Potential Human Health Effects Research Articles

Harmful algal bloom-related 311 calls, Cape Coral, Florida 2018-2019.

Harmful algal blooms (HABs) can adversely impact water quality and threaten human and animal health. People working or living along waterways with prolonged HAB contamination may face elevated toxin exposures and breathing complications. Monitoring HABs and potential adverse human health effects is notoriously difficult due to routes and levels of exposure that vary widely across time and space. This study examines the utility of 311 calls to enhance HAB surveillance and monitoring. The study focuses on Cape Coral, FL, USA, located along the banks of the Caloosahatchee River and Estuary and the Gulf of Mexico. The wider study area experienced a prolonged cyanobacteria bloom in 2018. The present study examines the relationship between weekly water quality characteristics (temperature, dissolved oxygen, pH, microcystin-LR) and municipal requests for information or services (algal 311 calls). Each 1 μg/L increase in waterborne microcystin-LR concentrations corresponded with 9% more algal 311 calls (95% confidence interval: 1.03-1.15, p = 0.002). The results suggest water quality monitoring and the 311 dispatch systems may be further integrated to improve public health surveillance.

Effects of radiofrequency electromagnetic fields (RF EMF) on cancer in laboratory animal studies.

The carcinogenicity of radiofrequency electromagnetic fields (RF EMF) has been evaluated by the International Agency for Research on Cancer (IARC) in 2011. Based on limited evidence of carcinogenicity in humans and in animals, RF EMF were classified as possibly carcinogenic to humans (Group 2B). In 2018, based on a survey amongst RF experts, WHO prioritized six major topics of potential RF EMF related human health effects for systematic reviews. In the current manuscript, we present the protocol for the systematic review of experimental laboratory animal studies (cancer bioassays) on exposure to RF fields on the outcome of cancer in laboratory animals. In the framework of WHO's Radiation Program, the aim of this work is to systematically evaluate effects of RF EMF exposure on cancer in laboratory animals. WHO's Handbook (2014) for guideline development will be followed with appropriate adaptation. The selection of eligible studies will be based on Population, Exposures, Comparators, and Outcomes (PECO) criteria. We will include peer-reviewed articles and publicly available reports from government agencies reporting original data about animal cancer bioassays on exposure to RF EMF. The studies are identified by searching the following databases: MEDLINE (PubMed), Science Citation Index Expanded and Emerging Sources Citation Indes (Web of Science), Scopus, and the EMF Portal. No language or year-of-publication restrictions are applied. The methods and results of eligible studies will be presented in accordance with the PRISMA 2020 guidelines. Study evaluation of individual studies will be assessed using a risk of bias (RoB) tool developed by the Office of Health Assessment and Translation (OHAT) with appropriate considerations including sensitivity for evaluating RF EMF exposure in animal cancer bioassays. The final evaluation on the certainty of the evidence on a carcinogenic risk of RF EMF exposure in experimental animals will be performed using the OHAT Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach with appropriate considerations. The protocol has been registered in an open-source repository (PROSPERO). The study is partly financially supported by the World Health Organization. No additional funding was provided outside author salaries through their places of employment.

Validation of supercritical water oxidation to destroy perfluoroalkyl acids

AbstractSome of the same unique physical and chemical properties that make per‐ and polyfluoroalkyl substances (PFAS) desirable for a wide range of commercial applications render them recalcitrant to many liquid treatment technologies. As developments in PFAS‐related toxicological studies increasingly suggest potential adverse human health effects, our industry has made great progress in the past several years on concentrating PFAS into small volume waste streams via adsorption and separation mechanisms. Coupled with residual PFAS‐containing commercial products that are being phased out, management of these concentrated waste streams presents an urgent need for the development and validation of destructive treatment technologies. Here, we field‐validate supercritical water oxidation to treat a concentrated waste stream of 12 perfluoroalkyl acids (PFAAs) with liquid and gaseous analysis, adhering to the recent Other Test Method 45 for stack emission sampling from the United States Environmental Protection Agency (USEPA) and USEPA Method 537.1, with quality control and quality assurance protocols from the Department of Defense/Department of Energy Quality Systems Manual 5.3. Results generated suggest greater than 99.999% destruction and removal efficiency of these 12 PFAAs after two ∼120‐min continuous flow trials, with an overall defluorination percentage of approximately 62.6%.

