Remediation of endosulfan-contaminated water by hairy roots: removal and phytometabolization assessment.

Although many countries banned the insecticide endosulfan, it is still an environmental pollutant. Plants metabolize the two diastereomers of the formulations known as technical grade endosulfan (TGE) by two phase I pathways: hydrolysis leading to less toxic derivatives and oxidation giving endosulfan sulfate which is as toxic as endosulfan itself. We assessed the removal, bioaccumulation and phase I metabolization of TGE from water matrices using hairy root clones (HRs) of three edible species, Brassica napus, Raphanus sativus and Capsicum annuum. B. napus and C. annuum HRs removed 86% of TGE from the bioreaction media in 2 and 96 h, respectively, whereas R. sativus HRs removed 91% of TGE within 6 h of biotreatment. In the experiments with B. napus, only endosulfan sulfate was detected in both biomass and medium, whereas R. sativus and C. annuum accumulated endosulfan sulfate and endosulfan alcohol. Besides, endosulfan lactone was detected in C. annuum reaction medium. Acute ichthyotoxicity assays toward Poecilia reticulata showed that media contaminated with TGE lethal levels did not produce mortality after the phytotreatments. This research highlights the feasibility of using HRs to evaluate plant enzymatic abilities toward xenobiotics and their potential for the design of ex situ decontamination processes.

Concentrations, distribution, and risk assessment of endosulfan residues in the cotton fields of northern Xinjiang, China.

In the current study, surface soil samples were collected from cotton fields in Shawan and Shihezi areas in northern Xinjiang and tested for endosulfan residues using gas chromatography-mass spectrometry. Results showed endosulfan sulfate was the predominant compound in the surface soil studied, followed by ß-endosulfan and α-endosulfan with detection rates of 86.9%, 55.7%, and 49.2%, respectively, for the 61 soil samples collected. The average concentrations of endosulfan sulfate, α-endosulfan, and ß-endosulfan were 0.743, 0.166, and 0.073 µg/kg, respectively. The ratios of α-/ß-endosulfan were below 2.33 in all samples tested, suggesting no new endosulfan was added to the soil and the presence of endosulfan residues in this region was due to historical application in the past. According to the health risk assessment model recommended by the USA Environmental Protection Agency, the health risk of endosulfan residues in the studied area was low, and the maximum values of noncarcinogenic risks for children and adults were 2.30 × 10-5 and 2.70 × 10-6, respectively. Folsomia candida was the most sensitive organism to total endosulfan residues, with 38% of the total sampling sites classified as high risk. For earthworms, the proportion of high risk site was 13%. Lactuca sativa was the most tolerant organism to ∑ESs, with all sampling sites identified as negligible risk. This study provided current status of endosulfan residues and related risk in cotton fields, which could be used to support decision makers to prepare relevant regulations.

Toxicological assessment of low-dose bisphenol A, lead and endosulfan combination: chronic toxicity study in male rats.

In the present study, toxic effects, both alone and combined, of bisphenol A (BPA), lead (Pb) and endosulfan (ES) in the low doses were investigated in rat liver and kidney functions. In the study, bisphenol A (BPA), lead (Pb) and endosulfan (ES) were chosen because although they are the chemicals people are most frequently exposed to, no combined toxic effect studies were conducted with these chemicals. Sixty-four male Wistar albino rats were used in the study, and they were randomly divided into eight groups (n = 8 per group); control, BPA (5 mg/kg), Pb (100 ppm), ES (0.61 mg/kg), BPA+Pb, BPA+ES, Pb+ES and BPA+P+ES. The rats were sacrificed after 65 days of treatment. Severe histopathological changes in the liver and kidney tissues were observed in the rats exposed to BPA+Pb+ES combination. Elevated malondialdehyde (MDA) in the liver and decreased superoxide dismutase activity (SOD) in the kidney tissue were detected in the BPA+Pb+ES group compared to those of the control group. It was found that serum alanine aminotransferase (ALT) and blood urea nitrogen (BUN) and creatinine (CREA) levels were higher in the BPA+Pb+ES combination group than the control group. Also, combined exposure of BPA, Pb and ES caused apoptotic cell numbers and inducible nitric oxide (iNOS) to increase in the liver and kidney tissues. The results of the present study suggested that the BPA, Pb and ES caused more dramatic changes to both histological architecture and cell apoptosis in the liver and kidney tissues when there was a combined exposure.

