreased. This research is essential in safeguarding the safety and health of professional users engaged in quarantine-related tasks. By implementing strict measures like health risk assessments and personal protective equipment, individuals with quarantine experience can safely carry out their quarantine work. The results of this study are expected to serve as a framework for improving policies and regulations concerning quarantine work and safeguarding the health of professional users.

Release kinetics and risk assessment of additives in plastic advertising banners

Plastic advertising banners (PABs) have been widely used for advertising and publicizing with large usage amount. The PABs are usually added with plenty of chemical additives for improving material performance, and the additives can be released during the lifetime of the PABs. However, limited knowledge is available on the composition and release of the additives in the PABs. In this study, benzenoids were found as the dominant additive categories in PABs. Release kinetics of benzenoid additives with high detection frequency and high abundance from the PABs under indoor and outdoor environments were investigated. During the 150-day release experiment, average release rates of the additives from the PABs under outdoor and indoor environments were 8.3 × 10−10 kg/m2·s and 6.3 × 10−10 kg/m2·s, respectively. The release rates of the additives were negatively related to the thickness of the PAB samples. Health risk assessment indicated that chemicals associated with PABs have potential carcinogenic risks to salesmen in the shopping malls. The risks of chemical exposure associated with PABs to consumers in the shopping malls were acceptable. This study unveils a considerable source of chemical exposure to humans.

Pollutant bioaccumulation in sentinel fish chronically exposed in Iguaçu river reservoirs (Southern Brazil) and human health risk of fish consumption

Bioaccumulation studies in fish mark the initial phase of assessing the risk of chemical exposure to biota and human populations. The Iguaçu River boasting a diverse endemic ichthyofauna, is grappling with the repercussions of human activities. This study delved into the bioaccumulation of micropollutants, the early-warning effects on Rhamdia quelen and Oreochomis niloticus in the Segredo Reservoir (HRS) and the potential risk of human exposure. Two groups of caged fish in three sites of the reservoir were exposed during the autumn-winter and spring-summer, while a third group (O. niloticus) underwent a twelve-month exposure, and inorganic and organic chemicals analysis in water, sediment, and biota. Additionally, metallothionein expression and genotoxicity were employed as biomarkers. PAHs, PCBs, Al, Cu, Fe, and As in water and DDTs, Cu, Zn, and As in sediment surpassed the thresholds set by Brazilian regulations, where DDT exhibited bioaccumulation in muscle, alongside metals in liver, kidney, gills, and muscle tissues. R. quelen showed metallothionein expression whereas DNA damage and NMA frequencies were elevated in target organs and in brain and erythrocytes of O. niloticus during summer. In this species the DNA damage in liver was remarkable after twelve months. Target Hazard Quotients and Cancer Risk values shedding light on the vulnerability of both children and adults. The reservoir's conditions led to heightened sensitivity to micropollutants for R. quelen species. The data presented herein provides decision-makers with pertinent insights to facilitate effective management and conservation initiatives within the Iguaçu Basin.

Advancing chemical safety assessment through an omics-based characterization of the test system-chemical interaction.

Assessing chemical safety is essential to evaluate the potential risks of chemical exposure to human health and the environment. Traditional methods relying on animal testing are being replaced by 3R (reduction, refinement, and replacement) principle-based alternatives, mainly depending on in vitro test methods and the Adverse Outcome Pathway framework. However, these approaches often focus on the properties of the compound, missing the broader chemical-biological interaction perspective. Currently, the lack of comprehensive molecular characterization of the in vitro test system results in limited real-world representation and contextualization of the toxicological effect under study. Leveraging omics data strengthens the understanding of the responses of different biological systems, emphasizing holistic chemical-biological interactions when developing in vitro methods. Here, we discuss the relevance of meticulous test system characterization on two safety assessment relevant scenarios and how omics-based, data-driven approaches can improve the future generation of alternative methods.

