Pesticides contamination in the Thamirabarani, a perennial river in peninsular India: The first report on ecotoxicological and human health risk assessment

Large scale screening and quantification of micropollutants in fish from the coastal waters of Cochin, India: Analytical method development and health risk assessment

Urban estuarine and coastal water receive several micropollutants through industrial and agricultural influxes. The bioaccumulation of these micropollutants in fish and their entry into the coastal population's food chain raises significant food safety concerns. Hence, a comprehensive analytical method was developed for ultra-trace level quantification of 345 micropollutants in fish. The optimized sample preparation method could extract compounds suitable for both GC-MS/MS and LC-MS/MS analysis simultaneously. The target list of contaminants included 278 agricultural pesticides and also 102 endocrine disruptors covering polyaromatic hydrocarbons, polychlorinated biphenyls, organochlorines, and endocrine-disrupting pesticides. The GC-MS/MS with large volume injection (LVI) technique, and LC-MS/MS operating in MRM mode, achieved an LOQ of <2.00 ng/g for most of the analytes. The extraction strategy involved tri-phase partitioning between water, acidified acetonitrile, and hexane, followed by salting out. Dispersive solid phase cleanup (dSPE) with C18, Z-Sep+, CaCl2, and MgSO4 was able to reduce the matrix influence, and the method achieved satisfactory recovery in the range of 70.0-120.0 % for all the target analytes. The repeatability and reproducibility relative standard deviation values of the measured analytes were <20.0 %, and the Horwitz ratio values were well below 2. The method was used to accurately measure the target micropollutants in fish from the Cochin estuary, the highly urbanized portion of the Vembanad Lake, and an important Ramsar site. At least one or more of the 41 different micropollutants were identified and quantified in about 90.7 % of the 108 samples analyzed. The importance of large-scale screening and trace-level quantification methods in environmental monitoring and risk assessment is underscored by the results. The risk assessment showed a moderate risk of exposure to the nearby coastal population through the food chain.

Uncovering global risk to human and ecosystem health from pesticides in agricultural surface water using a machine learning approach

Pesticides typically co-occur in agricultural surface waters and pose a potential threat to human and ecosystem health. As pesticide screening in global agricultural surface waters is an immense analytical challenge, a detailed risk picture of pesticides in global agricultural surface waters is largely missing. Here, we create the first global maps of human health and ecological risk from pesticides in agricultural surface waters using random forest models based on 27,411 measurements of 309 pesticides and 30 geospatial parameters. Our global risk maps identify the hotspots, mainly in Southern Asia and Africa, with extensive pesticide use and poor wastewater management infrastructure. We identify 4 and 5 priority pesticides for protecting the human and ecosystem health, respectively. Importantly, we estimate that 305 million people worldwide are at potential health risk associated with the surface-water pesticide mixture exposure, with the vast majority (86%) being in Asia. We further identify the hotspots in the Ganges River basin in India, where more than 170 million people are at potential health risk. As pesticides are increasingly used to ensure the food production due to future population growth and climate change, our findings have implications for raising awareness of pesticide pollution, identifying the hotspots and helping to prioritize testing.

Occurrence of pesticide residues and associated ecological risks assessment in water and sediment from selected dams in northern Ghana

Pesticides are chemicals used to enhance crop production. However, their residues can persist and accumulate in various environmental settings. This study assessed the occurrence of pesticide residues and ecological risks in surface water and sediment from the Libga and Builpela dams in northern Ghana. A total of 42 pesticides were analysed. Toxic units were used to assess the acute risk to sediment-dwelling organisms and aquatic biota. Risk quotients were employed to assess the chronic risk to aquatic organisms. Chlorpyrifos, atrazine, profenofos, and chlorfenvinphos were the main chemicals found in surface water. The concentrations were highest near the Builpela dam (0.413μg/L, 2.927μg/L, 0.304μg/L, 0.692μg/L, 0.073μg/L, 0.290μg/L, 0.06μg/L, and absent in the Libga dam). In the sediment, the organophosphates pyrimiphos-methyl and chlorpyrifos were found at high concentrations. They were found in higher quantities in the Libga dam (0.554mg/kg and 0.052mg/kg, respectively) and Builpela dam (0.051mg/kg and 0.043mg/kg, respectively). For organochlorines, p,p'-DDE and p,p'-DDD were the main residues detected at high concentrations. However, concentrations were higher for p,p'-DDD at Builpela than for p,p'-DDE. Additionally, high concentrations of atrazine were detected in this study. The toxic units showed a high acute risk for organisms that live in sediment as a result of chlorpyrifosfos and chlorfenvinphos residues. Similarly, pirimiphos-methyl and chlorfenvinphos, followed by chlorpyrifos, contributed to high acute risk in aquatic invertebrates. Risk quotients showed that both dams had a high long-term risk for aquatic life; however, the risk was higher at the Builpela dam due to Pirimiphos-methyl and Chlorfenvinphos. Ghana's pesticide regulations are less comprehensive and enforcement is often weaker in protecting aquatic organisms. It is recommended to enforce strict limits on pesticide residues. Additionally, there is a need to regularly review and update these regulations based on new scientific data to protect aquatic ecosystems.

Ecological impacts and management strategies of pesticide pollution on aquatic life and human beings

Pesticide contamination has become a global concern. Pesticides can sorb onto suspended particles and deposit into the sedimentary layers of aquatic environments, resulting in ecosystem degradation, pollution, and diseases. Pesticides impact the behavior of aquatic environments by contaminating organic matter in water, which serves as the primary food source for aquatic food webs. Pesticide residues can increase ammonium, nitrite, nitrate, and sulfate in aquatic systems; thus, threatening ecological environment and human health. Several physical, chemical, and biological methodologies have been implemented to effectively remove pesticide traces from aquatic environments. The present review highlights the potential consequences of pesticide exposure on fish and humans, focusing on the (epi)genetic alterations affecting growth, behavior, and immune system. Mitigation strategies (e.g., bioremediation) to prevent/minimize the detrimental impacts of pesticides are also discussed. This review aims to shed light on the awareness in reducing the risk of water pollution for safe and sustainable pesticide management.

