Spatial distribution, source identification, and risk assessment of organochlorines in wild tilapia from Guangxi, South China

Yang Ding,Zhiqiang Wu,Yaru Kang,Kefu Yu,Ruijie Zhang,Xiaobo Zheng,Yinghui Wang,Liangliang Huang,Lichao Zhao

doi:10.1038/s41598-020-72160-x

Yang Ding, Zhiqiang Wu + Show 7 more

Open Access

https://doi.org/10.1038/s41598-020-72160-x

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Abstract

Seventy-five wild tilapia samples from six rivers (ten sites) in Guangxi province were collected and analyzed for 53 organochlorine compounds. DDTs, endosulfan, and PCBs were the most dominant compounds found in this study. Tiandong County (TD) and Guigang City (GG) sites were found to be heavily contaminated with high levels of endosulfan (385–925 ng/g lw) and/or DDTs (20.1–422 ng/g lw). The diagnostic ratios indicated that the residues of DDTs and endosulfan in wild tilapia are associated with historical applications as well as the recent introduction of technical DDTs and endosulfan at some sampling sites. The correlation between total length, body mass, and organochlorines (OCs) was higher than the correlation between age and lipid content. There was no significant correlation between organochlorine pesticides (OCPs) and lipid content. Therefore, for organisms, the feeding intensity (related to length and mass) of fish could better reflect degree of pollution than exposure time (age) of fish. The hazardous ratios for the 50th and 95th percentile data of OCPs and PCBs in fish were both below 1, suggesting that daily exposure to OCPs and PCBs yields a lifetime cancer risk lower than 1 in 10,000.

Highlights

Seventy-five wild tilapia samples from six rivers in Guangxi province were collected and analyzed for 53 organochlorine compounds
Of OCs in wild tilapia collected from the main rivers of Guangxi, South China; (2) obtain detailed information on the spatial distribution and composition pattern to identify possible sources of OCs in the wild tilapia; (3) explore the relationship between OCs congeners and biological parameters, i.e. total length, body mass, age and lipid content; and (4) evaluate the potential health risks of OCs associated with wild fish consumption by residents
This study showed that the main rivers in the southern Guangxi have low levels of OCs pollution, and the fish muscle contamination might be related to the low levels of pollution in the water and sediment

Summary

Introduction

Seventy-five wild tilapia samples from six rivers (ten sites) in Guangxi province were collected and analyzed for 53 organochlorine compounds. The correlation between total length, body mass, and organochlorines (OCs) was higher than the correlation between age and lipid content. The consumption of polluted fish is one of the main sources among many sources of organic pollutants in human body. Of OCs in wild tilapia collected from the main rivers of Guangxi, South China; (2) obtain detailed information on the spatial distribution and composition pattern to identify possible sources of OCs in the wild tilapia; (3) explore the relationship between OCs congeners and biological parameters, i.e. total length, body mass, age and lipid content; and (4) evaluate the potential health risks of OCs associated with wild fish consumption by residents

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