Bioaccessibility and health risk assessment of trace metals in soils of greenhouse vegetable production near the industrial areas of the Yangtze River Delta, China

As a common environmental problem in China, trace metal accumulation and contamination in soils of greenhouse vegetable production (GVP) may pose significant health risk via oral ingestion, inhalation, and dermal contact to vegetable farmers and children playing in greenhouse fields. Thus, bioaccessibility and health risk of Cr, Ni, Cu, Zn, Cd, and Pb in GVP soils collected from 13 GVP farms or bases near industrial areas of the Yangtze River Delta, China, were investigated as a case study. The results suggested that both GVP and industrial discharges contributed a lot to accumulation or contamination especially of Zn and Cd in soil, which subsequently increased their bioaccessible concentrations. In addition, soil acidification caused by GVP also increased bioaccessible Cr and Ni concentrations in soil of the Anthrosols study area. However, the health risk assessment of metals in GVP soil through inhalation and oral ingestion considering metal bioaccessibility suggested no non-carcinogenic and carcinogenic risks to both farmers and children. In contrast, there was potential carcinogenic risk within acceptable level posed by Cr in GVP soil through dermal contact to farmers and children. This indicates that both GVP and industrial activities had limited effect on health risk of trace metals in GVP soil via ingestion, inhalation, and dermal contact. However, the carcinogenic risk posed by Cr, which mainly originated from natural sources, still cannot be negligible. Overall, the results will provide valuable information for decision-makers to develop reasonable strategies and guidelines for risk management of trace metals in GVP soil.