Bioremediation potential of microalgae for sustainable soil treatment in India: A comprehensive review on heavy metal and pesticide contaminant removal

The escalating environmental concerns arising from soils contamination with heavy metals (HMs) and pesticides (PSTs) necessitate the development of sustainable and effective remediation strategies. These contaminants, known for their carcinogenic properties and toxicity even at small amounts, pose significant threats to both environmental ecology and human health. While various chemical and physical treatments are employed globally, their acceptance is often hindered by prolonged remediation times, high costs, and inefficacy in areas with exceptionally high pollutant concentrations. A promising emerging trend in addressing this issue is the utilization of microalgae for bioremediation. Bioremediation, particularly through microalgae, presents numerous benefits such as high efficiency, low cost, easy accessibility and an eco-friendly nature. This approach has gained widespread use in remediating HM and PST pollution, especially in large areas. This comprehensive review systematically explores the bioremediation potential of microalgae, shedding light on their application in mitigating soil pollutants. The paper summarizes the mechanisms by which microalgae remediate HMs and PSTs and considers various factors influencing the process, such as pH, temperature, pollutant concentration, co-existing pollutants, time of exposure, nutrient availability, and light intensity. Additionally, the review delves into the response and tolerance of various microalgae strains to these contaminants, along with their bioaccumulation capabilities. Challenges and future prospects in the microalgal bioremediation of pollutants are also discussed. Overall, the aim is to offer valuable insights to facilitate the future development of commercially viable and efficient microalgae-based solutions for pollutant bioremediation.

Diffusion of organochlorine (OCPs) and cypermethrin pesticides from rohu (Labeo rohita) internal organs to edible tissues during ice storage: a threat to human health

The migration of organochlorine pesticides (OCPs) and cypermethrin residues from internal organs to edible tissues of ice-held Labeo rohita (rohu) was investigated in this study. The liver (246 µg/kg) had the highest level of ∑OCP residues, followed by the gills (226 µg/kg), intestine (167 µg/kg), and muscle tissue (54 µg/kg). The predominant OCPs in the liver and gut were endosulfan (53-66 µg/kg), endrin (45-53 µg/kg), and dichloro-diphenyl-trichloroethane (DDT; 26-35 µg/kg). The ∑OCP residues in muscle increased to 152 µg/kg when the entire rohu was stored in ice, but they decreased to 129 µg/kg in gill tissues. On days 5 and 9, the total OCPs in the liver increased to 317 µg/kg and 933 µg/kg, respectively. Beyond day 5 of storage, total internal organ disintegration had led to an abnormal increase in OCP residues of liver-like mass. Despite a threefold increase in overall OCP residues by day 9, accumulation of benzene hexachloride (BHC) and heptachlor was sixfold, endrin and DDT were fourfold, aldrin was threefold, and endosulfan and cypermethrin were both twofold. Endosulfan, DDT, endrin, and heptachlor were similarly lost in the gills at a rate of 40%, while aldrin and BHC were also lost at 60 and 30%, respectively. The accumulation of OCP residues in tissues has been attributed to particular types of fatty acid derivatives. The study concluded that while pesticide diffusion to edible tissues can occur during ice storage, the levels observed were well below the allowable limit for endosulfan, endrin, and DDT.

Risk surveillance with spatial distribution of Organochlorine Pesticides (OCPs) from sedimentary samples of Chenab River

A pioneering study employed a holistic geostatistical approach to predict the spatial variability of a non sampled area in the Chenab River, Pakistan, using kriging interpolation for organochlorine pesticide (OCP)-polluted risk zones. The Present research intended to investigate the carcinogenic and non-carcinogenic human health risks, contamination levels, and spatial variation of OCPs in the Chenab River, Pakistan. The residual OCP content in sediment samples (n = 120) ranged from 0.056 to 32.14 ng/g. DDE and α-HCH were prevalent among all the samples analyzed, with mean concentrations of 15.84 ± 8.02 and 12.45 ± 6.72 ng/g, respectively. The order of magnitude of OCPs in sediment samples was DDTs > α-HCH > chlorothalonil > heptachlor > endosulfan > aldrin > dieldrin. The findings of the single (SPI) and Nemerow (Nel) pollution index of α-HCH, heptachlor, and aldrin depicted the Chenab River as a serious pollution risk zone. The outcomes of the Pearson correlation coefficient analysis represent the positive correlation among all OCPs, revealing the common origin. Distribution trends showed substantially higher (p < 0.05) contents of analyzed OCPs along the downstream zone. With regards to USEPA human health hazard assessment model, the estimated non-carcinogenic (ΣHI) and non-carcinogenic (ΣTCR) risk ranged from 1.1 × 10-5 to 1.0 × 10-1, 4.0 × 10-8 to 3.2 × 10-4 respectively. TCR >10-4 illustrated a substantial cancer health risk posed by α-HCH, heptachlor, aldrin, and dieldrin in the downstream zone. We recommend the urgent cessation of the ongoing discharge of OCPs into the Chenab River, which needs to be highlighted owing to the significant cancer risk to public health to ensure the good health and wellbeings.

De-novo exposure assessment of heavy metals in commercially important fresh and dried seafood: Safe for human consumption

The heavy metals (HMs) in seafood are alarming due to their biomagnification in the food chain. The concentrations of As, Cd, Hg, Pb, Cr, and Ni in both fresh and dried fish were quantified, and the potential exposure and safe intake levels for human consumption were assessed by the European Commission (EC) and the Food Safety Standard Authority of India (FSSAI). HMs concentrations ranged from 0.003 mg/kg (Cr) to 2.08 mg/kg for (As) and 0.007 mg/kg (Hg) to 2.76 mg/kg (As). Cd, Hg, and Pb levels in fresh and dried fish were below the maximum residue limits (MRLs) set by the EC and FSSAI, which were 0.1 mg/kg, 0.5 mg/kg, and 0.3 mg/kg, respectively. Cr and As concentrations were also below the MRLs of 12 mg/kg and 76 mg/kg for aquatic products specified by FSSAI. The concentration of HMs in fresh and dried fish was found in the order of As > Cr > Ni > Pb > Cd > Hg and As > Cd > Cr > Ni > Pb > Hg, while the fresh and dried fishes contained HMs in the following order: E. areolatus > S. longiceps > L.lentjen > S. barracuda > E. affinis > S. javus and DA > DS > DR > DB > DSF. The metal pollution index (MPI) validates seafood is HMs free, while the single (Pi) and Nemerow integrated pollution index (Pnw) indicate that concentrations of Cd and As in fresh and dried fish have exceeded the threshold value. The target hazard quotient (THQ<1), hazard index (HI < 1), and target cancer risk (TCR<10-4) indicate that there are no non-carcinogenic and carcinogenic risks through the consumption of seafood and seafood products collected from the Tuticorin coast and marketed at the domestic and international levels. The preliminary findings emphasize the importance of formulating domestic legislation/government initiatives to promote seafood and its consumption. The attainment of this objective shall be facilitated by examining the levels of persistent organic pollutants (POPs) in seafood and evaluating its potential risk to consumers.

