[Health risk assessment of soil heavy metals in residential communities built on brownfields].

ABSTRACT

Nine residential communities which were built on different brownfields in a city of Henan Province were chosen to investigate the health risks of heavy metals (As, Hg, Cd, and Pb) in surface soils. Concentrations of soil heavy metals were measured according to the methods described in the national standard. Based on the health risk models recommended by the U. S. Environmental Protection Agency (US EPA), non-carcinogenic and carcinogenic health risks of soil heavy metals were assessed. The results showed that compared with the original brownfields, the heavy metal concentrations in soils and their health risks in residential communities built on brownfields were significantly improved, and the concentrations and health risks of soil heavy metals in these communities were all higher than those in non-brownfield residential communities. The HQ and HI values of soil heavy metals in all the residential communities were lower than 1, which indicated that there was no non-carcinogenic risk in these communities. Meanwhile, the values of CR and TCR were slightly higher than the standard suggested by the US EPA, indicating that slight carcinogenic risks in the communities, but these values were lower than the lenient standard proposed by some experts. The HI value of the four metals for children was exactly seven times higher than that for adults. The contribution rate of HQ(As) to HI was about 75%, CR(AS) to TCR was about 80%, and therefore arsenic was the crucial factor for carcinogenic and non-carcinogenic risk in the residential communities of the city.