Particle transfer mediates dermal exposure of consumers to plasticizers in eraser and pen accessories

Dermal exposure to chemicals released from daily consumer products is a rising concern, particularly for children who are susceptible to unintentional hand-to-mouth transfer and related chemical exposure risk. However, chemical transfer induced by tiny particles of intact products has yet to be adequately addressed. The objective of the present study was to determine the potentiality of particles release from intact erasers and pen grips upon dermal contact by measuring the migration rates of the embedded plasticizers (phthalates and its alternatives). The results showed that billions of particles were released from erasers (0.6–1.2 × 109) and pen grips (0.2–1.6 × 108) upon dermal contact at ambient temperature, with sizes mainly smaller than 1 μm. The composition of eraser leachates was identical to that of the corresponding bulk eraser, as confirmed by Fourier-transform infrared spectroscopy and pyrolysis. Migrated hydrophobic plasticizers may be used as indicators of particle release from erasers and pen grips. The potentiality of particle release was negatively correlated with the total plasticizer contents (r = −0.51; p < 0.05) for both erasers and pen grips. These findings indicated that particles directly released from school supplies and accessories could be a non-negligible source of human exposure to plasticizers.

Exposome epidemiology for suspect environmental chemical exposures during pregnancy linked to subsequent breast cancer diagnosis

Breast cancer is now the most common cancer globally, accounting for 12% of all new annual cancer cases worldwide. Despite epidemiologic studies having established a number of risk factors, knowledge of chemical exposure risks is limited to a relatively small number of chemicals. In this exposome research study, we used non-targeted, high-resolution mass spectrometry of pregnancy cohort biospecimens in the Child Health and Development Studies to test for associations with breast cancer identified via the California Cancer Registry. Second and third trimester archival samples were analyzed from 182 women who subsequently developed breast cancer and 384 randomly selected women who did not develop breast cancer. Environmental chemicals were annotated with the Toxin and Toxin-Target Database for chemical signals that were higher in breast cancer cases and used with an exposome epidemiology analytic framework to identify suspect chemicals and associated metabolic networks. Network and pathway enrichment analyses showed consistent linkage in both second and third trimesters to inflammation pathways, including linoleate, arachidonic acid and prostaglandins, and identified new suspect environmental chemicals associated with breast cancer, i.e., an N-substituted piperidine insecticide and a common commercial product, 2,4-dinitrophenol, linked to variations in amino acid and nucleotide pathways in second trimester and benzo[a]carbazole and a benzoate derivative linked to glycan and amino sugar metabolism in third trimester. The results identify new suspect environmental chemical risk factors for breast cancer and provide an exposome epidemiology framework for discovery of suspect environmental chemicals and potential mechanistic associations with breast cancer.

Operational Risk Identification and Mitigation of the Chemical Production Process of PT. X Using Failure-Mode and Effect Analysis (FMEA) and Chemical Health Risk Assessment (CHRA) Methods

PT. X is a German-based multinational chemical company that produces surfactant as one of its products. As a chemical processing company, the operational activities of the production process in PT. X poses risks that could happen at any time. This research is conducted to identify, analyze, and propose mitigation plan for the risks in one of the plants operated by PT. X. Interviews are conducted to identify the risks using Fishbone diagram as the framework and the Ishikawa method to categorize the causes. There are 86 risks that are identified consisting of 51 operational risks and 35 risks of chemical exposure. To be more thorough, the identified operational risks are assessed using the Failure-Mode and Effect Analysis (FMEA) and the chemical exposure risks are assessed using the Chemical Health Risk Assessment (CHRA). From the 206 risk causes, 31% are caused by Man, 28% are caused by Machine, 22% are caused by Material, 15% are caused by Method, and 5% are caused by the Environment. The FMEA produces Risk Priority Number (RPN) which led to risk prioritizing using the Pareto diagram and risk mapping, resulting in 24 risks being prioritized that consists of 15 medium-level risks and 9 low-level risks with no high-level risk present. The CHRA produces Risk Rating (RR) and Level of Risk that resulted in 77 low-level and 19 moderate-level risks for risk for inhalation exposure, and 9 moderate-level risks and 86 high-level risks for the exposure through dermal contact. It produces the decision of 17 inadequate control measures for chemical exposures. These assessments are further processed to devise the appropriate contingency plan, mitigation plan, and action plan.