Pesticides in sediments from Magdalena River, Colombia, are linked to reproductive toxicity on Caenorhabditis elegans

Pesticides are prevalent pollutants found in river sediments in agricultural regions worldwide, leading to environmental pollution and toxic effects on biota. In this study, twenty sediment samples were collected from the Magdalena River in Colombia and analyzed for forty pesticides. Methanolic extracts of the sediments were used to expose Caenorhabditis elegans for 24 h, evaluating the effects on its reproduction. The most abundant pesticides found in Magdalena River sediments were atrazine, bromacil, DDE, and chlorpyrifos. The concentrations of DDE and the sum of DDD, DDE, and DDT were above the Threshold Effect Concentration (TEC) values for freshwater sediments, indicating potential effects on aquatic organisms. The ratios of DDT/(DDE + DDD) and DDD/DDE suggest historical contributions of DDT and degradation under aerobic conditions. Several sampling sites displayed a moderate toxicity risk to biota, as calculated by the sediment quality guideline quotient (SQGQ). Nematode brood size was reduced by up to 37% after sediment extract exposure. The presence of chlordane, DDT-related compounds, and chlorpyrifos in Magdalena River sediments was associated with reproductive toxicity among C. elegans.

Pesticides in the hydrogeo-environment: a review of contaminant prevalence, source and mobilisation in India

Chemical pesticides in the hydrogeological system are a global concern as they pose a severe threat to humans and other organisms. In agriculture, around 4.12 million tonnes of pesticides were used globally in 2018, which is 50% more than in the 1990s. Various pesticides detected in the hydrogeological system of India since the 1990s have been documented and reviewed to understand the prevalence, source, history and degradation pathways. This review contributes to a better understanding of existing pesticide pollution and the state of hydrogeological resource deterioration. Small to excess levels of pesticide residues were detected in groundwater, surface water, soil, and sediments. Pesticides that were most commonly and predominantly found in the hydrogeological system were HCHs, DDTs, endosulfan, heptachlor, drins (aldrin, dieldrin, endrin), chlordane etc. β and γ-HCH isomers among HCHs, whereas p,p'-DDT and p,p'-DDE among the DDTs were detected most prevalently. In many regions, pesticide residue levels in water have exceeded the maximum residue limits of WHO and BIS, while those in soils and sediments have exceeded the threshold effect level and probable effect level. Higher pesticide residues were detected in the water resources of rural agricultural areas compared to peri-urban or urban areas. A positive correlation of pesticide residues between water resources and soil has been observed in some regions, suggesting a similar contamination source. Diagnostic ratios of pesticides reveal their source, history and degradation pathways. Diagnostic ratios observed in various studies conducted in India suggest historical as well as recent use of banned pesticides. Strengthening current policies and regulations, monitoring pesticide use, changes in pesticide application practices, awareness among farmers, and the use of prominent removal techniques are necessary to tackle pesticide contamination in India.

Pesticide pestilence: Global scenario and recent advances in detection and degradation methods

Increased anthropogenic activities are confronted as the main cause for rising environmental and health concerns globally, presenting an indisputable threat to both environment and human well-being. Modern-day industrialization has given rise to a cascade of concurrent environmental and health challenges. The global human population is growing at an alarming rate, posing tremendous pressure on future food security, and healthy and environmentally sustainable diets for all. To feed all, the global food production needs to increase by 50% by 2050, but this increase has to occur from the limited arable land, and under the present-day climate variabilities. Pesticides have become an integral component of contemporary agricultural system, safeguarding crops from pests and diseases and their use must be reduce to fulfill the SDG (Sustainable Development Goals) agenda . However, their indiscriminate use, lengthy half-lives, and high persistence in soil and aquatic ecosystems have impacted global sustainability, overshot the planetary boundaries and damaged the pure sources of life with severe and negative impacts on environmental and human health. Here in this review, we have provided an overview of the background of pesticide use and pollution status and action strategies of top pesticide-using nations. Additionally, we have summarized biosensor-based methodologies for the rapid detection of pesticide residue. Finally, omics-based approaches and their role in pesticide mitigation and sustainable development have been discussed qualitatively. The main aim of this review is to provide the scientific facts for pesticide management and application and to provide a clean, green, and sustainable environment for future generations.

Toxicological effect of endocrine disrupting insecticide (deltamethrin) on enzymatical, haematological and histopathological changes in the freshwater iridescent shark, Pangasius hypothalamus

This study investigated the deltamethrin (DMN) induced harmful effects on Pangasius hypophthalmus using enzymatic activity, haematological, and histopathological changes. LC₅₀ value was 0.021mg/L at 96h, and sublethal toxicity was tested for 45 days at two `concentrations (i.e., 1/5^th and 1/10^th of LC₅₀). Haematological parameters and enzymatic activities significantly changed between DMN-exposed and control groups (p<0.05). Histopathologically, both DMN doses induced liver hyperemia, hepatic cell rupture, necrosis, hypertrepheoid bile duct, shifting nuclei, vascular haemorrhage, and hepatocyte degeneration, while in gill, secondary lamellae destruction, a fusion of adjacent gill lamellae, hypertrophy, hyperplasia, adhesion, and fusion were noticed. Kidney developed melanomacrophages, increased periglomerular and peritubular space, vacuolation, decreased glomerulus, hyaline droplets in tubular cells, loss of tubular epithelium, distal convoluted segment hypertrophy, and granular layer in brain pyramid and Purkinje cell nucleus. But, limiting pesticide impacts on freshwater fish and their habitat requires a holistic, cradle-to-grave approach and toxicological studies.