Airborne Microplastic Concentrations in Five Megacities of Northern and Southeast China.

Airborne microplastics (MPs) are receiving increasing attention due to their ubiquitous nature and the potential human health consequences resulting from inhalation. The limited data for airborne MP concentrations vary widely among studies (∼4 orders of magnitude), but comparisons are tenuous due to the inconsistent collection and detection/enumeration methodologies among studies. Herein, we used uniform methodologies to obtain comparable airborne MP concentration data to assess MP exposure intensity in five Chinese megacities. Airborne MP concentrations in northern cities (358 ± 132 items/m3) were higher than those in southeast cities (230 ± 94 items/m3) but of a similar order of magnitude, unlike previous studies. The majority (94.7%) of MPs found in air samples were smaller than 100 μm, and the main shape of airborne MPs was fragments (88.2%). Polyethylene, polyester, and polystyrene were the dominant polymers comprising airborne MPs. No consistent relationships were detected between airborne MP concentration and typical socioeconomic indices, and the spatial and diurnal patterns for airborne MPs were different from various components of air quality indices (PM2.5, PM10, etc.). These findings reflect the contrasting source/generation dynamics between airborne MPs and other airborne pollutants. Maximum annual exposure of humans to airborne MPs was estimated in the range of 1-2 million/year in these megacities, highlighting the need for additional research examining the human health risks from the inhalation of airborne MPs.

Human Health Effects of Microplastics in Drinking Water: A Review

Introduction: Polymer products have become inexpensive, convenient and widely used in all spheres of everyday life recently. Microplastics are found in seawater, wastewater, fresh water, foodstuffs, and air. Over the past few years, the presence of microplastics in treated tap and bottled water has been reported, raising questions and concerns about their potential human health effects. Objective: To summarize and systematize the results of studying health effects of exposure to microplastics in potable water. Materials and methods: A literature review was done based on ten topical articles and reviews published in 2014–2021 out of 64 sources found in the PubMed and Scopus international databases and the Russian Science Citation Index (RSCI). Results and conclusions: Generalization and systematization of the published research data demonstrated the lack of strong evidence to draw conclusions about human health effects of microplastics. Information on toxicokinetics and toxicodynamics of ingested microplastic particles is absent just like the studies of the most common shapes and sizes of plastic particles and health risks from exposure to such particles in drinking water.

Probabilistic multi-pathway human health risk assessment due to heavy metal(loid)s in a traditional gold mining area in Ecuador

Mining operations are important causes of environmental pollution in developing countries where mining waste management is not adequate. Consequently, heavy metal(loid)s are easily released into the environment, being a potential risk to human health. This study carries out a Bayesian probabilistic human health risk assessment, related to multi-pathway exposure to heavy metal(loid)s in a gold mining area in Southern Ecuador. Concentrations of As, Cd, Cr, Cu, Ni, Pb, and Zn in tap water, surface water, and soil samples, were analyzed to assess the potential adverse human health effects based on the Hazard Index (HI) and Total cancer risk (TCR). Adults and children residents were surveyed to adjust their exposure parameters to the site-specific conditions. Exposure to heavy metal(loid)s resulted in unacceptable risk levels for human health in the two age groups, both carcinogenic (TCR > 1 × 10−5) and non-carcinogenic (HI > 1) through ingestion of tap water and incidental ingestion of surface water. Sensitivity analysis showed that As concentration in waters and exposure frequency were the main contributors to risk outcome. Exposure to soil via accidental ingestion and dermal contact was below the safety limit, not posing a risk to human health. These findings can provide a baseline for the environmental management of the mining area and indicate the need for further research on As pollution in water and its implications on the health of the inhabitants of mining communities.

