Residues of organochlorine pesticides (OCPs) in aquatic environment and risk assessment along Shaying River, China

Abstract

Organochlorine pesticides (OCPs) are pesticides with global scale ubiquity, persistence and bioaccumulation, which leave long-term residuals in the water body. OCPs' high toxicity poses significant threats to human health and aquatic biodiversity, making assessment of OCPs' impact on aquatic ecology and human health urgently necessary. In this research, the presence of 16 OCPs in surface water and groundwater along Shaying River, China, as well as OCPs concentration correlations, was investigated at 24 selected sampling sites. At the same time, the ecological risk and human carcinogenic risk were also analyzed by risk quotient method and USEPA's Risk Assessment Guidance, respectively. Results showed that the total concentration of OCPs ranged from 21.0 to 61.4 ng L in groundwater, and 12.3-77.5 ng L in surface water. Hexachlorocyclohexane (HCHs) and heptachlor were the prominent contaminants in groundwater, which indicated their use in the recent past and confirmed their persistence. The α-HCH/γ-HCH ratios in groundwater confirmed that γ-HCH (lindane) was used as main substitute of technical HCH in the study area. The correlation analysis illustrated that δ-HCH and γ-HCH played a dominant role in HCHs residue. Heptachlor and α-HCH, as well as endosulfan and heptachlor epoxide, had a strongly significant positive correlation, suggesting an associated usage of the two pair OCPs. An extremely high ecological risk for aquatic organism was observed for γ-HCH, heptachlor and dieldrin, while the carcinogenic risks posed by the selected OCPs in surface water and groundwater were all acceptable.

Levels of 15 Organochlorine Pesticide in Freshwater during Several Seasons along the Nile River, Egypt

“…Also, Modibbo et al (2019) studied the pesticides residue in the water samples collected at the four sampling points in the lake of Njuwa, Adamawa state and detected α-BHC, Endrin, Endosulfan with higher concentration in the surface water which were Endosulfan (0.92 μg/L), Endrin (0.82 μg/L), alpha-BHC (0.57 μg/L). On the other hand, Bai et al (2018) investigated the residues of OCPs along Shaying River in groundwater and surface water, China, at 24 selected sampling sites. The concentration of OCPs were 21.0 -61.4 ng L -1 in groundwater, and 12.3-77.5 ng L -1 in surface water.…”

“…As of their high perseverance, they can be accrued in the human body by regular consumption of plant crops and drinking water, Dipo et al (1999). Also, High toxicity of OCPS, possess important fears to human health and aquatic organisms, assess the OCPs impact on aquatic ecosystem and human health instantly essential, Bai et al (2018). Kafr El-Zayat district is an agricultural and industrial area, it has a major pesticide factory in Egypt, in addition, there is the company of salt and soda and America, Oil and Soap company also financial company to production superphosphate.…”

Ecological and health risk assessment of organochlorine pesticides in an urbanized river network of Shanghai, China

“…where HC 5 is the OCP concentration at which 5% of species are exposed to chronic hazards, mg/L; and AF an assessment factor, which considers the uncertainty between laboratory toxicology tests and the real environment. In this study, AF = 100 [4]. HC 5 was calculated using species sensitivity distribution (SSD) method [21].…”

“…According to different evaluation criteria and management purposes, the classification of ecological risks was different [4,6,22,23]. Overall, an RQ value greater than 1 indicates that the concentrations of OCPs in the environment are higher than the predicted no-effect concentrations.…”

“…However, owing to the large amount of OCPs used for such a long time in the past, their residues in the environment are still hot spots of contamination. During the past two decades, high levels of OCPs in the water, sediments, and aquatic biota of many important rivers in China, such as the Shayin River [4], the Yellow River [5], and the Pearl River [6], could be still detected. South China (the Pearl River Delta) has been considered as one of the areas in China with high environmental concentrations of pesticides [6].…”