Assessment of DNA damage induced by endosulfan in grass carp (Ctenopharyngodon idella Valenciennes, 1844).

Endosulfan is an organochlorine pesticide, which is commonly used throughout the world. It accumulates in the environment and may cause significant damage to the ecosystems, particularly to the aquatic environments. The present study was conducted to evaluate the genotoxic effect of endosulfan on the grass carp (Ctenopharyngodon idella) blood. The fish were exposed to three different concentrations, 0.75 ppb/day, 1.0 ppb/day, and 1.5ppb/day of endosulfan for 7, 14, 21, and 28 days. The study was a randomized control trial and the control group was not exposed to endosulfan. The results showed that after 7 days, the level of DNA damage in all the concentrations was significant (P < 0.05), while after 14, 21, and 28 days' trials, highly significant (P < 0.000) level of DNA damage was observed. Hence, time- and dose-dependent DNA damage was observed in fish DNA by comet assay. It is concluded from our results that with the increase in endosulfan concentration and exposure duration, the level of DNA damage also increased. As the current study showed the severe genotoxic effect of endosulfan in Ctenopharyngodon idella, therefore, the imprudent and indiscriminate use of endosulfan should be controlled and monitored by the concerned government authorities.

Residues of endosulfan in cotton growing area of Vehari, Pakistan: an assessment of knowledge and awareness of pesticide use and health risks.

This study is based on self-reported information collected from selected farmers of Vehari District, Punjab, Pakistan, to determine their technical knowledge and awareness about pesticide use and associated environmental and health risks. Moreover, soil contamination by routinely used persistent organochlorine pesticide, endosulfan, was also evaluated. Survey data revealed very low literacy rate (on an average 9th grade education) and technical knowledge (almost missing) of the farmers in Vehari District. The farmers are unable to fully read and understand the instructions about the use of pesticide marked on the containers. They are not fully aware of pesticide persistence and toxicity (73%), unable to identify cotton pests and diseases (86%), and do not know which crop to grow in cotton adjacent fields (100%). Data also revealed that the farmers (100%) do not follow safety measure during pesticide application and are unaware of pesticide toxicity symptoms in human as well as the basic first-aid practices (89%).Poor literacy rate and lack of technical knowledge of farmers in Vehari regarding pesticide use and handling are posing serious environmental and health risks among the local inhabitants, particularly among farmers. Soil analysis results showed that concentration of α- and ß-endosulfan ranged from 0-14 to 0-14.64 µg/mg, respectively. Principal component analysis showed that soil organic matter is the key soil parameter controlling the occurrence and fate of endosulfan under sandy loam soil conditions of Vehari District. There is a serious need of improving technical and environmental knowledge of farmer about pesticide risks on human health in the studied area, in particular, and the entire country in general. Findings are of great use for policymaking in Pakistan to minimize pesticide risks in Pakistan.

Human iPSC-derived neuronal models for in vitro neurotoxicity assessment.

Neurotoxicity testing still relies on ethically debated, expensive and time consuming in vivo experiments, which are unsuitable for high-throughput toxicity screening. There is thus a clear need for a rapid in vitro screening strategy that is preferably based on human-derived neurons to circumvent interspecies translation. Recent availability of commercially obtainable human induced pluripotent stem cell (hiPSC)-derived neurons and astrocytes holds great promise in assisting the transition from the current standard of rat primary cortical cultures to an animal-free alternative. We therefore composed several hiPSC-derived neuronal models with different ratios of excitatory and inhibitory neurons in the presence or absence of astrocytes. Using immunofluorescent stainings and multi-well micro-electrode array (mwMEA) recordings we demonstrate that these models form functional neuronal networks that become spontaneously active. The differences in development of spontaneous neuronal activity and bursting behavior as well as spiking patterns between our models confirm the importance of the presence of astrocytes. Preliminary neurotoxicity assessment demonstrates that these cultures can be modulated with known seizurogenic compounds, such as picrotoxin (PTX) and endosulfan, and the neurotoxicant methylmercury (MeHg). However, the chemical-induced effects on different parameters for neuronal activity, such as mean spike rate (MSR) and mean burst rate (MBR), may depend on the ratio of inhibitory and excitatory neurons. Our results thus indicate that hiPSC-derived neuronal models must be carefully designed and characterized prior to large-scale use in neurotoxicity screening.