Validation of microplastic sample preparation method for freshwater samples

The global presence of microplastics in the environment is well documented nowadays. Studies already showed the potential risks that microplastic particles might cause to the ecosystem, while potential human health effects are currently under investigation. As one of the main inputs of these crucial researches, the concentration of microplastics in the environment should be measured precisely, confidently and monitored regularly to determine exposure levels of these pollutants. Some study highlights, that the results are usually inconsistent and uncertain, due to different sampling and sample preparation methods and the lack of quality assurance and quality control of these processes. The need for a standardized methodology is an emerging issue, as this would provide the right tools to establish a global monitoring system of microplastics.Validated sample preparation methods of water (especially freshwater) samples for microplastic analysis are rarely described. To fulfil the gap, this study aims to create and validate a special toolset and the related standard operating procedure for enhanced sample preparation. A newly developed equipment, the Small Volume Glass Separator was designed to easily isolate microplastics from freshwater samples and concentrate the treated sample in a small volume, thus reducing the brine solution use and the sample transfer steps. These features enable better prevention of contamination and making sample preparation easy, fast and cost-effective. The Small Volume Glass Separator and the related standard operation procedure was validated on model freshwater and wastewater samples with the use of fluorescently tagged microplastics and environmentally relevant microplastics (fragments, fibres). Recoveries were measured with optical microscopy under UV light and with near-infrared spectroscopy/microscopy. Recovery tests with fluorescently tagged microspheres showed that average recovery with the Small Volume Glass Separator is 12-39% higher than that of a widespread sample preparation method. This procedure was also able to recover on average 64%±29% of all the environmentally relevant particles during the validation process. Results show that size and density have a great influence on potential particle loss. Recovery of smaller particles are less with both methods than that of the larger particles, but Small Volume Glass Separator yielded significantly higher recovery for more dense particles. The results of this study help to better understand particle loss during sample preparation and thus contribute to the establishment of standardised microplastic analysis processes.

A conceptual model of hydrogeological function and perchlorate transfer in the unconfined Champagne Chalk aquifer (NE France)

Abstract Groundwater of the unconfined Chalk aquifer in Champagne-Ardenne (NE France) is contaminated by perchlorate ( ClO 4 − ), a persistent water-soluble anion. The Chalk aquifer is a crucial water resource of the region, with complex hydraulic properties. The presence of ClO 4 − is of concern due to its potential adverse human health effects. In France, three sources of ClO 4 − contamination are suspected: industrial, military and agricultural. Both a comprehensive understanding of hydrogeological characteristics of the aquifer, and a sound knowledge of sources and behaviour of ClO 4 − in groundwater are required to allow the sustainable use of this groundwater resource. From data acquired during hydrogeological, geochemical, isotopic ( ClO 4 − ) and groundwater age (CFCs and SF 6 ) studies, and historical investigations in a study area located east of Reims, a conceptual model of Chalk aquifer function and ClO 4 − transfer has been established. High spatio-temporal heterogeneities in the unconfined Chalk aquifer are discussed. Different correlations between ClO 4 − , major ions and groundwater-level fluctuations are shown and interpreted, highlighting main factors governing the Chalk groundwater geochemistry and ClO 4 − transfer mechanisms, including water-level fluctuation, groundwater residence time, thickness of the unsaturated zone, superficial formations, distribution of fissure networks, aquifer–river relationships, origin and location of ClO 4 − in soil and human activity.

To which extent are per-and poly-fluorinated substances associated to metabolic syndrome?

