Arsenical Pesticides Research Articles

A Mixed Methods Approach to Understanding the Public Health Impact of a School-Based Citizen Science Program to Reduce Arsenic in Private Well Water.

Exposure to arsenic (As) in well water is a well-documented public health issue for Maine and New Hampshire, as well as for other states in the United States and abroad. Arsenic contamination of well water in these locations is primarily attributed to metasedimentary bedrock that leaches As into groundwater. However, As can also enter groundwater reserves from soils contaminated by the historical use of arsenical pesticides. Approximately half of the households in Maine and New Hampshire rely on private wells, many of which have elevated As. Arsenic exposure has been associated with an increased risk of cancer, cardiovascular disease, reduced infection resistance, and lower intelligence quotient in children. Despite these known health impacts, well water testing and treatment are not universal. We have approached the problem of low well water testing rates in Maine and New Hampshire communities by developing the All About Arsenic (AAA) project, which engages secondary school teachers and students as citizen scientists in collecting well water samples for analysis of As and other toxic metals and supports their outreach efforts to their communities. We assessed this project's public health impact by analyzing student data relative to existing well water quality datasets in both states. In addition, we surveyed private well owners who contributed well water samples to the project to determine the actions taken to mitigate As in well water. Students collected 3,070 drinking water samples for metals testing, and 752 exceeded New Hampshire's As standard of . The AAA data has more than doubled the amount of information available to public health agencies about well water quality in multiple municipalities across both states. Students also collected information about well types and treatment systems. Their data reveal that some homeowners did not know what type of wells they had or whether they had filtration systems. Those with filtration systems were often unaware of the type of system, what the system was filtering for, or whether the system was designed to remove As. Through interviews with pilot survey participants, we learned that some had begun mitigating their exposure to As and other toxic metals in response to test results from the AAA project. A school-based approach to collecting and analyzing private well water samples can successfully reach communities with low testing rates for toxic elements, such as As and other metals. Importantly, information generated through the program can impact household decision-making, and students can influence local and state policymaking by sharing information in their communities. https://doi.org/10.1289/EHP13421.

Arsenic in brown rice: do the benefits outweigh the risks?

Brown rice has been advocated for as a healthier alternative to white rice. However, the concentration of arsenic and other pesticide contaminants is greater in brown rice than in white. The potential health risks and benefits of consuming more brown rice than white rice remain unclear; thus, mainstream nutritional messaging should not advocate for brown rice over white rice. This mini-review aims to summarize the most salient concepts related to dietary arsenic exposure with emphasis on more recent findings and provide consumers with evidence of both risks and benefits of consuming more brown rice than white rice. Despite risk-benefit assessments being a challenging new frontier in nutrition, researchers should pursue an assessment to validate findings and solidify evidence. In the interim, consumers should be cognizant that the dose of arsenic exposure determines its toxicity, and brown rice contains a greater concentration of arsenic than white rice.

Physico-Chemical Quality and Physiological Profiles of Microbial Communities in Freshwater Systems of Mega Manila, Philippines

Studying the quality of freshwater systems and drinking water in highly urbanized megalopolises around the world remains a challenge. This article reports data on the quality of select freshwater systems in Mega Manila, Philippines. Water samples collected between 2020 and 2021 were analyzed for physico-chemical parameters and microbial community metabolic fingerprints, i.e., carbon substrate utilization patterns (CSUPs). The detection of arsenic, lead, cadmium, mercury, polyaromatic hydrocarbons (PAHs), and organochlorine pesticides (OCPs) was carried out using standard chromatography- and spectroscopy-based protocols. Physiological profiles were determined using the Biolog EcoPlate™ system. Eight samples were free of heavy metals, and none contained PAHs or OCPs. Fourteen samples had high microbial activity, as indicated by average well color development (AWCD) and community metabolic diversity (CMD) values. Community-level physiological profiling (CLPP) revealed that (1) samples clustered as groups according to shared CSUPs, and (2) microbial communities in non-drinking samples actively utilized all six substrate classes compared to drinking samples. The data reported here can provide a baseline or a comparator for prospective quality assessments of drinking water and freshwater sources in the region. Metabolic fingerprinting using CSUPs is a simple and cheap phenotypic analysis of microbial communities and their physiological activity in aquatic environments.