Health risks of pest control and disinfection workers after the COVID-19 outbreak in South Korea

The exposure patterns of pest control and disinfection workers have changed after the coronavirus disease 2019 (COVID-19) outbreak, but the health risks of chemical exposure have not been assessed. We identified these workers' chemical exposure patterns and risks before and after the COVID-19 outbreak. We used data conducted between 2018 (pre-pandemic) and 2021 (post-pandemic) from three-year cross-sectional surveys on pest control and disinfection workers. Inhalation and dermal exposure concentrations were estimated using equations based on a biocidal product risk assessment model from the Korean National Institute of Environmental Research. The non-carcinogenic and carcinogenic risks of chemicals were calculated using the United States Environmental Protection Agency risk assessment model. We found that the annual work frequency (50th percentile) of foggers using disinfectants increased the most among all the work types, from 140 uses/year to 176 uses/year after the COVID-19 outbreak. Moreover, all chemicals' non-carcinogenic and carcinogenic risks increased regardless of exposure routes. In the worst scenario (95th percentile), the margin of exposure for citric acid, benzethonium chloride, benzyl-C12-16-alkyldimethyl chlorides, and sodium chlorite of inhalation exposure, and isopropyl alcohol and benzyl-C12-16-alkyldimethyl chlorides of dermal exposure were acceptable (>100) before the COVID-19 outbreak but became unacceptable (<100) after the COVID-19 outbreak. Carcinogenic risks of dichlorvos from inhalation and dermal exposure were above acceptable levels (>10−6) before and after the COVID-19 outbreak but comparatively high after the COVID-19 outbreak. Additionally, significantly more workers experienced health symptoms after the COVID-19 outbreak (p<0.05), with the most common being muscle lethargy (31%), skin/face stinging (28.7%), and breath shortness/neck pain (24.1%).

Volatile organic compounds and metals/metalloids exposure in children after e-waste control: Implications for priority control pollutants and exposure mitigation measures

The decade-long effort to control e-waste in China has made significant progress from haphazard disposal to organized recycling, but environmental research suggests that exposure to volatile organic compounds (VOCs) and metals/metalloids (MeTs) still poses plausible health risks. To investigate the exposure risk faced by children and identify corresponding priority control chemicals, we evaluated the carcinogenic risk (CR), non-CR, and oxidative DNA damage risks of VOCs and MeTs exposure in 673 children from an e-waste recycling area (ER) by measuring urinary exposure biomarker levels. The ER children were generally exposed to high levels of VOCs and MeTs. We observed distinctive VOCs exposure profiles in ER children. In particular, the 1,2-dichloroethane/ethylbenzene ratio and 1,2-dichloroethane were promising diagnostic indexes for identifying e-waste pollution due to their high accuracy (91.4%) in predicting e-waste exposure. Exposure to acrolein, benzene, 1,3-butadiene, 1,2-dichloroethane, acrylamide, acrylonitrile, arsenic, vanadium, copper, and lead posed considerable CR or/and non-CR and oxidative DNA damage risks to children, while changing personal lifestyles, especially enhancing daily physical exercise, may facilitate mitigating these chemical exposure risks. These findings highlight that the exposure risk of some VOCs and MeTs is still non-negligible in regulated ER, and these hazardous chemicals should be controlled as priorities.