Exposure to per- and polyfluoroalkyl substances (PFAS), ubiquitous persistent environmental contaminants, has led to substantial global concern due to their potential environmental and human health effects. Several epidemiological studies have assessed the possible association between PFAS exposure and risk of metabolic syndrome (MetS), however, the results are ambiguous. The aim of this study was to assess the current human epidemiologic evidence on the association between exposure to PFAS and MetS. We performed a systematic search strategy using three electronic databases (PubMed, Scopus, and Web of Science) for relevant studies concerning the associations of PFAS with MetS and its clinical relevance from inception until January 2021. We undertook meta-analyses where there were five or more studies with exposure and outcomes assessments that were reasonably comparable. The pooled odd ratios (ORs) were calculated using random effects models and heterogeneity among studies was assessed by I2 index and Q test. A total of 12 cross-sectional studies (10 studies on the general population and two studies in the occupational settings) investigated the association between PFAS exposure and MetS. We pooled data from seven studies on the general population for perfluorooctanoic acid (PFOA) and perfluorooctanesulfonate (PFOS) and five studies for perfluorohexanesulfonate (PFHxS) and perfluorononanoic acid (PFNA). Predominately, most studies reported no statistically significant association between concentrations of PFAS and MetS. In the meta-analysis, the overall measure of effect was not statistically significant, showing no evidence of an association between concentrations of PFOA, PFOS, PFNA, and PFHxS and the risk of MetS. Based on the results of the meta-analysis, current small body of evidence does not support association between PFAS and MetS. However, due to limited number of studies and substantial heterogeneity, results should be interpreted with caution. Further scrutinizing cohort studies are needed to evaluate the association between various and less well-known PFAS substances and their mixture with MetS and its components in both adults and children in different settings.

Drug Delivery With Carbon-Based Nanomaterials as Versatile Nanocarriers: Progress and Prospects

With growing interest, a large number of researches have been conducted on carbon-based nanomaterials (CBNs). However, their uses are limited due to comprehensive potential environmental and human health effects. It is often confusing for researchers to make an informed choice regarding the versatile carbon-based nanocarrier system and its potential applications. This review has highlighted emerging applications and cutting-edge progress of CBNs in drug delivery. Some critical factors like enzymatic degradation, surface modification, biological interactions, and bio-corona have been discussed here. These factors will help to fabricate CBNs for effective drug delivery. This review also addresses recent advancements in carbon-based target specific and release controlled drug delivery to improve disease treatment. The scientific community has turned their research efforts into the development of novel production methods of CBNs to make their production more attractive to the industrial sector. Due to the nanosize and diversified physical properties, these CBNs have demonstrated distinct biological interaction. Thus long-term preclinical toxicity study is recommended before finally translating to clinical application.

Study of certain heavy metals with potential human health effects

Heavy metals influence the human body directly or indirectly. Some of these heavy metals including Cu, Co, Mn, and Zn have functional roles that are important for the body’s various physiological and biochemical activities. But, several of these heavy metals, at high-dose, could be dangerous to the body. While, others like Cd, Pb, and Cr in minute amounts have harmful effects in the body that cause acute and chronic toxicity in humans. Unmonitored drainage processes in Iraqi rivers have been identified as this river is considered to be the main source of drinking water in Al-Abasia City; hence, the present study aims to detect levels of some heavy metals in the Al-Abasia River. The current study indicates that the highest concentrations of the heavy metals were recorded during winter, while the lowest values were reported during summer, except Pb, Fe, and Co. All heavy metals exceeded Iraqi freshwater content limits, excluding Cu, and Fe.

Development of an analytical method based on solid-phase extraction and LC-MS/MS for the monitoring of current-use pesticides and their metabolites in human urine

