Resumen
China is an agriculturally-producing country and the safety of its vegetables will have an extensive attention at home and abroad. Recently, contamination of soils and vegetables caused by mining activities is of great social concern because of the potential risk to human health, especially to the residents whom live near metal or metalloid mines. In this study, 18 topsoil and 141 vegetable samples were collected from the contaminated areas in Daye City Hubei Province, China and the concentrations of copper (Cu), zinc (Zn), arsenic (As), cadmium (Cd) and lead (Pb) were analyzed. A self-designed questionnaire was assigned to obtain the exposure scenario and the USEPA health risk assessment model was adopted to assess two type of risks (non-carcinogenic risks and carcinogenic risks) of vegetables to humans. The results showed that the average contents of metal(loid)s in soils exceeded the background value of Daye City. The average contents of metal(loid)s, especially As, Cd, Pb, in three kinds of vegetables were significantly higher than the permissible values based on Chinese national standard. Leafy vegetables had relatively higher concentrations and the transfer factors of As (0.015), Cd (0.080) and Pb (0.003) were comparable to leguminous and fruit vegetables. Leguminous vegetables had relatively higher concentrations and transfer factors of Cu (0.032) and Zn (0.094) than leafy and fruit vegetables. The transfer factors from soil to plants follows a decreasing order as Cd (0.068), Zn (0.047) > Cu (0.023) > As (0.006), Pb (0.002). Furthermore, health risk assessment revealed the following results: the non-carcinogenic risk decreased in the order of children, adult, adolescent, while the carcinogenic risk followed a decreasing order of adult, adolescent, children; the calculated carcinogenic and non-carcinogenic risk of the metal(loid)s by vegetable consumption decreased in the order of leafy vegetables > fruit vegetables > leguminous vegetables. The relatively lower transfer factors and lower risks may suggest that leguminous and fruit vegetables are more suitable for planting in Daye City. Based on the contributions of five kinds of metal(loid)s from three types of vegetables, Cd and As are found to be the dominant sources of health risk.