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BACKGROUND: With over 12 000 registered mixture formulations in China, environmental risk assessment of co‐formulated pesticide mixtures to aquatic ecosystems is of increasing interest to scientists, risk assessors, and risk managers. This study proposed a pragmatic approach based on widely accepted scientific concepts and strategies. RESULTS: The proposed approach has three tiers, a preliminary Tier 0 stage, a Tier 1 stage, and a refinement stage as Tier 2, which are demonstrated with one case study. Because of the large number of co‐formulated pesticide mixtures available in China, a unique Tier 0 stage is proposed with practicable criteria to identify mixtures requiring further evaluation. For Tier‐1 assessment, exposure is assessed based on the application scheme and local scenarios in China. Hazard is evaluated using the concentration addition model as the default approach, which was developed a century ago and was adopted by the majority of the regulators globally. Given the unique characteristics of mixtures in the environment, data variability and ratio changes of active ingredients are also evaluated for hazard assessment. More accurate assessments with decreased uncertainties can be achieved by higher tier refinements in Tier‐2, such as alternative models, consideration of co‐formulants, and higher tier effect and exposure analyses. CONCLUSION: Widely accepted concepts, methodologies, and criteria should be used for aquatic risk assessment for pesticide mixtures in China. To avoid unnecessary workload and a more accurate assessment, unique perspectives such as local agricultural practice, local scenarios and a preliminary screening stage (Tier 0) should be implemented. © 2019 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

Rice-crab (Chinese mitten crab, Eriocheir sinensis) coculture system has become one of the most important agricultural activities practiced in China. However, the effect of pesticide usage on the survival and edible safety of crab species living in the coculture system has not been investigated. In the present study, we created a field simulation experiment and discovered that the amount of pesticide chlorantraniliprole (CAP) entering the rice-crab coculture system accounted for 82.22% of the total CAP content present in the spray barrel. When CAP residues found in the soil leached into nearby areas, we observed an increase in the CAP concentration in the water and sediment. Specifically, peak CAP concentration (1.35 μg/L) was detected in water within 1 day, and a steady CAP concentration in the sediment (2.55 μg/kg) was detected within 3 days. Additionally, an extensive field sampling experiment conducted in the basin of the lower reaches of the Yangtze River revealed that CAP was routinely used in rice-crab coculture systems. Although detected CAP concentrations were below 1 μg/L in ditch water and below 1 μg/kg in ditch sediment, there was still a potential risk associated with the crab growth. Importantly, there was no risk associated with crab consumption, given the low detection frequency of CAP in the collected samples. Our analysis suggests that an increase in usage ratio and a decrease in the total CAP content will likely promote safe application of CAP in the rice-crab coculture systems. • A combination of simulation and field sampling experiments were conducted. • Chlorantraniliprole was posing a risk associated with the crab growth, but no risk associated with crab consumption. • An increase in usage ratio and a decrease in the total chlorantraniliprole content was suggested. [ABSTRACT FROM AUTHOR]

This article focuses on the use and regulation of eight toxic pesticides in agricultural production in China. The pesticides are bifenthrin, chlorpyrifus, diazinon, dimethoate, methidathion, omethoate, phosmet and phosphamidon. These pesticides pose widely recognised public health risks in China. So far as we know, the article is the first article in English ever to treat these pesticides systematically from the standpoint of the regulation of risks to human beings and to the environment. Adopting perspectives from public health, economic sociology and law, the article considers the principal characteristics of these pesticides, the main health risks associated with their use in agricultural production and how these pesticides in agricultural production are currently regulated in Chinese law. It identifies a series of policy implications and makes specific policy recommendations concerning risk regulation of these eight pesticides. [ABSTRACT FROM PUBLISHER]

Residues of 14 pesticides were determined in 150 cowpea samples collected in five southern Chinese provinces in 2013 and 2014.70% samples were detected one or more residues. 61.3% samples were illegal mainly because of detection of unauthorized pesticides. 14.0% samples contained more than three pesticides. Deterministic and probabilistic methods were used to assess the chronic and acute risk of pesticides in cowpea to eight subgroups of people. Deterministic assessment showed that the estimated short-term intakes (ESTIs) of carbofuran were 1199.4%–2621.9% of the acute reference doses (ARfD) while the rates were 985.9%–4114.7% using probabilistic assessment. Probabilistic assessment showed 4.2%–7.8% subjects may suffer from unacceptable acute risk from carbofuran contaminated cowpeas from the five provinces (especially children). But undue concern is not necessary, because all the estimations are based on conservative assumption. [ABSTRACT FROM AUTHOR]