Pyrethroids, organophosphorus pesticides and fipronil have been listed as priority chemicals in human biomonitoring studies because of their wide use and potential health effects in humans. The determination of 13 pesticides, including pyrethroids (deltamethrin, cypermethrin, permethrin, cyfluthrin, bifenthrin), organophosphorus (chlorpyrifos, chlorpyrifos-methyl, and malathion), fipronil, neonicotinoids (imidacloprid, acetamiprid and thiacloprid) and triazole (prothioconazole), together with 13 corresponding metabolites in human urine samples was achieved by solid-phase extraction and analysis by liquid chromatography coupled to tandem mass spectrometry. All targeted compounds, except malathion dicarboxylic acid, were measured with a mean within-accuracy (n = 5) of 71%–114% (RSD: 1%–14%) and between-run (n = 15) accuracy of 80%–118% (RSD: 2%–14%). Limits of quantitation of the targeted analytes ranged from 0.1 to 16 pg/mL. The detection result of urine samples from 25 volunteers indicated that the detection frequencies of 3,5,6-trichloro-2-pyridinol (median: 448 pg/mL), 6-chloropyridine-3-carboxylic acid (median: 193 pg/mL), 2-methyl-3-phenylbenzoic acid (median: 181 pg/mL), 3-phenoxybenzoic acid (median: 99 pg/mL), 2-isopropyl-6-methyl-4-pyrimidinol (median: 77 pg/mL), cyfluthrin (median: 59 pg/mL), cis-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropanecarboxylic acid (cis-DCCA, median: 53 pg/mL), trans-DCCA (median: 25 pg/mL), prothioconazole (median: 21 pg/mL), imidacloprid (median: 7 pg/mL), and prothioconazole-desthio (median: 1 pg/mL) were > 50%. The obtained results show that the validated method is suitable for the human biomonitoring of these current-use pesticides and their metabolites.

Heavy metal concentrations in five fish species from the Gulf of Guinea and their human health implications

A major impact of marine pollution is the contamination of fish, which has become an issue of concern due to the potential adverse human health effects. Therefore, this study assessed heavy metal (Cu, Ni, Fe, Cd, Pb, Zn and Hg) concentrations in different parts of five fish species namely S. aurita, E. encrasicolus, S. colias, B. auritus and P. bellottii from the Gulf of Guinea and their implications for human health. The results showed that Cd and Pb concentrations in all the analysed fish species were below their respective detection limits of 0.01 mg kg−1 dw and 0.05 mg kg−1 dw and thus pose low health risks. On a wet weight basis, the mean metal concentrations in fish muscle ranged from 0.04 to 0.31 mg kg−1 for Cu, 1.23 to 3.87 mg kg−1 for Fe, 0.20 to 0.39 mg kg−1 for Ni, 0.17 to 0.42 for Zn, and 0 to 0.05 mg kg−1 for Hg. Although these measured metal concentrations were within permissible limits for human consumption, the calculated hazard quotients indicated that the concentrations of Hg in S. aurita, S. colias and B. auritus pose significant health risks.

Human Health Risk Assessment for Exposure to Potentially Toxic Elements in Polluted Rivers in the Ecuadorian Amazon

Anthropogenic activities performed in the Ecuadorian Amazon have released potentially toxic elements (PTEs) into the rivers, causing severe environmental pollution and increasing the risk of exposure to the residents of the surrounding areas. This study aims to carry out a human health risk assessment using deterministic and probabilistic methods to estimate the hazard index (HI) and total cancer risk (TCR) related to multi-pathway human exposure to PTEs in polluted rivers. Concentrations of Al, Cd, Cr, Cu, Hg, Ni, Pb, and Zn in surface water and sediment samples from rivers on the Ecuadorian Amazon were considered to assess the potential adverse human health effects. As a result, deterministic and probabilistic estimations of cancer and non-cancer risk through exposure to surface waters and sediments were above the safety limit. A sensitivity analysis identified the concentration of PTEs and the exposure duration (ED) as the two most important variables for probabilistic health risk assessment. The highest risk for receptors was related to exposure to polluted sediments through incidental ingestion and dermal contact routes. According to the deterministic estimation, the human health risk through ingestion of water was above the threshold in specific locations. This study reveals the potential health risk to which the population is exposed. This information can be used as a baseline to develop public strategies to reduce anthropogenic pollution and exposure to PTEs in Ecuadorian Amazon rivers.