Ecological risk assessment of aquatic organisms induced by heavy metals in the estuarine waters of the Pearl River

With the rapid economic development of China's coastal areas and the growth of industry and population, the problem of heavy metal contamination in estuarine waters is increasing in sensitivity and seriousness. In order to accurately and quantitatively describe the current status of heavy metal contamination and identify sensitive aquatic organisms with high ecological risks, five heavy metals in eight estuaries of the Pearl River were monitored at monthly intervals from January to December in 2020, and the ecological risks of aquatic organisms induced by heavy metals were evaluated using Risk quotients (RQ) and species sensitivity distributions (SSD) methods. The results showed that the concentrations of As, Cu, Pb, Hg and Zn in estuaries of the Pearl River were (0.65-9.25) μg/L, (0.07-11.57) μg/L, (0.05-9.09) μg/L, (< 0.40) μg/L and (0.67-86.12) μg/L, respectively. With the exception of Hg in Jiaomen water, the other heavy metals in each sampling site met or exceed the water quality standard of Grade II. The aquatic ecological risks of As, Pb and Hg were generally low in the waters of the Pearl River estuary, but individual aquatic organisms are subject to elevated ecological risks due to Cu and Zn. The content of Zn has a lethal effect on the crustaceans Temora Stylifera, and the content of Cu has a serious impact on the mollusks Corbicula Fluminea and has a certain impact on the crustaceans Corophium sp. and the fish Sparus aurata. Heavy metal levels and joint ecological risks (msPAF) in the Humen, Jiaomen, Hongqimen, and Hengmen estuaries were slightly higher than in other estuaries, and the Yamen estuary had the lowest contration of heavy metals and ecological risk. Research findings can serve as a basis for formulating water quality standards for heavy metals and for protecting aquatic biodiversity in the Pearl River Estuary.

Sediment-water partitioning and risk assessment of organochlorine pesticides along the urban, peri-urban and rural transects of Krishna River Basin, Peninsular India

Organochlorine pesticides (OCPs) were widely used in the past for pest control in agricultural lands and vector control programs in India. Due to their persistence and toxic impacts, we have quantified twenty OCPs in surface water, groundwater, and surface sediment samples along the Krishna River Basin (KRB), flowing through Peninsular India. Samples were collected along the urban, peri-urban, and rural transects of the KRB to understand the relation between the occurrence of pesticidal organochlorine pollutants based on the land use and land cover (LULC) and asses potential risk. Diagnostic ratios revealed ongoing Lindane usage in rural and peri-urban transects. On the contrary, the urban transect of the Musi River (MR) showed fresh inputs of technical HCH. The ratios of (p,p'-DDE+ p,p'-DDD)/ΣDDT >0.5 and α/β-Endosulfan < 2.33 for most of the sites across the three transects for surface water, groundwater, and sediment indicate past DDT and Endosulfan usage across KRB. Excluding p,p'-DDE, and heptachlor in most of the sites, the logK_OC' was higher than logK_OC for other OCPs in the urban transect. However, for all the OCPs, the logK_OC' was lower than logK_OC in the peri-urban and rural transects of KRB thereby indicating that riverine sediment is acting as a sink for OCPs. The Krishna River annually transport about 0.24 tons HCH, 0.11 tons of DDT and 0.1 tons of Endosulfan. Despite having low water discharge, the compound-specific fluxes of the Wyra river are higher than the other two tributaries. Ecotoxicological risk assessment based on the Hazard Quotient suggested DDT pose higher risks to scud (zooplankton) and dinoflagellate and diatom (phytoplankton) whereas Endosulfan poses a threat to Bluegill (fish).

Comparison of the drinking water standard for pesticides of the Brazil with other countries

The objective was to compare the types and concentrations of pesticides allowed in the water potability standard for human supply in Brazil with other countries considered to be the largest consumers of pesticides in dollars invested in purchase/trade. This is a descriptive and documentary study, with data collection in regulations available in official government websites in Brazil, USA, China, Japan, France, Germany, Canada, Argentina, India, Italy, and World Health Organization (WHO). Since Germany, France and Italy are part of the European Union (EU), the legislative resolution of the European Parliament was adopted. Pesticides number and maximum permitted values (MPV) differ between the countries and WHO. In the Brazilian ordinance there are forty pesticides, a number like the USA, Canada, China, and WHO, but that represents only 8% of the total pesticides registered for agricultural use in Brazil. When comparing the ordinance of Brazil with EU the values are only the same for Aldrin + Dieldrin. For other, amounts between 2 and 5000 times more are allowed in Brazil. Brazilian regulations do not establish a total value for the mixture of pesticides in water, only individual limits, which together can reach 1677.13 μg/L, while in EU standards it is only 0.5 μg/L. The study showed discrepancies of the pesticides allowed in water potability standard of the Brazil with other countries, but features 12 pesticides with the same concentrations as WHO guidelines, thus, a worldwide standardization in water potability regulations is necessary to promote health and reducing risk of exposure.

Computer-aided toxicity prediction and potential risk assessment of two novel neonicotinoids, paichongding and cycloxaprid, to hydrobionts

Paichongding (IPP) and cycloxaprid (CYC) have been effectively used as the alternative products of imidacloprid (IMI) against IMI-resistant insects and exhibit a great market potential. However, risk assessment of IPP and CYC for non-target organisms, especially ecological risk assessment for non-target aquatic organisms, is still lacking. Here, we predicted the toxicity and potential risks of IPP, CYC, and their transformation products (TPs) to hydrobionts. The results indicated that IPP and CYC could generate 428 and 113 TPs, respectively, via aerobic microbial transformation. Nearly half of the IPP TPs and nearly 41 % of the CYC TPs exhibited high or moderate toxicity to Daphnia or fish. Moreover, we found that IPP, CYC, and 80 TPs of them posed potential risks to aquatic ecosystems. Almost all harmful TPs contained a 6-chloropyridine ring structure, suggesting that this structure may be associated with the strong toxicity of these TPs to aquatic organisms, and these TPs (IPP-TP2 or CYC-TP2, IPP-TP197 or CYC-TP71, IPP-TP198 or CYC-TP72, and IPP-TP212 or CYC-TP80) may appear in aquatic environments as final products. The risks posed by these TPs to aquatic ecosystems require more attention. This study provides insights into the toxicity and ecological risks of IPP and CYC.

