Pollution Sources Of Lead In Jintan Inarticulate Water Dropwort And The Control Technologies

Lead (Pb) is the most important pollutant in the production of Jintan inarticulate water dropwort, and has been threatening the quality of water dropwort products and the health of consumers. In this research, the pollution sources of Pb in Jintan inarticulate water dropwort production and the preventing technologies were studied. The results showed that Pb concentrations of the soils and fertilizers in the production area were 18.3-33.6 mg/kg and 0.06-1.13 mg/kg respectively, and the values were all below the maximum allowable concentration (MAC) of Pb according the Chinese Standards. Pb concentrations of irrigation water ranged from 0 to 0.08 mg/L, and 19.05% of water samples exceeded the MAC. Furthermore, Pb concentrations of water dropwort was closely related to Pb levels in irrigation water (r = 0.9631, P < 0.01). Therefore, Pb pollution of irrigation water is the main source of Pb contamination in water dropwort products. Under the treatment of 0.01, 0.02 and 0.03 mg/L Pb in irrigation water, Pb concentrations in the water dropwort were below the MAC for water dropwort (0.1 mg/kg, GB 2762-2012). But under the treatment of 0.04 and 0.05 mg/L Pb in irrigation water, Pb concentration of water dropwort was 86% and 159% higher than the MAC, respectively. So the present Chinese standard on water quality (Pb <= 0.05, NY 5010-2002) may be not suitable for safe production of Jintan inarticulate water dropwort. Silicon, calcium superphosphate and unslaked lime fertilizers could restrain Pb uptake by water dropwort, and reduced Pb pollution in Jintan inarticulate water dropwort effectively.