Towards guidelines for time-trend reviews examining temporal variability in human biomonitoring data of pollutants

In the last few decades, a plethora of studies have focused on human biomonitoring (HBM) of chemical pollutants. Reviewing the copious HBM data reported in these studies is essential for evaluating the effectiveness of pollution management efforts, for example by evaluating time-trends. Nevertheless, guidance to systematically evaluate time trends in published HBM data has never been developed. In this study, we therefore present a proposal for guidelines to conduct “time-trend reviews” (TTRs) that examine time trends in published large HBM datasets of chemical pollutant concentrations. We also demonstrate the applicability of these guidelines through a case study that assesses time-trends in global and regional HBM data on mercury. The recommended TTR guidelines in this study are divided into seven steps: formulating the objective of the TTR, setting up of eligibility criteria, defining search strategy and screening of literature, screening results of search, extracting data, analysing data, and assessing certainty, including the potential for bias in the evidence base. The TTR guidelines proposed in this study are straightforward and less complex than those for conducting systematic reviews assessing datasets on potential human health effects of exposure to pollutants or medical interventions. These proposed guidelines are intended to enable the credible, transparent, and reproducible conduct of TTRs.

A review of microbes and chemical contaminants in dairy products in sub-Saharan Africa.

Animal milk types in sub-Saharan Africa (SSA) are processed into varieties of products using different traditional methods and are widely consumed by households to support nutritional intake and diet. Dairy products contain several microorganisms, their metabolites, and other chemical compounds, some with health benefits and many others considered as potential health hazards. Consumption of contaminated milk products could have serious health implications for consumers. To access the safety of milk products across SSA, studies in the region investigating the occurrences of pathogens as well as chemical compounds such as heat stable toxins and veterinary drug residues in animal milk and its products were reviewed. This is done with a holistic view in light of the emerging exposome paradigm for improving food safety and consumer health in the region. Herein, we showed that several published studies in SSA applied conventional and/or less sensitive methods in detecting microbial species and chemical contaminants. This has serious implications in food safety because the correct identity of a microbial species and accurate screening for chemical contaminants is crucial for predicting the potential human health effects that undermine the benefits from consumption of these foods. Furthermore, we highlighted gaps in determining the extent of viral and parasitic contamination of milk products across SSA as well as investigating multiple classes of chemical contaminants. Consequently, robust studies should be conducted in this regard. Also, efforts such as development cooperation projects should be initiated by all stakeholders including scientists, regulatory agencies, and policy makers to improve the dairy product chain in SSA in view of safeguarding consumer health.

Bioaccumulation and Human Risk Assessment of Heavy Metals in Oreochromis niloticus and Clarias gariepinus Fish Species from the Golinga Reservoir, Ghana

ABSTRACT The Nile tilapia (Oreochromis niloticus) and African catfish (Clarias gariepinus) from the Golinga reservoir in Northern Ghana are consumed as an alternative source of protein. In the current study, levels of selected metals (As, Cd, Fe, Co, Cr, Cu, Mn, Mo, Ni and Pb) in the two fish species and the fish condition were determined, and potential human health effects assessed. The metal concentrations in the edible fish muscles ranged from 0.16 mg kg-1 (Mn) to 101 mg kg-1 (Pb). The weight-length relationships showed that both fish were growing isometrically, and bioaccumulation of metals from the reservoir was considered insignificant with bioconcentration factors below 100 except for Mn, whose value was 161 in the gills of Oreochromis niloticus. The health risk assessment showed that Pb, Cd and As had Target Hazard Quotient values above 1 for both fish species, with that of As being as high as 19.6 for Oreochromis niloticus. The target cancer risk values for As, Cd, Cr and Pb were above the non-risk threshold of <10-6, indicating the risk of cancer developing over the years due to fish consumption. The metal concentration in the fish in the reservoir should therefore be constantly monitored and potential health risks associated with frequent consumption of the fish assessed. Keywords: fish; health risk assessment; Nile tilapia; Target Hazard Quotient; trace metals

Evaluating imidacloprid exposure among grape field male workers using biological and environmental assessment tools: An exploratory study.