Assessment of Phyto-Remediation Quotient of Cultivated Waterleaf Talinum Triangulare on Soil Contaminated With Sodium Arsenate Pesticide

The potential of Waterleaf Talinum triangulare to abstract and consequently remediate As from As-pesticide contaminated soil was investigated by pot experiment and the concentration of As in the plant and soil was determined through mass plasma atomic emission spectroscopy (MP-AES). The composite soil in two separate groups of pots was spiked with 50 mg/kg and 70 mg/kg disodium arsenate pesticide and stands of Waterleaf were grown on them over a 9 weeks growth period. The plant parts (leave and root) and soil after harvesting were pretreated, acid digested and subjected to MP-AES analysis. The results depicted that As concentrations in the plant parts differ at all the treatment levels over the graded period of growth for frequency of harvest and time of harvest and exceeded the maximum permissible limit established by FAO/WHO, and makes the plant unfit for human and animal consumption. The experimental results revealed a statistically significant difference (p<0.05) in the bioaccumulation of As over the graded period of growth at all the treatment levels. The Bio-accumulation factor (BAF) and Bio-concentration factor (BCF) were generally greater than unity (BAF > 1 and BCF > 1) in all treatment levels at the time of harvest which indicates that Waterleaf is suitable for phytoextraction and phytostabilization. However, BAF < 1 and BCF < 1 were observed in the 3rd week and 9th week in the frequency of harvest. Furthermore, Translocation factor (TF <1 and TF > 1) were observed for frequency of harvest and time of harvest, implying that the plant can serve as a bad and good accumulator of As in contaminated soil for phytoremediation if the plant is frequently harvested or allowed to fallow. TF > 1 means that the vegetable will be suitable as a good phytoextractor. It can, therefore, be concluded that Waterleaf can be used for commercial and environmental friendly phytoremediation technology (Green technology) to clean up As polluted sites and environmental monitoring.

Bioaccumulation of Arsenic by Cultivated Waterleaf Talinum triangulare from Soil Contaminated with Sodium Arsenate Pesticide and Health Risk Assessment

Through a pot experiment, the as concentration in the Waterleaf T. Triangulare plant grown on As-pesticide contaminated soil was examined at two treatment doses of 50 mg/kg and 70 mg/kg. After being harvested, the plant's leaves and roots as well as the soil around them were pre-treated, acid-digested, and analyzed for as content using mass plasma atomic emission spectroscopy (MP-AES Model 42100). The results from this analysis were used to determine the health risk posed by ingesting the crop. The study revealed that in all treatment levels for frequency of harvest and time of harvest, the concentration of as in the plant grew continuously over the graded period of growth (between 3 and 9 weeks after planting). Additionally, the increase in as content seen in the plant (leaf) exceeded the permissible limit of 0.1 mg/kg or 0.5mg/kg in vegetables as set by FAO/WHO/USEPA and EC/CODEX, from the third week of growth through the ninth week. The results of this investigation have demonstrated that Waterleaf's edible portions can bioaccumulate as to a great extent. Health risks results depicted that the estimated daily intake of as (EDIM) averages were below 1.0mg/kg/day and the FAO/WHO-recommended permissible tolerated daily intake of 0.002 mg/kg/day for inorganic arsenic. Similarly, the target health quotient (THQ) was below unity (THQ < 1), indicating that there is no expectation of a health danger from ingesting the plant. However, HRI or HQ was greater than unity (HRI or HQ > 1) and target cancer risk (TCR) was within the permissible predicted lifetime risk of getting cancer (1×10-6 to 1 ×10-4), thus, suggesting the possibility of cancerous disease. In addition, the ratio of HRI to RFD indicates that consumption carries a very high health risk of cancer. The overall result indicates that a serious health issue for public health concern either now or in the future may arise from the consumption of waterleaf vegetable cultivated with high use of arsenate pesticides, based on the HRI and TCR which indicates the possibility of developing cancer during a lifetime.