Comparison of the chemical health risk assessment of exposure to metal fumes for the furnace operator of a foundry industry using quantitative and semi-quantitative methods

Heavy metals have several adverse effects on the workers' bodies due to their accumulation in the vital organs. Besides that, the current study aimed to assess the health risk of exposure to metal fumes for furnace operators working in a foundry industry based on the three different methods. The current sectional descriptive-analytical research conducted on a foundry industry in Isfahan (Iran) in 2022. Three common methods currently available, including the Semi-Quantitative Risk Assessment Method (SQRCA) and two methods provided based on the US-EPA provided technique, were used in this study. At first, the extent of people's exposure to metal fumes of Fe, Ni, Cr, and Mn was measured. Then, the chemical risk assessment of exposure to these metals' fumes was done using the three methods, and their results were compared. The SPSS Ver.25 has been used for data analysis and comparison in the current study. Results indicated that the furnace operator's exposure to all four metals was above the allowed limit of occupational exposure. The chemical risk assessment results also showed that in the first method (US-EPA-based), the risk of exposure for all workers was acceptable, while in the second method (SQCRA), the risk level of a majority of workers was medium, and in the third method (US-EPA-based), the risk level of a majority of workers was not acceptable. Comparing the methods showed that average risk scores in the first and second methods were significant compared to the exposure to fumes with equivalent concentration (Pvalue<0.05). The average score of carcinogenicity risk in method 3 was significant compared to the concentration of chromium and nickel (P-value < 0.05), but it was not significant for iron and manganese and the non-carcinogenic risk of chromium and nickel. Chemical exposure risk level for the furnace operator was approximately moderate in all three methods. In terms of complexity and information required to implement the method, all three methods were almost the same, with the difference that the results of the first method cannot be generalized to other people who have the same job conditions because individual information such as a person's weight is used to calculate its score.

Analysis of dermal exposure assessment in the US Environmental Protection Agency Toxic Substances Control Act risk evaluations of chemical manufacturing.

The United States Environmental Protection Agency (EPA) regulates chemical manufacture, import, processing, distribution, use, and disposal under the 2016 amended Toxic Substances Control Act (TSCA) for the purposes of protecting the public and sensitive populations-including workers-from chemical exposure risk. The publication of several TSCA risk evaluations provided a unique opportunity to evaluate the evolving regulatory approach for assessing the dermal exposure pathway in occupational settings. In this analysis, the occupational dermal exposure assessment methods employed in several TSCA risk evaluations were assessed. Specifically, a methodology review was conducted for the occupational dermal scenarios of manufacturing and feedstock use in the risk evaluations of three chlorinated organic chemicals: trichloroethylene, carbon tetrachloride, and perchloroethylene. Additionally, alternative exposure estimates were generated using the exposure model IH SkinPermTM. The review and alternative exposure analyses indicate that the current TSCA modeling approach may generate total dermal absorbed doses for chlorinated chemical manufacturing and feedstock use scenarios that are 2- to 20-fold higher than those generated by IH SkinPerm. Best-practice recommendations developed in the methodology review support a tiered, integrated approach to dermal exposure assessment that emphasizes collecting qualitative data; employing validated, peer-reviewed models that align with current industrial practices; and gathering empirical sampling data where needed. Collaboration among industry, EPA, and other stakeholders to share information and develop a standard approach to exposure assessment under TSCA would improve the methodological rigor of, and increase confidence in, the risk evaluation results.

Pelagic and coastal green turtles (Chelonia mydas) experience differences in chemical exposure and effect.

Green turtles foraging in coastal areas are exposed to land-based chemical pollutants that accumulate in the habitats to which they show high site fidelity. However, prior to coastal recruitment, they may be exposed to a different range of chemical threats. The recent development of species-specific in vitro bioassays for marine turtles allows for an effect-based assessment of toxicological endpoints. Blood was collected from green turtles of two life-stages, 'recent recruits' and 'coastal residents', in Hervey Bay and Moreton Bay. Organic contaminants were extracted from blood using the QuEChERS method, and cytotoxicity of the extracts measured in green turtle skin cells. Although not statistically significant, extracts from 'coastal residents' exhibited greater mean toxicity compared to 'recent recruits', possibly indicative of increased chemical accumulation from coastal habitat exposure. The bioassay results also indicated that turtles foraging in Hervey Bay are at greater risk of chemical exposure than those foraging in Moreton Bay.

Exposure levels of PCDD/Fs and PCBs in human blood and the transplacental transfer characteristics in cord blood of newborns near the industrialized area.

