Health risk of heavy metals in food crops grown on reclaimed tidal flat soil in the Pearl River Estuary, China.

The health risks of heavy metals to local residents via consumption of food crops cultivated in the reclaimed soils of the Pearl River Estuary (PRE) were investigated. Soils in the river estuary were found to be significantly contaminated with heavy metals, with mean concentrations of Cd, 0.858; Pb, 48.7; Cr, 112.4; Cu, 57.3; Zn, 210.8; and Ni, 40.0 mg kg(-1). Rice and root vegetables were also polluted severely. The percentages of rice samples that exceeded the maximum allowable levels were 94.3, 91.4, 88.6, and 17.1% for Pb, Cr, Cd, and Cu, respectively. The accumulation factor (AF) of Cd was the highest compared with the other five metals. The total values of the health risk index (HRI) of Cd and Cu from all the crops were 3.683 and 1.665, respectively. They exceeded considerably the allowable level 1.0. The HRI values of all the metals were mostly from rice consumption. These results suggest that more attention should be directed to the potential health risks of heavy metals to residents living in the tidal flat reclaimed areas.