EDTA enhances the photodegradation of p-arsanilic acid in the presence of iron at near-neutral pH

The widespread used organic arsenic pesticides and veterinary drugs have drawn attention for decades. Its photochemical transformation in the surface water contributes to its degradation and the formation of products. The effect of co-existent components like anthropogenic reagents (e.g. ethylenediaminetetraacetatic acid, EDTA) on the photochemical transformation has still to be investigated in depth. Fe(III)-EDTA complex is a common and abundant complex in surface water. In this work, UVA light and simulated sunlight have been used as light sources to explore the effect of Fe(III)-EDTA on the photodegradation of p-arsanilic acid (ASA), used as an organic arsenic feed additive. Whereas ASA hardly absorbs UVA light and can only be directly photolyzed by simulated sunlight, the Fe(III)-EDTA complex is photoactive under either light source. At pH 6, the presence of Fe(III)-EDTA complex enhances the photodegradation efficiency of ASA from 0% to ca. 23% after 180 min reaction under UVA light irradiation, and from 30% to ca. 58% after 45 min reaction under simulated sunlight irradiation. Appropriate amount of EDTA enhances the photodegradation efficiency, whereas excessive EDTA suppresses the initial reaction rate. Mechanistic study has revealed contributions from direct photolysis and photochemical reactions of Fe(III)-EDTA and Fe(III)–OH complexes. Generated •OH has been confirmed as the important contribution. Photodegradation products include inorganic arsenic, organic arsenic, and other organic by-products, and the proportions of these products vary in different light-induced systems due to the diverse reaction pathways. The results of this work improve our understanding of the risks of residual ASA in the environment, allow prediction of its migration and transformation, and show how organic arsenic livestock and poultry feed additives might be removed.

From arsenic to DDT: Pesticides, Fascism and the invisibility of toxic risks in the early years of Francoist Spain (1939-1953)

This paper reviews the way in which Spanish agriculture climbed onto the pesticide treadmill. We claim that Fascist policies and expert advice assembled in the early 1940s accelerated the introduction of pesticides into Spanish agriculture and promoted the emergence of the Spanish pesticide industry in the times of autarky. Agricultural engineers were the key protagonists in this process, but other human and non-human actors also played a pivotal role: a new pest (the Colorado beetle), Francoist politicians, farmers, landowners and industry managers. Our focus is on the use of pesticides against the Colorado beetle (the main threat to the potato crop), and the transition from arsenical pesticides to DDT during the 1940s. We discuss how the politics of autarky offered new opportunities for developing agronomic programmes and the chemical industry and led to the creation of the Register of Pesticides in 1942. We also discuss the role of these regulations in concealing the risks of pesticides from farmers and food consumers. Arsenic pesticides became sources of slow poisoning and tools for social control while reinforcing the alliance of agricultural engineers and Fascist politicians in their autarkic and authoritarian projects. When DDT arrived in Spain, the agricultural engineers praised the low toxicity it had demonstrated (compared to lead arsenate) in its first uses in public health and in military campaigns in Italy. Indeed, the data concerning its potential dangers disappeared from view thanks in part to a large multimedia campaign launched to promote the introduction of the new organic pesticides in Spanish agriculture, which is described at the end of the paper.

Heavy metal pollution in surface sediments of Ghareh-Aghaj River, one of the longest perennial rivers in Iran

River heavy metal contamination (HM) is a serious growing concern across the globe. In Iran, particularly, rivers serve as the most important freshwater resource and underlie the majority of water-demanding activities, resulting in highly polluted rivers. In central Iran, the Ghareh-Aghaj River supports many industrial, municipal, and agricultural land-uses along its path to the Persian Gulf. Although there may be reciprocal HM effects, no study has yet provided supporting scientific evidence on the river’s sediment HM content that might affect the sensitive biodiversity of the river and the Persian Gulf. This study measured the concentrations of five HMs at 11 susceptible and accessible locations along the river as follows: Arsenic (41.83 mg/kg) > Nickel (38.08 mg/kg) > Zinc (24.46 mg/kg) > Copper (18.86 mg/kg) > Lead (4.97 mg/kg). The HM distributions were uniform due to insignificant correlations and high coefficient of variations. According to the results, the river was not polluted with Cu, Zn, and Pb, partly with Ni, and highly with As. The concentration of As exceeded natural values in the river midstream zone and the seawardmost station where the river is exposed to intense agriculture and extensive use of arsenical pesticides and herbicides. This study highlighted the Ghareh-Aghaj River as worthy of further HM investigation, particularly As and urged implementation of HM elimination and monitoring measures to ensure their health and well-functioning.