Health risk assessment of organochlorine pesticide exposure through dietary intake of vegetables grown in the periurban sites of Delhi, India.

The study investigated the levels of organochlorine pesticides (OCPs) in different types of vegetables grown in periurban area of National Capital Region (NCR), India. Vegetable sampling was carried out in winter and summer season of 2012. A total of 20 different OCPs were determined using gas chromatography (GC) assembled with electron capture detector (ECD). Obtained results showed that average levels of ∑(20)OCP ranged from 83.8 ± 25.5 ng g(-1) in smooth gourd to 222.4 ± 90.0 ng g(-1) in cauliflower. The mean concentrations of different OCPs were observed in order of ∑HCH > ∑CHLs > drins > ∑endosulfan > ∑DDT in all vegetables except in brinjal and smooth gourd. Most of the OCP residues recorded in vegetable samples exceeded the maximum residue levels (MRLs) set by international and national regulatory agencies. Health risk assessment suggests that daily dietary OCP exposure via vegetable consumption was higher for children (mean value 4.25E-05) than adults (mean value 2.19E-05). The hazard quotient (HQ) and lifetime cancer risk (LCR) estimated from dietary exposure of these vegetables were above the acceptable limit and can be considered as a serious concern for Delhi population.

Assessment of endosulfan induced genotoxicity and mutagenicity manifested by oxidative stress pathways in freshwater cyprinid fish crucian carp (Carassius carassius L.).

Over the past few decades, endosulfan, one of the polychlorinated pesticides still in use, has received considerable attention of a number of international regulations and restriction action plans worldwide. This study aimed to evaluate the cytogenetic effects of endosulfan using robust genotoxicity assays, along with the oxidative stress pathways in order to understand biochemical mechanism, in Carassius carassius L. The LC50-96 h (95% confidence limits) value of endosulfan was 0.070 (0.046-0.093) ppm; and on its basis three test concentrations (sub-lethal I: 0.052, II: 0.035 and III: 0.017 ppm) were selected for 35 d in vivo exposure. The mean concentration of endosulfan in aquaria was always constant, when analyzed by dispersive liquid-liquid micro extraction (DLLME) followed by GC-MS. Autopsy was done on days 1, 2, 3, 4, 7, 14, 21, 28 and 35 of endosulfan exposure; the micronucleus formation (MN), authenticated by scanning electron microscopy, and chromosomal aberrations (CA), were induced significantly (p<0.05) in all the treated groups, including positive control cyclophosphamide (4 ppm), when compared to negative control. Similarly lipid peroxidation (LPO) was induced significantly with the maximal at higher concentration (SL-I) on 4th day (722.45%; p<0.01). Antioxidant biomarkers like glutathione reduced, superoxide dismutase and catalase also fluctuated significantly (p<0.01) in all treatment groups. Collective findings demonstrated that genotoxic effects were invariably accompanied and correlated with increased oxidative stress and disturbance of antioxidant enzymes; and the MN and CA assays are useful tools in determining potential genotoxicity of aquatic xenobiotics and might be appropriate as a part of monitoring program.

Assessment of the toxicity of organochlorine pesticide endosulfan in clams Ruditapes philippinarum.

