Distribution and partitioning of pyrethroid insecticides in agricultural lands: Critical influencing factors.

Pyrethroid insecticides are widely applied due to the broad spectrum and high efficiency in pest control and detected in various environmental media, but the key factor affecting their occurrence and distribution in agricultural lands is still not clear. Here, we measured pyrethroid residues in 644 surface soil and 630 surface water samples and quantified the impacts of various factors on the distribution and partition of pyrethroids through a large-scale field study in Southeast China during 2015-2017. The pyrethroid residues were widely detected in the studied areas, and the mean concentration of seven individual pyrethroids in surface soil and water ranged from 0.10 (cyfluthrin, (CYF)) to 12.14 ng/g (bifenthrin, (BIF)) and 0.18 (CYF) to 3.36 µg/L (BIF) respectively, which were higher than other regions in China and some other countries. Using a generalized linear model coupled with dominance analysis, we found that the crop type and season were significantly associated with pyrethroid residues in surface soil and water (p < 0.05). The crop difference dominated the variances of the distribution of pyrethroid residues in the surface soil and water with a contribution of more than 55% and followed by the factor of season difference. The findings provide new insight into the distribution and partitioning of pyrethroids in agricultural lands and insecticide control on ecological safety and public health.