Distribution Characteristics And Risk Assessment Of Synthetic Pyrethroids In Surface Water Of East China Sea

Pyrethroid insecticides were developed in the 1970 s and are one of the most commonly used pesticides in China.Method for the study found that strain pesticides and diseases such as brain cancer,leukemia,adolescent hearing loss in children there is a positive correlation relationship,which has been confirmed in China's water,sediments and air and people's urine,in breast milk for both strain of pesticides residues,this has caught the attention of the academia and the public.The residues of pyrethroid insecticides in China have been reported,but there is a lack of research on the distribution and risk of this insecticide in the surface water of the ocean.In this study,we analyzed the residues,composition and spatial distribution of pyrethroids in the surface water of the East China Sea,and investigated the effects of nearshore input and ocean current transport on the distribution of pyrethroids in the surface water.Various methods were used to analyze the source of pyrethroid pesticides,and the health risk and environmental and ecological risk assessment of pyrethroid pesticides in surface water were conducted,and the main conclusions are as follows:(1)A detailed study of the residues of pyrethroid insecticides in 40 water samples tested for the surface water of the East China Sea showed that the concentrations of 9pyrethroid insecticides ranged from 0.0046-8.6591 ng/L,of which cypermethrin and aminothrin accounted for 80.51% of the total and 7 other categories accounted for19.49%,which was lower than the monitoring value of cyfluthrin in the Jiu Long River estuary area of Fujian The monitoring value of 14.80?29.72 ng/L is also lower than that of 770 ng/L in the Mekong River basin of Vietnam,indicating that the inland runoff has a higher content of pyrethroid pesticides than marine pyrethroids,and is in the same order of magnitude as Norway's nearshore <10 ng/L.(2)The Yangtze River,Qiantang River,and Oujiang River are the main runoffs of pyrethroid pesticide input to the East China Sea,and the offshore input from coastal areas is the main source of pyrethroid pesticide pollution in the East China Sea.In addition,the movement of ocean currents also plays an important role in the transportation of pyrethroid pesticides,and about 6.6625 tons of pyrethroid pesticides enter the Sea of Japan from the East China Sea via Tsushima Strait every month.(3)The correlation between each pyrethroid insecticide with detection rate >75%was studied and analyzed using SPSS.The results showed that there was a significant correlation between cypermethrin,fluvalinate and cyfluthrin(p<0.05).A comparative analysis of nine pyrethroid insecticides was conducted using the PCA-MLR model and pheatmap cluster analysis,and was found to be related to their distribution at the same loci presenting the highest concentrations.The pyrethroid insecticides in the surface water of the East China Sea are mainly from human-centered activities such as acaricides,aquaculture,agricultural use and household use.(4)Ecological risk entropy(RQ)and hazard quotient(HQ)were calculated to assess the ecological and health risks posed by pyrethroid pesticides to surface waters and coastal areas in the East China Sea based on reference values provided by the U.S.Environmental Protection Agency(US EPA).Pyrethroid insecticides exhibited moderate ecological risk,with permethrin playing a major contribution,which was lower than the ecological risk level of Chaohu and Taihu lakes.In terms of health risk assessment,the contamination levels of pyrethroid pesticides in the East China Sea are safe for humans in the surrounding area under moderate and high exposure and are not carcinogenic.Overall,the risk in the East China Sea and its surrounding areas is at a low level.However,the entry of pyrethroid pesticides such as permethrin into the East China Sea should be controlled in order to reduce the possible ecological hazards.More studies on the transport process of pyrethroid pesticides and their combined toxicity are needed to facilitate better evaluation of the environmental risks and pelagic feedbacks of pyrethroid pesticides in and around the sea area.