This study is aimed at evaluating the effects of endosulfan in clams (Ruditapes philippinarum). For this purpose, a study was performed on clams exposed to 0.005, 0.05 and 0.5µg/L endosulfan for 15 days. S ubsequently, the level of ethoxyresorufin-O-deethylase (EROD) activity, glutathione-S-transferase (GST) activity, glutathione (GSH) content, superoxide dismutase (SOD) activity, lipid peroxidation (LPO) and DNA strand break was determined in gills and digestive glands. Among the parameters, endosulfan caused significant changes in induction of EROD activity and oxidative stress in clams R. philippinarum. The exposure to endosulfan increased the concentration of EROD, GST, GSH, MDA and decreased the concentration of SOD. Moreover, according to the correlation analysis results, the EROD activity and GSH content in digestive gland as well as GST activity, LPO and DNA damage in both tissues had excellent correlation with endosulfan concentration. These results provided information on potential biomarkers that could be effectively applied to the biomonitoring of aquatic ecosystem in areas susceptible to persistent organochlorine compounds contamination, and also information on toxic effects.

Cost of reproduction. Changes in metabolism and endosulfan lethality caused by reproductive behavior in Hyalella curvispina (Crustacea: Amphipoda).

Biocides are periodically applied in agricultural activities, reaching aquatic systems and acting upon the biota. Amphipods are widely used in toxicity tests because of their sensitivity to a wide range of pollutants. In this work, we report the differential lethality of a widely used pesticide, endosulfan, on the amphipod Hyalella curvispina at two life stages and in three different adult groups, males and females separated by sex and both sexes grouped together. In addition, oxygen consumption of adult groups was determined as a way to estimate the role of behavioral activities and exposure to endosulfan in metabolism shifts. There were no differences between the LC(50) of juveniles and the adults when they were separated by sex (p>0.05). Nevertheless, the LC(50) of adults without sexual differentiation was significantly lower than the LC(50) of juveniles and adults separated by sex (p<0.05). The oxygen consumption rate was higher when adults were grouped without sexual differentiation in the control group. The exposure to low concentrations of endosulfan causes an increase in oxygen consumption in all the treatments. The sexual behavior increased the metabolism and the sensitivity to endosulfan. In future evaluations, adults grouped without sexual differentiation, which were the most sensitive group, should be included in order to mimic the environmental conditions. Using only juveniles or adults separated by sex in toxicity tests may inaccurately estimate the lethality of biocides, especially in species with constant reproductive activities.

Assessment of the sublethal toxicity of organochlorine pesticide endosulfan in juvenile common carp (Cyprinus carpio).

This study is aimed at evaluating the sublethal effects of endosulfan (EDS) in juvenile common carp (Cyprinus carpio). For this purpose, fish were exposed for 15 days to the technical EDS (95% pure) diluted in dimethyl sulfoxide (DMSO) 0.1% of the total volume in water solution in a semi-static system at sublethal concentration (1 µg/L). Subsequently, the liver somatic index (LSI) and factor condition (K) were determined. The total cytocrome P450 (CYP), CYP1A isoform, and the ethoxyresorufin-O-deethylase (EROD) activity were determined from the hepatic microsomal fraction as well as the activity of the oxidative stress enzyme system such as superoxide dismutase (SOD), catalase (CAT), glutathione-S-transferase (GST), glutathione peroxidase (GP(X)), glutathione reductase (GR), and glucose-6-phosphate dehydrogenase (G6PDH). Among the parameters assessed, EDS at the sublethal concentration in subchronic exposure caused significant changes in liver somatic indices as well as induction of the phase I biotransformation system and oxidative stress in juvenile common carp (Cyprinus carpio). Thus, it is seen that the use of biochemical biomarkers of environmental contamination in this study proved to be an extremely important tool for detecting the adverse effects of xenobiotics in the aquatic environment, even at low concentration.

Phytotoxicity of heptachlor and endosulfan sulfate contaminants in soils to economic crops.