Relationship of Arsenic and Lead in Soil with Fruit and Leaves of Apple Trees at Selected Orchards in Michigan

Historically, lead arsenate pesticides were commonly used in fruit orchards. Residues of metals from this historical use can persist in soil for decades, which can result in potential risk for humans if they consume fruits grown on contaminated soil. This research was conducted to assess lead and arsenic levels in apples, leaves, and orchard soil where the apples were grown to determine the relationship between metal levels in fruits and fruit products with those in orchard soil. Soil and tree tissue samples were collected from several Michigan farms, and metal concentrations were quantified by using microwave extraction and inductively coupled plasma mass spectrometry. Soil samples were collected at depths of 0 to 20 cm and 20 to 40 cm at a distance of 1 m from the tree trunk. Fruit samples also were processed into juice and pomace fractions to assess the partitioning of arsenic and lead during juice processing. The lead concentration was significantly higher in topsoil (9.4 μg/kg) compared with subsoil (6.9 μg/kg), but the arsenic content did not differ between the two soil layers (P > 0.05). Lead concentrations in apple leaves were correlated with lead in topsoil (0 to 20 cm; P = 0.03). Concentrations of total arsenic in all juice samples were less than 1 μg/kg and showed less potential than lead for uptake and translocation to fruits. There was no significant relationship between soil arsenic content and total arsenic concentrations in juice, pomace, and leaf samples (P > 0.05). Results of this research indicate that lead and total arsenic concentrations in apples and apple products from these selected orchards in Michigan are unlikely to be impacted by the contamination of these metals in orchard soil.

Exposure assessment of toxic metals and organochlorine pesticides among employees of a natural history museum

Chemical compounds such as arsenic, mercury and organochlorine pesticides have been extensively used as preventive and curative conservation treatments for cultural and biological collections to protect them from pest and mold infestations. Most of the aforementioned compounds have been classified as carcinogenic, mutagenic and teratogenic and represent a health risk for members of staff exposed to contaminated objects. The present study addresses the internal exposure of 28 museum employees in Museum für Naturkunde Berlin by measuring arsenic species and mercury in urine as well as hexachlorocyclohexane isomers (α-HCH, β-HCH, γ-HCH), hexachlorobenzene (HCB), dichlorodiphenyltrichloroethane (4,4′-DDT) and its main metabolite, dichlorodiphenyldichloroethylene (4,4′-DDE), and pentachlorophenol (PCP) in blood serum. This study was carried out in order to assess the internal exposure of Natural History Museum staff members to toxic metals and organochlorine pesticides.During a working week, two blood samples and five urine samples were taken from each participant, involving 8 women and 20 men. Information about work activity and exposure related factors such as dust development through work, use of personal protective equipment, as well as a nutrition diary were obtained through a questionnaire. Information on fish and seafood intakes as well as amalgam fillings was also available. The results of the study showed that the museum staff members had quantified concentrations of arsenic (median of 6.4 μg/l; maximum of 339 μg/l), mercury (median of 0.20 μg/l; max of 2.6 μg/l), β-HCH (median of 0.12 μg/l; max of 0.39 μg/l) and 4,4′-DDT (median of 0.050 μg/l; max of 0.82 μg/l). Despite that all the concentrations were below the established reference values, multivariate regression models were able to show that museum staff members are currently exposed to the aforementioned compounds while handling museum objects. To validate our findings, further studies are required.

Effects of Chronic Organic Arsenic Exposure on Rats Kidney - Light Microscopy and Electron Microscopy Study

Introduction: Monosodium methylarsonate (MSMA) is an organic arsenical pesticide widely used in agriculture. Humans are exposed to arsenic through drinking water and anthropogenic activities. Exposure to inorganic arsenic has been linked with multiple health problems. However, studies focusing on chronic organic arsenic exposure and its adverse effects on kidney were limited. The purpose of current study was to determine the effects of chronic organic arsenic exposure in rats kidney by light and electron microscopy. Materials and Method: Thirty-six male SpragueDawley rats were divided into six groups (n=6); three control and three treatment group respectively. All the control group was given distilled water via oral gavage. The treatment group was given oral gavage of MSMA at 42.10 mg/kg body weight (BW) which is equivalent 1/30 LD50 of MSMA. The control and treatment groups were sacrificed at two month, four month and six months interval. Both kidneys harvested for light microscopy and electron microscopy study. Results: Showed progressive changes. The changes initially focal and became diffused involving glomerular; such as glomerular hypercellularity, glomerular shrinkage and dilated Bowman's space. Meanwhile, in proximal tubules, showed diminished brush borders, detachment of nucleus and basement membrane thickening. Electron microscopy showed flattened cell bodies of podocytes, effacement and fusion of podocytes foot processes, thickening of glomerular basement membrane, and discontinuity of brush border. The control and two-months treated group appeared to be normal. Conclusion: Chronic organic arsenic (MSMA) exposure induced chronic kidney injury.