Risk assessment of persistent pesticide pollution: Development of an indicator integrating site-specific characteristics

Detection of high pesticide concentrations in sediments and water often leads to prioritizing a site as being 'at risk'. However, the risk does not depend on pesticide concentration alone, but on other site-specific characteristics also. We developed an indicator that identifies the 'Level of Concern' by integrating five such characteristics: (i) pesticide concentrations in surface and groundwater causing risks to ecological health (ii) impacts on human health, (iii) water scarcity, (iv) agricultural production, and (v) biodiversity richness. We applied this framework in an agricultural region of the Lower Ganges Basin in West Bengal, India. We measured concentrations of selected organochlorine pesticides (OCPs) in surface and groundwater within an 8 km² area in 2019. Of 20 banned and restricted OCPs, 11 were detected as causing high risk to ecological health and 10 at concentrations above the Accepted Carcinogenic Risk Limit (ACRL) for humans. In the pre-monsoon, the mean concentrations of ΣOCPs in groundwater and surface water were 126.9 ng/L and 104 ng/L, in the monsoon they were 144.7 ng/L and 138 ng/L, and in the post-monsoon 122.1 ng/L and 147 ng/L respectively. In groundwater, no significant seasonal difference was observed in most pesticides. In the surface water, 7 pesticides were significantly higher in the monsoon and post-monsoon, which may be attributed to increased runoff as well as post monsoon application of OCPs. In September 2022 we again measured OCP concentrations in surface water and sediment. The mean concentration of 14 of the 20 measured OCPs were found to be significantly lower in the post-pandemic period compared to the pre-pandemic time. These lower pesticide concentrations may indicate a reduced use of OCPs in agricultural practices during the pandemic. This area was identified as being at the highest Level of Concern, even though the OCP concentrations alone conformed to general guidelines.

Distribution and risk assessment of pesticide residues in sediment samples from river Ganga, India

Indiscriminate use of pesticides leads to their entry in to the bottom sediments, where they are absorbed in the sediment's particle and thus, may become the consistent source of aquatic pollution. The present work was carried out to evaluate pesticide residues in the sediment samples and associated human health risk of commonly used pesticides along the basin of river Ganga. Total of 16 pesticides were analyzed along three stretches of river Ganga. The concentration of pesticides in the upper stretch ranged from ND to 0.103 μg/kg, in the middle stretch ND to 0.112 μg/kg, and in the lower stretch ND to 0.105 μg/kg. Strong positive correlation was found between total organic carbon and total pesticide residues in sediment samples. Carcinogenic and non-carcinogenic values were estimated below the threshold limit suggesting no associated risk. Risks associated with the inhalation route of exposure were found to be higher than the dermal and ingestion routes. Children were found at higher risk at each site from multiple routes of exposure than adult population groups. Toxic unit values were found to be below the threshold value suggesting no risk associated with exposure of pesticides from sediments. However, long term effects on ecological quality due to consistent pesticide exposure must not be ignored. Therefore, the present study focuses on concrete efforts like lowering the irrational used of pesticides, tapping of agricultural and domestic drains, advice to farmers for appropriate use of pesticide doses, to reduce the threat of pesticide pollution in the river system and possible human health risk.

Ecological risk assessment of pesticides in sediments of Pampean streams, Argentina

After their application in agricultural areas, pesticides are dispersed throughout the environment, causing contamination problems. In Argentina, the main promoter of transgenic biotechnology in the region, the total consumption of agrochemicals has increased significantly in recent years. Most chemicals dumped near surface waters eventually end up in bottom sediments and can be toxic to the organisms that live there. However, published data on the mixing of pesticides in this compartment is still scarce. The objective of this work was to detect and quantify pesticide residues in the sediment of rural streams in the Pampas region and to carry out acute and chronic risk assessment in these aquatic ecosystems. The study area comprises the mountainous system of Tandilia, located in one of the most productive agricultural areas in the country. The concentration of atrazine, acetochlor, chlorpyrifos, cypermethrin, and 2,4-D in the sediment of four rural streams was determined in three different seasons, and the toxic units (TU) and the risk ratios (RQ) were calculated. All the compounds analyzed were detected in most of the sampling seasons and study sites, at concentrations higher than those established in the national and international quality guidelines for the protection of aquatic biota in surface waters and for human consumption. Chlorpyrifos, cypermethrin, and acetochlor were the main pesticides contributing to the TU and RQ values, representing a medium or high ecological risk in most of the sites. Therefore, the evaluation of these pesticides in the bottom sediments could be a decisive factor in assessing the risk to the aquatic environment.

Accumulation of Plastics and Trace Elements in the Mangrove Forests of Bima City Bay, Indonesia

Pollution with microplastics (MPs), nanoplastics (NPs) and trace elements (TEs) remains a considerable threat for mangrove biomes due to their capability to capture pollutants suspended in the water. This study investigated the abundance and composition of plastics and TEs contained in the soil and pneumatophores of Avicennia alba sampled in experimental areas (hotel, market, river mouth, port, and rural areas) differentiated in anthropopressure, located in Bima Bay, Indonesia. Polymers were extracted and analyzed with the use of a modified sediment isolation method and Fourier transform infrared spectroscopy. Trace elements were detected by inductively coupled plasma optical emission spectrometry. The lowest and highest quantities of MPs in soil were recorded in rural and hotel areas, respectively. The rural site was characterized by distinct MP composition. The amounts of sediment-trapped MPs in the tested localities should be considered as high, and the recognized polymers partly corresponded with local human activity. Concentrations of seven plastic types found in plant tissues did not entirely reflect sediment pollution with nine types, suggesting a selective accumulation (particularly of polyamides and vinylidene chloride) and substance migration from other areas. Very low concentrations of non-biogenic TEs were observed, both in sediments and pneumatophores. The results highlight the relevance of environmental contamination with plastics.

Tissue distribution, dietary intake and human health risk assessment of organophosphate pesticides in common fish species from South African estuaries

This study assessed the tissue distribution, dietary intake, and potential health risks of eight OPPs in Pomadasys commersonnii (Spotted grunter) and Mugil cephalus (Flathead mullet) from the Sundays and Swartkops estuaries in South Africa. The highest concentration in fish tissues was found in muscles of M. cephalus (178 ± 80.4 ng/g ww) and P. commersonnii (591 ± 280 ng/g ww) from Sundays Estuary. The ∑₆OPPs concentration in muscles from both fish species was higher in muscles than in the gills with fenitrothion dominating the distribution profile. Results from the path analysis indicate that lipid, weights, and length of the fish species do not influence the concentration of OPPs in the studied fish species. The calculated hazard ratios, which represent the non-carcinogenic risks, were less than one for all OPPs, indicating that the concentration of OPPs detected in fish muscles had negligible consequences on human health.