The intensive use of organochlorine in the past decades has resulted in contamination of soil worldwide. The phytotoxicity of two organochlorine pesticide, endosulfan sulfate and heptachlor, on the early growth stage of sweet corn (Zea mays), waxy corn (Zea mays) cowpea (Vigna sinensis), cucumber (Cucumis sativus) and water morning glory (Ipomoea aquatica) were studied. In the range of concentration found in Thai agricultural soil, 0.4-40 mg kg(-1) of each pesticide, did not affect the percentage of seed germination. Heptachlor seemed to affect the shoot and root length of test plants more than endosulfan sulfate. The combined effect of both pesticides to corn seedling growth was tested. There was no significant effect on combined treatment of both pesticides to corn growth. The 0.4-40 mg kg(-1) concentration of endosulfan sulfate and heptachlor did not produced significant effect on early growth of plants.

Assessment of the acute toxicity of the organochlorine pesticide endosulfan in Cichlasoma dimerus (Teleostei, Perciformes).

The organochlorine insecticide endosulfan (ES) is widely used despite its high toxicity to fish (96-h LC(50) median value of 2.6 µg L(-1)). This study aimed to assess the acute toxicity, histological and physiological parameters after exposure to 0; 0.25; 1; 2; 3; 4 and 16 µg L(-1) ES for 96 h under semi-static conditions in a freshwater perciform fish, Cichlasoma dimerus. Prior to death, fish exhibited behavior indicative of neurotoxicity. No difference was found in brain AChE activity. A decrease in erythrocyte mean corpuscular volume, mean corpuscular hemoglobin and mean corpuscular hemoglobin concentration in exposed fish suggests a state of anemia. Histological alterations observed in exposed fish included hyperplasia of the interlamellar epithelium, blood congestion in secondary lamellae, and mucous cells hyperplasia and hypertrophy in gills; pycnotic nuclei and hydropic degeneration in liver; testicular damage. These moderate pathological responses in major organs could become crucial during reproduction and under prolonged exposure periods.

Endosulfan and its metabolite, endosulfan sulfate, in freshwater ecosystems of South Florida: a probabilistic aquatic ecological risk assessment.

Endosulfan is an insecticide-acaricide used in South Florida and is one of the remaining organochlorine insecticides registered under the Federal Insecticide Fungicide and Rodenticide Act by the U.S.EPA. The technical grade material consists of two isomers (alpha-, beta-) and the main environmental metabolite in water, sediment and tissue is endosulfan sulfate through oxidation. A comprehensive probabilistic aquatic ecological risk assessment was conducted to determine the potential risks of existing exposures to endosulfan and endosulfan sulfate in freshwaters of South Florida based on historical data (1992-2007). The assessment included hazard assessment (Tier 1) followed by probabilistic risk assessment (Tier 2). Tier 1 compared actual measured concentrations in surface freshwaters of 47 sites in South Florida from historical data to U.S.EPA numerical water quality criteria. Based on results of Tier 1, Tier 2 focused on the acute and chronic risks of endosulfan at nine sites by comparing distributions of surface water exposure concentrations of endosulfan [i.e., for total endosulfan (summation of concentrations of alpha- and beta-isomers plus the sulfate), alpha- plus beta-endosulfan, and endosulfan sulfate (alone)] with distributions of species effects from laboratory toxicity data. In Tier 2 the distribution of total endosulfan in fish tissue (whole body) from South Florida freshwaters was also used to determine the probability of exceeding a distribution of whole body residues of endosulfan producing mortality (critical lethal residues). Tier 1 showed the majority of endosulfan water quality violations in South Florida were at locations S-178 followed by S-177 in the C-111 system (southeastern boundary of Everglades National Park (ENP)). Nine surface water sampling sites were chosen for Tier 2. Tier 2 showed the highest potentially affected fraction of toxicity values (>10%) by the estimated 90th centile exposure concentration (total endosulfan) was at S-178. At all other freshwater sites there were <5% of the toxicity values exceeded. Potential chronic risk (9.2% for total endosulfan) was only found at S-178 and all other sites were <5%. Joint probability curves showed the higher probability of risk at S-178 than at S-177. The freshwater fish species which contain tissue concentrations of endosulfan (total) with the highest potential risk for lethal whole body tissue residues were marsh killifish, flagfish and mosquitofish. Based on existing surface water exposures and available aquatic toxicity data, there are potential risks of total endosulfan to freshwater organisms in South Florida. Although there are uncertainties, the presence of tissue concentrations of endosulfan in small demersal fish, is of ecological significance since these fish support higher trophic level species, such as wading birds.