Contamination with agricultural pesticides such as dichlorodiphenyltrichloroethane (DDT) and its metabolites, dichlorodiphenyldichloroethylene (DDE) and dichlorodiphenyldichloroethane (DDD), is among several proposed stressors contributing to the global declines in amphibian populations and species biodiversity. These chemicals were examined in insects and in the muscle, liver, and eggs of rice frogs ( Rana limnocharis) from the paddy fields of an agricultural site in South China. The ΣDDT (sum of DDT, DDE, and DDD) concentrations ranged from 154 to 915, 195 to 1,400, and 165 to 1,930 ng/g lipid weight in the muscle, liver, and eggs, respectively. All the DDTs (DDT, DDE, and DDD) showed higher affinity for the liver relative to muscle tissue and can be maternally transferred to eggs in female frogs. The average biomagnification factors for DDTs ranged from 1.6 to 1.9 and 1.5 to 2.9 in female and male frogs, respectively, providing clear evidence of their biomagnification from insects to frogs. Compared with the reported DDT levels demonstrated to have toxic effects on frogs, DDTs in the present frogs are unlikely to constitute an immediate health risk. However, the adverse impacts of high DDT residues in eggs on the hatching success and their potential toxicity to the newly metamorphosed larval frogs should be assessed further. Environ. Toxicol. Chem. 2012;31:705-711. © 2011 SETAC [ABSTRACT FROM AUTHOR]

Abstract: Schizandra chinensis Baillon, or omija, is a fruit native to northeast Asia that is cultivated in South Korea and China. Fresh omija fruit has been used in beverages, traditional East Asian medicine and cosmetics because of its complex flavor and pharmacological effectiveness. The objective of this study was to analyze residue levels of 33 kinds of pesticides on fresh omija fruits and in omija juices produced in South Korea. A risk assessment of the pesticides in omija juice was conducted by calculating EDI and ADI. Most of the pesticide levels were below the LOD in fresh omija fruits. Among the detected compounds, the most frequently detected pesticide was ethoprophos. The EDIs of ethoprophos, pendimethalin and hexaconazole were 5.89E-03, 7.08E-04 and 4.73E-05, respectively. The percent of EDI to ADI of ethoprophos, pendimethalin and hexaconazole was 28.0%, 13.6% and 4.5%, respectively. The results of this research concluded that the detected pesticides are not harmful to human beings. [Copyright &y& Elsevier]

Characteristics and risk evaluation of organchlorine pesticides (OCPs) in the sediments of four lakes located in the Lake Lianhuan area were conducted to observe the risks on ecological system and identify the sources of pollutants. Measurement of eleven OCPs, four hexachlorocyclohexane (HCH) isomers (α-HCH, β-HCH, γ-HCH, δ-HCH), three dichlorodiphenyltrichloroethane (DDT) homologues (p,p′-DDT, p,p′-DDD, p,p′-DDE), and four cyclodienes (Aldrin, Dieldrin, Endrin and Heptachlor), indicated that concentrations of OCPs, HCHs and DDTs ranged from 0.04 to 9.95, 0 to 7.40 and 0 to 2.44 ng/g, respectively. The most dominant pollutants were the HCHs, high proportions of γ-HCH isomer indicating the recent input of lindane. The ratios of α-HCH/γ-HCH of four lakes are all lower than that in technical HCH mixtures indicated that there was input of lindane in the past several years, or that significant α-HCH evaporation into the atmosphere occurred. The ratios of (p,p′-DDE + p,p′-DDD)/p,p′-DDT in four sediments are all <1, and the mean ratios of (DDE + DDD)/∑DDT are all <0.5, suggesting recent DDT compounds input. The risk assessment was based on ERL and ERM values obtained by the approach used for assessment of ocean risk. The results suggest that OCPs in sediments of the Lake Lianhuan system poses a potential hazard to human health and environment. [ABSTRACT FROM AUTHOR]

