Health risks of heavy metals in sewage-irrigated soils and edible seeds in Langfang of Hebei province, China

BACKGROUND: Human exposure to heavy metals is attributed to consumption of food crops grown in polluted soil environment. The objective of our study was to assess the health risks of heavy metals in edible seeds of crops grown in sewage-irrigated soils located in the Langfang of Hebei province, China. Here, heavy metal contents in soils and plants were determined using an internal standard and high-resolution inductively coupled plasma mass spectrometry. RESULTS: There was a relative buildup of heavy metals in sewage-irrigated soils in the study area; in particular, all Cr and partial Zn and Cu showed higher concentrations than the limits proposed by the World Health Organization, European Union (EU) and UK. Heavy metal concentrations in edible seeds of plants grown in sewage-irrigated soils partly exceeded the permissible limits set by the EU, UK and the State Environmental Protection Administration in China. With the exception of Cu, health risk index values of each heavy metal investigated by intake of the edible seeds were less than 1. Here, a health risk index of < 1 is considered safe for human consumption. CONCLUSION: The study indicated that there was a relative absence of health risks associated with the ingestion of sewage-irrigated edible seeds. (C) 2009 Society of Chemical Industry