Occurrence, spatio-temporal distribution, and human health risk assessment of pesticides in fish along the Ayuquila-Armería River, Mexico

Pesticide usage has contributed to increasing food production; it has also caused them to be found in ecosystems inducing adverse effects on biota. Fish are the most abundant and diverse vertebrates in the world and are of great importance both economically and ecologically. Some fishes are indicators of the environmental quality of aquatic ecosystems and provide insight as to how pollutants might influence public health. The tilapias species can be considered biomonitors because they present little displacement representing the contamination level of a site. This study aimed at three goals: (1) to determine the concentration of 20 pesticides in tilapia muscle in the Ayuquila-Armería basin, (2) to describe the spatiotemporal variation of analytes and (3) to evaluate the risk of consuming contaminated fish. The presence of 11 pesticides was determined. Ametrine, glyphosate and malathion concentrations showed significant differences by season. The risk assessment showed that the consumption of tilapia muscle from the Ayuquila-Armería basin does not represent a risk for the population. Diazinon concentrations were relatively low compared to the other pesticides concentrations, but its toxic characteristics were the ones that most negatively influenced the risk assessment. The results obtained are relevant from the social and economic points of view.

Bioaccumulation of organochlorine pesticide residues (OCPs) at different growth stages of pacific white leg shrimp (Penaeus vannamei): First report on ecotoxicological and human health risk assessment

Pesticide residues (PRs) in farmed shrimps are concerning food safety risks. Globally, India is a major exporter of pacific white leg shrimp (P. vannamei). This study was undertaken to analyze PRs in the water, sediments, shrimps, and feed at different growth stages to evaluate the ecotoxicological and human health risks. PRs in the seawater and sediments ranged from not detected (ND) to 0.027 μg/L and 0.006-12.39 μg/kg, and the concentrations were within the maximum residual limits (MRLs) and sediment quality guidelines prescribed by the World Health Organization and Canadian Environment Guidelines, respectively. PRs in shrimps at three growth stages viz. Postlarvae, juvenile, and adults, ranged from ND to 0.522 μg/kg, below the MRLs set by Codex Alimentarius Commission and European Commission. Most of the PRs in water, sediments, and shrimps did not vary significantly (p > 0.05) from days of culture (DOC-01) to DOC-90. The hazard quotient (HQ) and hazard ratio (HR) were found to be < 1, indicating that consumption of shrimps has no noncarcinogenic and carcinogenic risks. PRs in shrimp feed ranged from ND to 0.777 μg/kg and were found to be below the MRLs set by EC, which confirms that the feed fed is safe for aquaculture practices and does not biomagnify in animals. The risk quotient (RQ) and toxic unit (TU) ranged from insignificant level (ISL) to 0.509 and ISL to 0.022, indicating that PRs do not pose acute and chronic ecotoxicity to aquatic organisms. The study suggested no health risk due to PRs in shrimps cultured in India and exported to the USA, China, and Japan. However, regular monitoring of PRs is recommended to maintain a sustainable ecosystem.

Legacy and new chlorinated persistent organic pollutants in the rivers of south India: Occurrences, sources, variations before and after the outbreak of the COVID-19 pandemic

During pre-pandemic time, organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) were investigated in the surface water of Periyar River (PR) and Bharathappuzha River (BR) in Ernakulam and Malappuram districts of Kerala, respectively and Adyar River (AR) and Cooum River (CR) in Chennai district of Tamil Nadu. After the outbreak of COVID-19 pandemic, variation in OCPs and PCBs were evaluated for AR and CR. Dominance of β-HCH and γ-HCH in south Indian rivers indicate historical use of technical HCH and ongoing use of Lindane, respectively. In > 90 % sites, p,p'-DDT/ p,p'-DDE ratio was < 1, indicating past DDT usage. However during the outbreak of the COVID-19 pandemic, elevated p,p'-DDT in AR and CR reflects localized use of DDT possibly for vector control. Similarly, during the first wave of pandemic, over a 100-fold increase in PCB-52 in these rivers of Chennai mostly via surface run-off and atmospheric deposition can be reasoned with open burning of dumped waste including added waste plastic in the solid waste stream. On contrary, a significant (p < 0.05) decline of dioxin-like PCBs level, suggests lesser combustion related activities by the formal and informal industrial sectors after the lockdown phase in Tamil Nadu. Eco-toxicological risk assessment indicated a higher risk for edible fish in PR due to endosulfan.

Accumulation potential of heavy metals at different growth stages of Pacific white leg shrimp, Penaeus vannamei farmed along the Southeast coast of Peninsular India: A report on ecotoxicology and human health risk assessment

This study compared the heavy metal concentration in water, sediment, and shrimp at different growth stages of culture and subsequently evaluated the ecotoxicological and human health risk status. Total trace element concentration in the water, sediment and shrimp ranged from not detected (ND) (Hg) to 91.05 (Fe) μg/L, 0.01 (Hg) to 19, 246.33 (Fe) mg/kg, and ND (Hg) to 13.98 (Fe) mg/kg, respectively. Toxic metals such as, Cd, Hg, and Pb in shrimps ranged from ND to 2.11 mg/kg, ND to 0.158 mg/kg, ND to 0.088 mg/kg, and ND to 0.469 mg/kg, respectively. Toxic heavy metals at all the growth stages of shrimps (days of culture (DOC)-01 to DOC-90) were found below the maximum residual limit (MRL) of 0.5 mg/kg set by the European Commission (EC). Similarly, Cu, Zn, and As concentrations in shrimp were also far below the MRLs of 30 mg/kg, 100 mg/kg, and 76 mg/kg set by the World Health Organization and Food Safety and Standard Authority of India, respectively. The concentration of heavy metals increased from DOC-01 to DOC-90 and was positively correlated with the length and weight of the shrimps (p < 0.05). The risk assessment was estimated for both Indians and Americans and found no carcinogenic (lifetime cancer risk (LCR) < 10^-4) and non-carcinogenic (THQ and TTHQ<1) health risks through consumption of shrimp cultured in this region. The hazard quotient (HQ_dermal < 1), hazard index (HI < 1), and LCR (<10^-4) values of the heavy metals indicated that the dermal absorption might not be a concern for the local fishermen and marine fish/shrimp farmworkers. Water and sediment quality indices were applied to assess the surface water and sediment quality, and their results were found nil to low levels of heavy metal contamination at all the sampling sites. All heavy metals studied in sediments were < effect range low (ERL) and < threshold effect level (TEL), indicating no adverse biological effects on aquatic organisms. Therefore, regular monitoring of the shrimp aquaculture system throughout the crop will provide evidence of heavy metals bioaccumulation in shrimps. This research will provide baseline data to help farmers establish the optimal aquaculture practices and regulatory authorities to formulate legislation and strategies to reduce heavy metal biomagnification in shrimps from farm to fork.

