The correlation study between fatty acids and organochlorine pesticides or δN values in fish tissues from Dongting Lake, China.

Organochlorine pesticides (OCPs) are ubiquitous environmental contaminants, while their correlations with δN values and fatty acids (FAs) in fish tissues remain largely unexplored. In the present study, six species of fish for daily consumption were collected from Dongting Lake, and they were dissected to tissue samples to analyze the δN values, FAs and OCPs. The results showed that the δN values of fish were ranked in the same order in different fish tissues. The polyunsaturated fatty acids (PUFAs) had a different distribution pattern in fish tissues, while the saturated fatty acid (SFAs) and monounsaturated fatty acids (MUFAs) were not. The composition of HCHs in fish tissues exhibited a tissue-specific and species-specific manner, while such pattern was not detected for DDTs. The correlation analysis indicated that the ratio of DHA/EPA was increased with the increase of δN value in the muscle, liver, gill, skin and intestine, indicating the substance flow in freshwater ecosystem. In addition, there were significant positive correlations between the concentrations of some PUFAs and OCPs in the muscle, suggesting that people should pay attention to co-intake of OCPs when they supplemented the PUFAs needed by the human body through fish.