Residues of neonicotinoid insecticides in surface sediments in lakes and rivers across Jiangsu Province: Impact of regional characteristics and land use types.

Neonicotinoid insecticides (NNIs) had been detected in soil and surface water frequently because of extensive use worldwide, however, data regarding regional characteristics and potential influential factors of sediment were scarce. In the present study, eight NNIs were analyzed in 86 surface sediment samples from different regions (central cities, rural areas and suburbs) and land use types (construction land and crop land) in Jiangsu Province. NNIs were widespread in the sediments, with a mean value of 1.73 ± 0.89 ng g-1 dry weight (dw) (ranged from 0.41 to 3.87 ng g-1 dw). Imidaclothiz (IMIZ), dinotefuran (DIN) and nitenpyram (NIT) were the dominant compounds in the surface sediment, accounted for half of combined total. The results of regional distribution analysis show that NNIs were at higher concentrations in rural areas and crop land, while the residues of NNIs in lakes were more severe compare with rivers in Jiangsu Province. Region characteristics and land use types have an influence on residues of NNIs in surface sediment. Principal component analysis showed that residues of NNIs in surface sediment in Jiangsu Province mainly originated from protect grain crops (maize), fruit (apples, pears) and vegetables in agricultural systems. The residues of NNIs were found to be mostly concentrated in the northwest and northeast in Jiangsu Province, where were the area of intensive agriculture. To investigate the residues of NNIs, while identify the contributing factors, could provide a scientific basis for basic of region environment management and pollution control.