Investigating a broad range of emerging contaminants in a set of anthropogenically impacted environmental compartments

Environmental compartments are repositories of probably thousands of emerging contaminants (ECs) released along with treated/untreated wastewater. Despite extensive studies on the detection of ECs in surface water, other environmental compartments such as sediments and groundwater are yet to be thoroughly investigated. To assess the heavy anthropogenic impact on the environment, 24 environmental samples comprising of surface water, sediment and groundwater collected from the Yamuna River basin of India were analyzed via target and suspect screening. The surface water and sediment samples were collected from upstream and downstream of densely populated cities and towns situated along the heavily contaminated river Yamuna. The groundwater samples were collected from shallow drinking water wells of the catchment. Liquid chromatography tandem mass-spectroscopy was used to quantify 10 widely consumed pharmaceuticals in the samples. The study also analyzed the potential health hazards posed by the quantified contaminants. In order to evaluate further, the surface water and groundwater samples were subjected to high resolution mass spectrometry (HRMS) screening against a library resulting in a list of 450 ECs in the surface water and 309 ECs in the groundwater. Agricultural chemicals and pharmaceuticals found abundantly in the samples and half of whom were reported first time. The risk quotient was calculated to assess the potential hazard of the target analytes.

Effect of household culinary processes on organochlorine pesticide residues (OCPs) in the seafood (Penaeus vannamei) and its associated human health risk assessment: Our vision and future scope

Food safety is crucial in today's competitive trading market, as it directly affects human health and promotes seafood exports. The effects of thermal processing (boiling, frying, grilling, and microwave cooking) on pesticide residues (PR) in P. vannamei were assessed. The PR in raw and processed shrimp ranged from 0.007 to 0.703 μg/kg for uncooked/raw, not detected (ND) to 0.917 μg/kg for boiled, ND to 0.506 μg/kg for fried, ND to 0.573 μg/kg for grilled and ND to 0.514 μg/kg for microwave cooked shrimps. The Endrin, endosulfan sulfate, and heptachlor were predominant PR found in the raw and processed shrimp. The PR content in raw and cooked shrimps were below the maximum residue limits (MRL) set by the Codex Alimentarius Commission (2021) and the European Commission (86/363/1986 and 57/2007). The estimated daily intake (EDI) of PR from raw and processed shrimps were below the ADI prescribed by CAC. The hazard quotient (HQ) and hazard ratio (HR) values were <1, indicating no non-carcinogenic or carcinogenic health implications through shrimp consumption. The estimated maximum allowable shrimp consumption rate (CRlim) suggests an adult can eat >100 shrimp meals/month, which is over the USEPA's (2000)recommendation of >16 meals/month without health issues. The Effect of thermal processing was detected in the following order: boiling < grilling < frying < microwave cooking. The processing factor (PF < 0.7), paired t-test (t < 0.05), Tukey post hoc (p < 0.05) test, Bray-Curtis similarity index, and matrix plot exhibited that all the four thermal processing methods have a considerable impact on pesticides in the processed shrimps. But frying (59.4%) and microwave cooking (60.3%) reduced PR far beyond boiling (48.8%) and grilling (51.3%). Hence, we recommend frying and microwave processing are better methods for minimizing PR in seafood than boiling or grilling.

Distribution and ecological risk assessment of heavy metals using geochemical normalization factors in the aquatic sediments

Thamirabharani river acquires a noticeable quantity of sewage and agriculture waste from local inhabitants. The distribution of heavy metals in the surface sediments of the Thamirabharani river was analyzed using Inductively Coupled Plasma- Mass Spectrometry (ICP-MS) to study the ecological risks. The heavy metal concentrations in the sediments ranged from 0.098 ± 0.03(Cd) to 159.181 ± 13.36 mg kg^-1 (Fe). The Cd, Zn, Ni, Fe, and Mn concentrations in the sediments were above the US Environmental Protection Agency-Sediment Quality Guidelines. The fact that Cd, Co, and Cu concentrations at sites 4 and 5 exceeded the background values (BGVs) of 0.2, 13, and 32 mg kg^-1 suggests anthropogenic activity, notably in the downstream of the river. The sediment contaminated with Cd is more evident, particularly in the estuarine region. The potential ecological risk index (150<PERI≤300) and ecological risk co-efficient (40 < Er < 80) revealed moderate ecological risk at the estuarine region (S5). There was a moderate level of pollution in the downstream region (S4 and S5) based on a geo-accumulation index (Igeo), contamination factor (CF), pollution load index (PLI), and the moderate degree of contamination (mCd) values. According to the geochemical normalization factors, the downstream region (sites 4 and 5) was moderately polluted than the upstream region (S1 and S2), which may affect the estuarine/marine ecosystem. This information may facilitate the relevant regulatory authorities to implement the requisite stringent monitoring program in the aquatic ecosystem.

Potentially toxic elements contamination and its removal by aquatic weeds in the riverine system: A comparative approach

Thamirabarani river acquires large untreated sewage effluents from the Tirunelveli and Thoothukudi districts of South Tamil Nadu. This study examined the concentration of trace elements in water, sediment, and phytoaccumulation potential of aquatic weeds viz., A. cristata, E. crassipes, S. natans, and P. stratiotes, growing along Srivaikundam dam of Thamirabarani river. The Pb, As, Hg, Cd, and Ni concentrations in water were slightly higher than the US Food and Drug Administration (USFDA) drinking water guidelines; however, their accumulation in sediment was below WHO's sediment quality guideline. This study concludes that the phytoaccumulation factor (PAF) and translocation factor (TF) was >1 in E. crassipes and A. cristata, representing them as hyperaccumulators, suitable for phytoremediation in polluted localities. E. crassipes, A. cristata, and S. natans accumulated (100-500 fold) higher trace elements concentrations than that present in the water. Also, the concentrations of trace elements found in the aquatic weeds were below the recommended levels for the critical plant range (CRP). These selected aquatic weeds are more suitable for plant hybridization to be modified as superbug plants.

Pesticide residues in Rita rita and Cyprinus carpio from river Ganga, India, and assessment of human health risk

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Accumulation of pesticide residues in fish due to continuous use in agricultural areas along river Ganga basin.

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Residues concentrate in the humans through consumption of food from the river.