Imidacloprid is a neonicotinoid insecticide commonly injected through agricultural drip irrigation systems to reduce the population of vine mealybugs (P. ficus) in grape farms. There is a growing concern of potential human health effects of imidacloprid, however, there is limited information on the exposure to imidacloprid in farm workers. Imidacloprid exposure was evaluated in this exploratory study of 20 male migrant grape workers sampled five days after imidacloprid was injected in the irrigation system during winter and summer seasons. We administered a questionnaire on work activities, exposure characteristics, and socio-demographics and collected personal air, hand wipe, and spot urine samples. Heat exposure was also assessed. Spearman's correlation coefficients and Wilcoxon rank-sum tests were utilized to evaluate associations and differences in imidacloprid exposures with socio-demographic, occupational, and environmental characteristics. All participants had less than a high school education and about half identified an Indigenous language as their primary language. Although not detected in air samples, imidacloprid was detected in 85% of the hand wipes (median: 0.26: 0.41 μg/wipe, range: 0.05-7.10 μg/wipe). The majority of participants (75%) had detectable urinary concentrations of imidacloprid (median: 0.11μg/g creatinine, range: 0.05-3.90μg/g of creatinine), and nearly all (95%) had detectable urinary concentrations of 5-hydroxy-Imidacloprid (5-OH-IMI), a metabolite of imidacloprid (median: 1.28μg/g creatinine, range: 0.20-27.89μg/g creatinine). There was a significant correlation (p<0.001) between imidacloprid in hand wipes and urinary imidacloprid and 5-OH-IMI (rs: 0.67 for imidacloprid and 0.80 for 5-OH-IMI). Hand temperature was significantly and positively correlated (p<0.05) with imidacloprid concentration on hand wipes (rs: 0.70), and urinary biomarkers (rs: 0.68 for imidacloprid, and 0.60 for 5-OH-IMI) suggesting that working in high temperatures may influence the exposure and absorption of imidacloprid. Thus, research on farm workers would benefit in the future by evaluating imidacloprid exposure in relation to heat stress and other occupational factors.

Selection of an Optimal Abrasion Wheel Type for Nano-Coating Wear Studies under Wet or Dry Abrasion Conditions.

Nanocoatings have numerous potential applications in the indoor environment, such as flooring finishes with increased scratch- and wear-resistance. However, given concerns about the potential environmental and human health effects of nanomaterials, it is necessary to develop standardized methods to quantify nanomaterial release during use of these products. One key choice for mechanical wear studies is the abrasion wheel. Potential limitations of different wheels include the release of fragments from the wheel during abrasion, wearing of the wheel from the abrasion process, or not releasing a sufficient number of particles for accurate quantitative analysis. In this study, we evaluated five different wheels, including a typically used silicon oxide-based commercial wheel and four wheels fabricated at the National Institute of Standards and Technology (NIST), for their application in nanocoating abrasion studies. A rapid, nondestructive laser scanning confocal microscopy method was developed and used to identify released particles on the abraded surfaces. NIST fabricated a high performing wheel: a noncorrosive, stainless-steel abrasion wheel containing a deep cross-patch. This wheel worked well under both wet and dry conditions, did not corrode in aqueous media, did not release particles from itself, and yielded higher numbers of released particles. These results can be used to help develop a standardized protocol for surface release of particles from nanoenabled products using a commercial rotary Taber abraser.

Phthalate Exposure and Long-Term Epigenomic Consequences: A Review.

Phthalates are esters of phthalic acid which are used in cosmetics and other daily personal care products. They are also used in polyvinyl chloride (PVC) plastics to increase durability and plasticity. Phthalates are not present in plastics by covalent bonds and thus can easily leach into the environment and enter the human body by dermal absorption, ingestion, or inhalation. Several in vitro and in vivo studies suggest that phthalates can act as endocrine disruptors and cause moderate reproductive and developmental toxicities. Furthermore, phthalates can pass through the placental barrier and affect the developing fetus. Thus, phthalates have ubiquitous presence in food and environment with potential adverse health effects in humans. This review focusses on studies conducted in the field of toxicogenomics of phthalates and discusses possible transgenerational and multigenerational effects caused by phthalate exposure during any point of the life-cycle.