Levels of organochlorine pesticides (OCPs) were analyzed in mollusk samples collected from markets in Dalian, China. Among 14 OCPs screened, chlordane (Chls), dichlorodiphenyltrichloroethane (DDT) and 1,2,3,4,5,6-hexachlorocyclohexane (HCH) were dominant compounds with the medians of 30.2, 5.31 and 2.03 ng/g wet weight (ww), respectively. Source analysis showed that, much higher concentrations of Chls in mollusk samples were the result of usage of the chemical in the city, HCH in samples were mainly due to historical technical HCH usage, and a small amount of fresh use of DDT might exist, causing high portion of p, p′-DDT in samples. Cumulative distribution functions for the concentrations of the selected OCPs were compared to several threshold criteria, indicating that concentrations in most mollusk samples were lower than the safe lines. The concentration data of selected OCPs were used for risk assessment, and human exposure levels were compared to noncancer and cancer benchmarks. [ABSTRACT FROM AUTHOR]

Abstract: This review summarizes and analyzes available data in the literature (mostly after 2000) on the occurrence of dichlorodiphenyltrichloroethane (DDT) and its main metabolites, dichlorodiphenyldichloroethane (DDD) and chlorodiphenyldichloroethylene (DDE), in the environment of the Pearl River Delta (PRD), South China. Generally, the concentration levels of the sum of DDT, DDD, and DDE, designated as DDTs thereafter, have not significantly declined since 1983. However, the composition of DDTs residues has changed with time. DDTs in soil, freshwater sediment and freshwater fish species were mainly residues from chronological use. There is evidence that new point sources, such as dicofol and anti-fouling paint, may have contributed DDTs to various environmental compartments. Risk assessment against existing criteria indicated that the levels of DDTs in water and some fish species may pose adverse effects to humans or wildlife, and those in sediment/soil may also cause negative impacts to the eco-environment of the PRD. [Copyright &y& Elsevier]

Advances in research on pollution of organic pesticides (OPs) in surface water, pollution survey and risk assessments of organochlorine pesticides (OCPs) and organophosphorus pesticides (OPPs) of surface water in Hangzhou are conducted. Total concentrations of dichloro-diphenyl-trichloroethane (DDT) and hexachloride-benzene (HCH) in surface water were observed to be 0–0.270 μg/L and 0–0.00625 μg/L respectively. DDE, as a metabolite of DDT and many species of OPPS were determined in some samples of surface water. Parathion, the main pollutant among OPPs in surface water of Hangzhou, was observed to be 0–0.445 μg/L. Based on these experimental results, health risk assessments on the organic pollution are developed. It is observed that the total risk “ R T” at present time of surface water in Hangzhou is mainly contributed by organophosphorus pesticides, especially Parathion; HCH and DDT are not the main contaminants; on the contrary, organophosphorous pesticides, especially Parathion, must be of concern at the present time. [ABSTRACT FROM AUTHOR]

The concentrations of semivolatile organic compounds, organochlorine pesticides and heavy metals in sediments from Jiangsu reach of Huaihe River, China, were presented. The organic compounds were extracted by acetone: n-hexane using a Soxhlet apparatus and concentrations were performed using HP6890 gas chromatography coupled by FID and ECD detector. The total contents of 8 heavy metals by inductively coupled plasma atomic emission spectrometry or cold-vapor/atomic absorption spectrometry were developed. 30 semivolatile organic compounds were detected, including substituted benzenes, phenols, phthalates and polycyclic aromatic hydrocarbons, from 0.01 to 3.01 mg/kg. 16 organochlorine pesticides were almost detected and from 0.010 to 2.339 μg/kg. Concentrations of major metals were 50 mg/kg or less, mean level of mercury was only 0.055 mg/kg. Compared to sediment quality guidelines (SQGs), concentrations of some semivolatile organic compounds were high enough to cause possible toxic effects to living resources. The organochlorine pesticides presented relatively low, lower than threshold effect concentrations (TECs), harmful effects on sediment-dwelling organisms were not expected. Chromium posed probable toxic effects to the living resources, other heavy metals had no threat temporarily according to SQGs. [ABSTRACT FROM AUTHOR]