Arsenic(V) sorption kinetics in long-term arsenic pesticide contaminated soils

Historic As contamination of soils occurs throughout the world from mining, industrial and agricultural activities. Sorption processes and rate may strongly influence soil As mobility, which further influences As bioavailability and toxicity. We investigated the kinetics of As(V) sorption by adding the arsenic onto both pristine (non-contaminated) and historically contaminated soils from arsenicals in two contrasting soil types (ferralitic and sandy). Results suggest both pseudo-second order (PSO) and Elovich kinetic models produce robust correlations with good data fits to linearized plots (R2 ≈ 0.900–0.999) that describe the arsenic sorption kinetics for both contaminated and pristine soils. The arsenic sorption data are generally best described by the Elovich model with smaller normalized standard deviations (Δq <5%) than PSO model. In addition, the surface binding to exchangeable and specific sorption of fresh arsenic (63–96%) sites has an impact on the overall low rate of As(V) sorption in the aged contaminated soils. Pristine soils “particularly ferralitic soils” show intra-particle diffusion and/or surface precipitation, which can contribute to a greater irreversibility of As(V) binding in soil. In contrast, the As(V) sorption occurred in the pristine sandy soil in a similar fashion to that of the aged contaminated soil, most likely due to both soil groups having limited strong binding sites. The detailed knowledge from this study provides new insights into the reclamation and management of As contaminated sites.

Hazardous Effects of Arsenic Contaminated Water on the Biological Characteristics of Fishes: A Review

The aim of the current review is to deliberate on arsenic chemistry, its existence in aquatic ecosystem and its effects on the biological systems of fishes which are regarded as potential indicators for any change in water quality. Water is a major storehouse of arsenic which is present in the form of arsenate and arsenite. Anthropogenic activities including unlimited application of arsenic pesticides, industrial activities and mining operations have increased the universal incidence of soluble arsenic above tolerable levels of 0.010 mg/L. Variations in fish behaviour, growth rate, haematological and biological parameters and organ systems have been observed in arsenic contaminated water. Data regarding these parameters indicate that the fish shows aggressive behaviour and its weight increases due to a high arsenic uptake. The production rate of biochemical compounds like carbohydrates, proteins and lipids is reduced due to arsenic bonding with their precursors. Among organ systems, skin is a highly affected organ, while muscles are the least affected due to high arsenic concentration. Low concentration of arsenic results in bioaccumulation, conspicuously in liver and kidney, upon incessant exposure to freshwater fish. This bioaccumulation turns into biomagnification and becomes the cause of lethal diseases in human beings, such as hyperglycaemia, diminution of enzymatic activities and immune system abnormalities. Keeping in view all of these above mentioned facts, it is imperative to take action against excessive arsenic usage and to develop its eco-friendly management ways.

Environmental neglect: endocrine disruptors as underappreciated but potentially modifiable diabetes risk factors.

Type 2 diabetes prevalence is increasing dramatically across the globe, imposing a tremendous toll on individuals and healthcare systems. Reversing these trends requires comprehensive approaches to address both classical and emerging diabetes risk factors. Recently, environmental toxicants acting as endocrine-disrupting chemicals (EDCs) have emerged as novel metabolic disease risk factors. EDCs implicated in diabetes pathogenesis include various inorganic and organic molecules of both natural and synthetic origin, including arsenic, bisphenol A, phthalates, polychlorinated biphenyls and organochlorine pesticides. Indeed, evidence implicates EDC exposures across the lifespan in metabolic dysfunction; moreover, specific developmental windows exhibit enhanced sensitivity to EDC-induced metabolic disruption, with potential impacts across generations. Importantly, differential exposures to diabetogenic EDCs likely also contribute to racial/ethnic and economic disparities. Despite these emerging links, clinical practice guidelines fail to address this underappreciated diabetes risk factor. Comprehensive approaches to stem the tide of diabetes must include efforts to address its environmental drivers.