Human health risk assessment of endosulfan. Part IV: Occupational reentry and public non-dietary exposure and risk.

The California Department of Pesticide Regulation (CDPR) and the United States Environmental Protection Agency (USEPA) released revised draft risk assessments for the pesticidal active ingredient, endosulfan, just 2months apart, in November 2007 and January 2008. The exposure estimates, critical to risk assessment, were calculated by each agency using dissimilar approaches in certain aspects. The scenarios for which exposures and risks were estimated also varied somewhat between the two agencies, although there were substantial overlaps that allowed specific comparisons of exposure and risk estimates. Reasons underlying major differences in estimates of exposure for field workers working in treated crops (reentry exposure) are discussed in this paper. Differences in dislodgeable foliar residue levels calculated by CDPR and USEPA, reflecting endosulfan residues encountered by field workers entering treated orchards and fields, contributed the most to discrepancies in reentry exposure estimates between the two agencies. Additionally, because of differences in legal mandates CDPR estimated exposures for members of the public exposed to endosulfan in ambient air and when swimming, whereas USEPA did not. Exposures calculated for bystanders adjacent to a pesticide application suggest a potential health concern, but estimated swimmer exposures did not.

Human health risk assessment of endosulfan: II. Dietary exposure assessment.

The California Department of Pesticide Regulation (CDPR) and the United States Environmental Protection Agency (USEPA) performed dietary exposure assessments for endosulfan in 1998 and 2002, respectively. Results of the USEPA assessment showed an increased risk for the population sub-group "Children 1-6 years" (>100% of the Population Adjusted Dose [PAD]). USEPA then required registrants to satisfy database uncertainties by performing subchronic neurotoxicity and developmental neurotoxicity studies and, based on the results, USEPA decreased the Food Quality Protection Act (FQPA, 1996) Safety Factor from 10x to 1x. Additionally, several tolerances on commodities consumed in quantity by children were cancelled in 2006. CDPR re-evaluated the dietary risk initially performed in 1998 after review of these same studies. Based on a review of the revised USEPA tolerances, decreased usage, decreased consumption, cancellations, and prior health protective margins of exposure (MOEs>100), CDPR determined that it was not necessary to redo the 1998 exposure assessment. In 2007, USEPA conducted a new human health risk assessment for endosulfan combining food+drinking water residues that characterized dietary risk as %PAD=([Exposure/PAD]x100). For all relevant USEPA population sub-groups, the %PADs were<100% (health protective benchmark).

Human health risk assessment of endosulfan. I: Toxicology and hazard identification.

Endosulfan is persistent in the environment and toxic to wildlife. Legal mandates necessitate that a risk assessments be performed for endosulfan by the California Department of Pesticide Regulation (CDPR) and the United States Environmental Protection Agency (USEPA). This hazard identification (hazard ID) compared critical no-observed effect levels (NOEL) for acute, subchronic and chronic exposure intervals between the agencies. NOELs were discussed in light of their application to numerous exposure scenarios (occupational, general population and dietary). Only the acute oral NOELs differed between CDPR (0.7 mg/kg/day) and USEPA (1.5 mg/kg/day). Pregnant rabbits were considered by CDPR to be more responsive to low gavage doses of endosulfan than non-pregnant female or male rats in the acute study selected by USEPA. NOELs for other exposure routes and durations were similar between agencies. CDPR and USEPA concurred that a Food Quality Protection Act (FQPA, 1996) Safety Factor is not needed after evaluating all studies including a Developmental Neurotoxicity study. The SF was reduced to 1x. NOELs generated from this hazard ID will be used to calculate the Margins of Exposure for all scenarios and subsequently the risk characterization for endosulfan.

Human health risk assessment of endosulfan. Part III: Occupational handler exposure and risk.