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Health impacts like non-carcinogenic (THQ) and carcinogenic (R) risks are never negligible by these residues.

Present study was carried out to determine the concentration and bioaccumulation of pesticide residues in two commonly edible fishes: bagrid fish, Rita rita and common carp, Cyprinus carpio collected from river Ganga at Narora, India. The human health risk via consumption of these fishes was also assessed. The n-hexane extract of the muscle tissues was characterized by gas chromatography coupled to mass spectrometry and quantified by electron capture detector for pesticide residues. Bioaccumulation factor (BAF) in bagrid fish for detected pesticides was found to be higher than those in common carp. Estimated daily intake (EDI) values in our study were insignificantly higher than Average daily intake (ADI) values. Target hazard quotient (THQ) via consumption of selected fishes was found to be lower than the set 1.0, inferring non-carcinogenic risk. With regard to contaminants carcinogenic effects the total risk ratio (R) values of each pesticide was found lower than threshold risk limit except of heptachlor which indicates carcinogenic risk. The results justify pesticide pollution in river Ganga at Narora and thus more attention is required in order to help improve the health status of this ecosystem and reduce contamination of fishes.

From field to plate: Agricultural pesticide presence in the guayas estuary (Ecuador) and commercial mangrove crabs

Mangroves are unique coastal ecosystems, located in tropical and subtropical regions. Yet, the functioning of these essential ecosystems is threatened by the presence of pollutants, including pesticides originating from agricultural activities. We investigated pesticide residues in the Guayas estuarine environment, since agricultural activities rapidly increased in the Guayas river basin over the past decades. A multi-residue analysis involving a selection of 88 pesticides was performed on the white meat and the hepatopancreas of the red mangrove crab (Ucides Occidentalis) at 15 sampling sites within the Guayas estuary along with water, sediment, and leaves samples. We found that 35 active compounds were present in the Guayas estuary, of which pyrimethanil was most commonly detected and had the highest concentrations in almost all compartments. Also, cadusafos was present in all studied compartments of the Guayas mangrove system and several prohibited pesticides (including carbendazim, carbofuran, and parathion) were detected. An ecotoxicological and probabilistic consumer risk assessment pointed out that current butachlor, carbendazim, and fludioxonil concentrations can cause adverse effects in aquatic organisms in the long term. Moreover, high potential acute and chronic risks of cadusafos residues on aquatic invertebrates and of diuron on algae in the Guayas wetlands were observed. Still, the exposure results indicated that the health risk for the consumers of the commercial red mangrove crab is low concerning cadusafos, chlorpyrifos, diuron, linuron, and pyrimethanil residues in crab tissues. The findings presented in this research can provide a useful basis for local water managers and environmental conservation groups to act and reduce the usage of pesticides, to avoid threatening aquatic and human health.

Increasing disease burden and use of drugs and chemicals in Bangladesh shrimp aquaculture: A potential menace to human health

Using structured surveys in 2008 and 2016, change in disease burden and use of chemical treatments in Bangladesh shrimp farm management was examined. Overall, disease burden had increased in all farms and was more polarized, with a fewer number of individual infectious diseases responsible for most disease in ponds. Farmers also reported physical deformities, nutritional deficiencies, and unknown diseases further indicating poor health of their stock. To combat the threat, more chemical treatments were used (5.2 treatments per farm in 2008 versus 28.8 in 2016), resulting in an average increase of 424% in the number of active substances entering shrimp ponds. Although there was a modest reduction in the use of antimicrobials, shrimp was being exposed to a wider range of chemicals during rearing. The subsequent concern for the environment, animal and human health demands further research to identify potential risks from residues of chemical products.

Non-Occupational Exposure to Pesticides: Experimental Approaches and Analytical Techniques (from 2019)

BACKGROUND

Pesticide residues are a threat to the health of the global population, not only to farmers, applicators, and other pesticide professionals. Humans are exposed through various routes such as food, skin, and inhalation. This study summarizes the different methods to assess and/or estimate human exposure to pesticide residues of the global population.

METHODS

A systematic search was carried out on Scopus and web of science databases of studies on human exposure to pesticide residues since 2019.

RESULTS

The methods to estimate human health risk can be categorized as direct (determining the exposure through specific biomarkers in human matrices) or indirect (determining the levels in the environment and food and estimating the occurrence). The role that analytical techniques play was analyzed. In both cases, the application of generic solvent extraction and solid-phase extraction (SPE) clean-up, followed by liquid or gas chromatography coupled to mass spectrometry, is decisive. Advances within the analytical techniques have played an unquestionable role.

CONCLUSIONS

All these studies have contributed to an important advance in the knowledge of analytical techniques for the detection of pesticide levels and the subsequent assessment of nonoccupational human exposure.

Occurrence, spatial distribution, source, and ecological risk assessment of organochlorine pesticides in Dongting Lake, China

The occurrence, distribution, sources, and ecological risks of organochlorine pesticides in Dongting Lake of China were investigated. The average concentrations of organochlorine pesticides (OCPs) in 22 surface water samples and 14 sediment samples were 90.07 ng/L and 80.65 ng/g dw, respectively. Sixteen types of OCPs, dominated by HCHs, DDTs and heptachlor, were detected in the Dongting Lake. The relationships of OCP residues between Dongting Lake and its tributary rivers have been discussed and the hydraulic connections with the Yangtze River and the Three Gorges Dam (TGD) were also considered. Results showed that the shortage of runoff, earlier dry season, and reduction of sediment deposition extremely deteriorated the hydraulic conditions, magnified the water cycle, and restrained the self-purification of OCPs. The ∑OCPs in surface water were concentrated in the inlets of Yangtze River, Lishui River, Zishui River, Yuanshui River, and Xiangjiang River. Moreover, the ∑OCPs in the outlet of the Yangtze River also maintained a high level, indicating that OCPs posed adverse effects on the Yangtze River. Risk assessments of OCPs in the surface water of Dongting Lake were estimated according to available water quality guidelines and health risk assessment models. The results indicated that OCPs in the surface water of Dongting Lake were safe for aquatic organisms and human health. In addition, sediment quality guidelines (SQGs) were also applied to evaluate the potential ecotoxicological risks of OCPs in sediments. The results presented that contaminants of γ-HCH; o,p'-DDD; and dieldrin in sediment had adverse effects on benthic organisms, indicating that fundamental solutions should be proposed to control OCP contamination in Dongting Lake.