Assessment of Heavy Metal and Herbicide Levels in Soil and Plant Products from Agricultural Area of Tieling District, Liaoning Province, China

This study was aimed to assess the levels of selected heavy metals and herbicides in soils under different land usage and plant products from an agricultural area of Tieling district, Liaoning Province, China. Cd, Pb, atrazine, acetochlor and butachlor were analyzed from maize, paddy and vegetable field. Cd concentrations in 40% of vegetable soils and 6.67% of rice soils were higher than "Environmental quality standard for soils" (GB15618-1995), respectively. Cd concentrations in 20% of vegetable samples were higher than "Pollution-Free vegetables standard" (GB18406.1-2001) and Pb concentrations of all vegetable samples were lower than the standard. The Cd concentrations in maize and rice samples did not exceed "Maximum levels of contaminants in foods"(GB2762-2005), Pb concentrations in 26.7% of maize samples and 13.3% of rice samples were higher than levels. The vegetables affected by Cd pollution were more serious than maize and rice, but the latter affected by Pb pollution were more serious than the former. Residues of three herbicides were detected in soils, with levels lower than the relevant limit. The residue levels of atrazine, acetochlor and butachlor in soils were vegetable soil>;maize soil>;paddy soil, maize soil>;vegetable soil>;paddy soil, paddy soil >; vegetable soil >; maize soil, separately. Atrazine was detected in all vegetable samples due to high application rates of previous periods in vegetable. Acetochlor and butachlor were detected in rice samples, with levels lower than the relevant limit. Detection rate (83.7%) of acetochlor was much higher than that (10.0%) of butachlor. Detection values of butachlor in rice were 1.92, 2.60 and 3.99μg·kg^-1, respectively. The content of atrazine, acetochlor and butachlor in rice and vegetable should be monitored continuously, as they are well known to be persistent and accumulative chemicals.