Arsenical Pesticides in Early Francoist Spain: Fascism, Autarky, Agricultural Engineers and the Invisibility of Toxic Risks

Abstract Lead arsenate was introduced on a massive scale in agriculture in Spain in the early 1940s. With the support of a network of agricultural engineers, the new Francoist state encouraged the production and use of lead arsenate as the main weapon against a newly arrived pest, the Colorado potato beetle. In this paper I discuss arsenical pesticides as sociotechnological products which played a pivotal role in the joint production of both chemical-based agriculture and the emerging Francoist regime in Spain during the 1940s. I review the campaigns organized by agriculture engineers and the making of the new National Register for Phytosanitary Products in 1942. The new regulations promoted research in pesticide quality control but also contributed to concealing the health hazards. This invisibilization of the risks took shape in the confluence of interests of the emerging Francoist state, the new pesticide industry, and the large network of agricultural engineers.

Monitoring of arsenic, mercury and organic pesticides in particulate matter, ambient air and settled dust in natural history collections taking the example of the Museum für Naturkunde, Berlin.

Chemical compounds such as arsenic, mercury and organochlorine pesticides have been extensively used as preventive and curative conservation treatments for cultural and biological collections to protect them from pest and mould infestations. Most of the aforementioned compounds have been classified as carcinogenic, mutagenic and teratogenic and represent a health risk for staff exposed to contaminated objects. A total of 30 compounds were analysed in settled dust, particulate matter and surrounding air collected at several locations in the natural history collections and adjacent rooms of the Museum für Naturkunde, Berlin (MfN, Natural History Museum, Berlin, Germany). Gas chromatography and mass spectrometry techniques were used to quantify dichlorodiphenyltrichloroethane (2,4'-DDT; 4,4'-DDT) and their metabolites (2,4'-DDE; 4,4'-DDE; 2,4'-DDD; 4,4'-DDD), hexachlorobenzene (HCB), 3 isomers of hexachlorocyclohexanes (α-HCH, β-HCH, γ-HCH), the degradation product of γ-HCH with similar toxicological profile, gamma-pentachlorocyclohexene (γ-PCH) and pentachlorophenol (PCP). Atomic absorption spectrometry was used to analyse arsenic and mercury. In order to assess the pathways of contamination with biocides in dust, formations of particulate matter during individual daily work activities, particle number concentrations (PNCs) were measured. Heavy element concentrations found at the MfN were higher than the organochlorine compounds. The maximum concentration of arsenic and mercury in dust was 3507mg/kg and 32mg/kg, respectively, and in air, 48ng/m3 and 1.6ng/m3, respectively. The maximum concentration of the sum of DDTs in dust was 2mg/kg (not detected in air); for PCP, the maximum levels in dust and air were 0.65mg/kg and 10ng/m3, respectively; for γ-HCH, 130mg/kg and 320ng/m3, respectively; and finally, for γ-PCH, 2.1mg/kg and 230ng/m3, respectively. Twelve PNC measurements were obtained from seven different collection rooms and the diaries of the participants' activities. PNCs were highly variable between work activities. Higher personal PNCs were associated with activities like opening storage boxes with prepared animals, reading old books or handling objects. This study has shown that taxidermic objects in museum collection may be a cause for arsenic exposure during handling of objects.

Socioeconomic position and exposure to multiple environmental chemical contaminants in six European mother-child cohorts.

Human exposure to environmental chemical contaminants at critical periods of development can lead to lifelong health consequences. Traditionally, socioeconomically disadvantaged groups are thought to experience higher contaminant exposures; however, this relationship may not hold for all contaminants. Using data from six European birth cohorts (1301 mother-child pairs), we determined biomarkers of exposure to 41 contaminants in biological samples from children (6-12 years) and their mothers during pregnancy, including organochlorine compounds (OCs), polybrominated diphenyl ethers (PBDEs), per- and polyfluoroalkyl substances (PFASs), metals, phthalate metabolites, phenols, and organophosphate (OP) pesticide metabolites. We analyzed these biomarkers with several socioeconomic position (SEP) indicators (maternal education, employment status and family affluence scale). Higher SEP was associated with higher concentrations of several chemicals during pregnancy, including certain PFASs, mercury, arsenic, several phenols, and OP pesticides. Similarly, childhood concentrations of OCs, PFASs, mercury, arsenic, and bisphenol A were higher in higher SEP groups. Conversely, cadmium exposure during pregnancy and exposure to lead and phthalate metabolites in childhood were higher in lower SEP. Principal components representing multiple pollutant exposures showed similar association with SEP. This study demonstrates that environmental chemical contaminant exposure during fetal and childhood life is not exclusively associated to lower SEP and that for several contaminants higher SEP groups incur higher exposure levels.

