Occurrence, accumulation, and health risks of heavy metals in Chinese market baskets

Residual levels and accumulation characteristics of six hazardous heavy metal elements (As, Cd, Hg, Tl, Pb, and U) and seven essential heavy metal elements (Cr, Mn, Fe, Ni, Cu, Zn, and Se) were investigated in 17 kinds of frequently consumed foodstuffs collected from 33 cities distributed in five regions of China. The concentrations of the detected metals were lower than the maximum limits promulgated by the Chinese government except Pb and inorganic As (iAs). Foods of aquatic origin and terrestrial plant origin exhibited high potentials to accumulate heavy metals, especially algae and shellfish. The calculated hazard index (HI) of heavy metal exposure via consumption of foodstuffs were 2.93-5.01 for adults in the five surveyed region, implying the co-exposure of heavy metals via food consumption would lead to potential non-carcinogenic risks. iAs was the predominant contributor to HI values with the average contribution of 40.5% in all five regions. Consumption of terrestrial plant origin foods contributed 76.9% of HI values induced by heavy metal exposure. The calculated target cancer risks of iAs in the five regions were 5 x 10(-4)-1 x 10(-3), all exceeding the acceptable level of 10(-4), indicating it is necessary and urgent to reduce the contamination of iAs in foodstuffs on the Chinese markets.

Automated summary

This study investigated residual levels and accumulation characteristics of hazardous and essential heavy metal elements in commonly consumed foodstuffs from different regions in China. The results showed that aquatic and terrestrial plant foods had higher potentials to accumulate heavy metals. Co-exposure to heavy metals through food consumption posed potential non-carcinogenic risks. In particular, inorganic As (iAs) was the main contributor to the risk, and terrestrial plant foods contributed significantly to the overall hazard index.