Analysis of Heavy Metals in Foodstuffs and an Assessment of the Health Risks to the General Public via Consumption in Beijing, China

Consumption of foodstuffs is the most likely route for human exposure to heavy metals. This study was designed to investigate the toxic metals (cadmium (Cd), lead (Pb), chromium (Cr), arsenic (As), and mercury (Hg)) concentrations in different foodstuffs (cereals, vegetables, fruits, fish, and meat) and then estimate the potential health risks of toxic metals via consumption to the local residents in Beijing, China. Most of the selected toxic metal levels in the foodstuffs were lower than the maximum allowable concentrations of Pb, Cr, Cd, As, and Hg for Chinese foodstuffs recommended in the China National Food Safety Standard. The health risks associated with the toxic metals Pb, Cr, Cd, As, and Hg were assessed based on the target hazard quotients (THQs) proposed by the United States Environmental Protection Agency (US EPA). The THQ values of the foodstuffs varied and were 0.03-0.29 for Cr, 0.02-0.23 for Pb, 0.01-0.33 for Cd, 0.01-0.06 for As, and 0.00-0.04 for Hg, not exceeding the maximum level of 1. The total THQ (TTHQ) values were 0.88 for vegetables, 0.57 for cereals, 0.46 for meat, 0.32 for fish, and 0.07 for fruits. This indicates that the risk contribution from vegetable intake (38.8%) was significant in comparison to that from other foodstuffs. The TTHQ values were 0.96 for Cr, 0.54 for Pb, 0.50 for Cd, 0.19 for As, and 0.09 for Hg, suggesting that Cr was a major risk contributor (41.7%) for the local residents of Beijing, which should attract great attention. However, the THQ/TTHQ values were all below 1, suggesting no health risks to the local population through consumption. Furthermore, dietary weekly intakes (WIs) were also calculated and the values were all lower than the proposed limit of Provisional Tolerable Weekly Intakes (PTWI) established by the the Food and Agriculture Organization of the United Nations (FAO) and the World Health Organization (WHO). This suggests no additional health risks as well as consistency with the THQ results.