Fuzzy health risk assessment and integrated management of toxic elements exposure through soil-vegetables-farmer pathway near urban industrial complexes

摘要

Urban industrial areas were being built globally, which decreased key geographical separation between agriculture and industrial areas, especially in developing countries. Now, limited studies concerned coordinated the vegetables and soil management for toxic elements (TEs) in this mixed land system. To fill this gap, an integrated environmental multi-media risk management method was explored based on laboratory analysis, health risk assessment, uncertainty control, and source apportionment. The Chinese Beihu area of Wuhan City was selected as a typical case and the measurements of Zn, Cr, Cu, Pb, As, and Cd in soil revealed that TEs pollution was slight and concentrations met the Chinese standards. Meanwhile, some vegetables exceeded corresponding standard limits. To further quantify negative health effects posed by the studied TEs both in soils and vegetables, an established fuzzy health risk assessment for farmers was employed and the results indicated that the soil exposure of As and the vegetable consumption needed the priority control. The carcinogenic risk (CR) of As in soil was [4.60E-6, 1.45E-5] and the cumulative CR (sum of CR_(As), CR_(Pb) and CR_(Cd)) in leafy vegetables was [1.08E-4,1.38E-4], which was higher than that of the other vegetables. Preventing soil oral exposure and reducing self-grown vegetable consumption (30%-50%) were proven as effective risk interventions via uncertainty control methods. Spatially, the risk grades under maximum membership principle decreased from south to north in the Beihu area, and the south area was identified as the priority control area. Source apportionment identified four source patterns (Zn-Cr-Cu, Pb, As, and Cd) for soil, and the probable bioaccumulation mechanisms for leafy vegetables by multivariate statistical analyses. Finally, the integrated management strategies were formulated from perspectives of the risk sources, exposure pathways and the scenario.