Mono-to octa-chlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and polychlorinated biphenyls (PCBs) in pooled blood from the general population living near a typical industrialized area were investigated. Less chlorinated PCDD/Fs (mean: 2602pgL-1) were 7.5 times those of highly chlorinated ones (mean: 349pgL-1). The average ΣPCBs and Σdl-PCBs concentrations in human (cord) blood were 2741 (117) and 18 (0.31) ng L-1, respectively. Higher concentrations of highly chlorinated PCDD/Fs were found in females than in males across different ages. The mean concentrations (and toxic equivalents (TEQs)) of PCDD/Fs were 282 (27) pg L-1 in males and 312 (32) pg L-1 in females. The concentrations of the PCDD/Fs and PCBs increased with age for both males and females, which might be caused by the long half-lives of these compounds and decreases in metabolic rates with age as the metabolic of nutrients, food, and also PCDD/Fs and PCBs would trend to slow. The TEQ of total PCDD/Fs and PCBs was higher in blood from orthopedics patients (107pgL-1) than other patients. This result may be associated with the bone density and pollutant bioaccumulation. In addition, total concentration of PCDD/Fs and PCBs in blood of women at reproductive age were 6.6 and 37 times the cord blood of newborns, respectively. Positive correlation of PCDD/Fs and PCBs especially for the higher chlorinated compounds between female and cord blood were discovered, which might be caused by the transplacental transfer characteristics and blood barrier for macromolecules and reduce the chemical exposure risks for newborns.

Toxic Substances Control Act (TSCA) Implementation: How the Amended Law Has Failed to Protect Vulnerable Populations from Toxic Chemicals in the United States.

Exposures to industrial chemicals are widespread and can increase the risk of adverse health effects such as cancer, developmental disorders, respiratory effects, diabetes, and reproductive problems. The amended Toxic Substances Control Act (amended TSCA) requires the U.S. Environmental Protection Agency (EPA) to evaluate risks of chemicals in commerce, account for risk to potentially exposed and susceptible populations, and mitigate risks for chemicals determined to pose an unreasonable risk to human health and the environment. This analysis compares EPA’s first 10 chemical risk evaluations under amended TSCA to best scientific practices for conducting risk assessments. We find EPA’s risk evaluations underestimated human health risks of chemical exposures by excluding conditions of use and exposure pathways; not considering aggregate exposure and cumulative risk; not identifying all potentially exposed or susceptible subpopulations, and not quantifying differences in risk for susceptible groups; not addressing data gaps; and using flawed systematic review approaches to identify and evaluate the relevant evidence. We present specific recommendations for improving the implementation of amended TSCA using the best available science to ensure equitable, socially just safeguards to public health. Failing to remedy these shortcomings will result in continued systematic underestimation of risk for all chemicals evaluated under amended TSCA.

Moving beyond Risk Quotients: Advancing Ecological Risk Assessment to Reflect Better, More Robust and Relevant Methods.

Under standard guidance for conducting Ecological Risk Assessments (ERAs), the risks of chemical exposure to diverse organisms are most often based on deterministic point estimates evaluated against safety-factor-based levels of concern (LOCs). While the science and guidance for mechanistic effect models (e.g., demographic, population, and agent-based) have long been demonstrated to provide more ecologically relevant effect endpoints upon which risk can be evaluated, their application in ERAs has been limited, particularly in the US. This special issue highlights the state of the science in effect modeling for ERAs through demonstrated application of the recently published Population modeling Guidance, Use, Interpretation, and Development for ERA (Pop-GUIDE). We introduce this issue with a perspective on why it is critical to move past the current application of deterministic endpoints and LOCs. We demonstrate how the current, widely used approaches contain extensive uncertainty that could be reduced considerably by applying models that account for species life histories and other important endogenous and exogenous factors critical to species sustainability. We emphasize that it is long past time to incorporate better, more robust, and ecologically relevant effect models into ERAs, particularly for chronic risk determination. The papers in this special issue demonstrate how mechanistic models that follow Pop-GUIDE better inform ERAs compared to the current standard practice.