The United States Environmental Protection Agency (USEPA) and the California Department of Pesticide Regulation (CDPR) have authority to regulate pesticides, respectively, within the United States and within the state of California. Both agencies are obligated to protect human and environmental health within the geographical boundaries where they have authority. Risk assessment of pesticidal active ingredients is conducted by both USEPA and CDPR, yet the agencies have different legal mandates that influence how they conduct assessments. Exposure estimates are key inputs into the risk assessment. Both agencies released draft risk assessments for endosulfan in the same time frame, and while some exposure estimates were similar, many differed considerably. This paper focuses on the differences in exposure estimates for individuals involved in endosulfan applications (handler exposures). Although CDPR and USEPA relied on the same data sets for their exposure estimates for most handler scenarios, CDPR estimates were in some cases more than an order of magnitude higher than estimates from USEPA. Reasons underlying these disparities, and their effects on risk estimates and resulting regulatory decisions, are discussed in this paper. Additionally, because of differences in legal mandates, CDPR estimated exposures for scenarios lacking data, whereas USEPA did not.

Assessment of the genotoxicity of endosulfan in earthworm and white clover plants using the comet assay.

Endosulfan, as one of the most widely used organochlorine pesticides in the world, has increased the public concern about genotoxicity in soil ecosystems. The comet assay has been widely used in the fields of genetic toxicology and environmental biomonitoring. In the present study we conducted comet assay of endosulfan in earthworm (Eisenia foetida) and white clover (Trifolium repens L.), which are sensitive organisms suitable for acting as a bioindicator for agricultural ecosystems. Earthworms were exposed to endosulfan concentrations of 0.1, 1.0, and 10.0 mg/kg in the soil. White clover roots were immersed in hydroponic pots containing nutrient solutions of different endosulfan concentrations: 0.1, 1.0, and 10.0 mg/L. Tissues from each treatment were collected on the 7th, 14th, 21st, and 28th days of treatment process. Significant effects (p < 0.01) of both concentrations and times of exposure were observed. And endosulfan induced DNA damage in earthworm and white clover nuclei. The comet assay can be used as a reliable tool for early detection of endosulfan.

An assessment of the developmental, reproductive, and neurotoxicity of endosulfan.

BACKGROUND: Endosulfan has been used for over 50 years. Although most analogs have been discontinued, endosulfan has less environmental persistence. Nevertheless, pressure groups are lobbying for a worldwide ban. The reasons are: possible rodent male reproductive toxicity, other endocrine effects and cancer; human epidemiology, and exposure studies; residues appearing in remote areas of the world, e.g., the Arctic. METHODS: The endosulfan toxicology database is described and risks of its use assessed. RESULTS: Endosulfan is an antagonist at the GABA(A) receptor Cl(-) ionophore in mammalian CNS. Rat acute toxicity is moderate, LD(50)=48 (M) or 10 mg/kg/d (F), oral gavage; 130 (M), 70 mg/kg/d (F) dermal; LC(50)=34.5 microg/L (M), 12.6 microg/L (F), inhalation. Critical NOELs for risk assessment: acute oral (gavage)=0.7 mg/kg/d (rabbit developmental); Subchronic oral (diet)=1.2 mg/kg/d (rat reproduction); Chronic oral (diet)=0.6 mg/kg/d. There were no acceptable dermal toxicity studies. The critical acute and subchronic inhalation NOELs=0.001 mg/L, chronic inhalation=0.0001 mg/L (estimated). Toxicity to rat sperm occurred at doses causing neurotoxicity. Endocrine effects, resulting from P450 oxygenase(s) induction, were reversible. Increased cancer, genotoxicity, or histopathology in rodents was not observed in any organ. Possible effects on brain biogenic amine levels were probably secondary. CONCLUSIONS: Epidemiology and rodent studies suggesting autism and male reproductive toxicity are open to other interpretations. Developmental/ reproductive toxicity or endocrine disruption occurs only at doses causing neurotoxicity. Toxicity to the fetus or young animals is not more severe than that shown by adults.