Health Risk Assessment of Inorganic Arsenic Through Groundwater Drinking Pathway in some Agricultural Districts of Hamedan, West of Iran

Groundwater resources are an important portion of potable water in Hamedan Province, Iran. Therefore, monitoring the pollutants especially heavy metals in these resources are vital to protect the residents’ health. This study aimed to assess the health risks caused by inorganic arsenic pollution through groundwater drinking pathway in four important agricultural areas of Hamedan Province, Iran. In so doing, a total of 180 groundwater wells were chosen randomly for sampling during the spring and summer seasons in 2015. The samples were filtered (0.45 μm), preserved with HNO3 at a pH level lower than 2, and stored in acid-washed polyethylene bottles at 4°C for further analysis. Finally, arsenic content was determined using inductively coupled plasma- optical emission spectrometry (ICP-OES). The results showed that the mean contents of arsenic (mg/L) in groundwater samples taken during the spring were 0.052 for Asadabad plain, 0.007 for Ghahavand plain, 0.006 for Razan plain, and 0.004 for Toyserkan Plain; whereas, the mean content in groundwater samples taken during the summer from Asadabad, Ghahavand, Razan, and Toyserkan plains were 0.058, 0.009, 0.007, and 0.004, respectively. Moreover, based on the computed values of the noncarcinogenic risk of groundwater samples from Asadabad plain, the hazard quotient (HQ) was greater than 1. Therefore, a non-carcinogenic effect is considered to be possible for the inhabitants of this study area. Accordingly, serious considerations including managing the use of agricultural inputs especially arsenical pesticides or herbicides and treatment of arsenic-contaminated groundwater with some proper methods before water ingestion are recommended.

Groundwater Quality beneath an Asian Megacity on a Delta: Kolkata's (Calcutta's) Disappearing Arsenic and Present Manganese.

Kolkata, the capital city of West Bengal, exploits groundwater for public water-supply. The groundwater has been reported to be widely polluted by arsenic (As). Analysis for As in 280 groundwaters from across Kolkata, failed to detect As concentrations >10 μg/L from natural processes. Arsenic concentrations between 10 and 79 μg/L found in 14 of the 280 groundwaters are remnant from a pollution-plume emanating from a single factory site where Paris Green, an arsenical pesticide, was manufactured between 1965 and 1985. In 45% of groundwaters sampled, concentrations of Mn exceed 0.4 mg/L, a putative health guideline value for drinking water. Sporadic minor hazards are posed by Pb > 10 μg/L introduced into groundwater from well-fittings, from 4% of groundwaters with F concentrations between 0.75 and 1 mg/L, and the 14% of groundwaters containing more than 500 mg/L Na, concentrations that might contribute to excessive daily intake of Na. Compounding hazards from As, F, Mn, Na, and Pb, shows that 64% of public wells and 40% of municipal wells supply groundwater of suspect quality. Groundwaters comply with WHO Guideline Values for drinking water in terms of Cr, Cu, Co, NO2, NO3, Sb, Se, and U. Aesthetic guideline values for Fe, Mn, SO4, and Cl are exceeded for many groundwaters.

C. elegans as a model in developmental neurotoxicology

Due to many advantages Caenorhabditis elegans (C. elegans) has become a preferred model of choice in many fields, including neurodevelopmental toxicity studies. This review discusses the benefits of using C. elegans as an alternative to mammalian systems and gives examples of the uses of the nematode in evaluating the effects of major known neurodevelopmental toxins, including manganese, mercury, lead, fluoride, arsenic and organophosphorus pesticides. Reviewed data indicates numerous similarities with mammals in response to these toxins. Thus, C. elegans studies have the potential to predict possible effects of developmental neurotoxicants in higher animals, and may be used to identify new molecular pathways behind neurodevelopmental disruptions, as well as new toxicants.