Pollution status and health risk assessment of heavy metals in grains in Wuxi city

Abstract

ObjectiveTo investigate the pollution status of heavy metal contamination in commercially available grains in Wuxi， and to access the potential risk to humans.MethodsThe grains such as rice， flour and coarse cereals sold in Wuxi were collected， and the contents of Pb、Cd、Hg、As were detected according to the national standard method. The single factor pollution index and Nemero multi-pollution index were used to evaluate the pollution status of heavy metals in grains， and the environmental health risk assessment model recommended by the U.S. Environmental Protection Agency （US EPA） was used to evaluate the health risk caused by heavy metals through diet.ResultsThe single factor Pollution Indexs of rice， flour and coarse cereals were all less than 0.6， which is within the safe range. The carcinogenic risk value of grains is 1.71×10-4， which is within the acceptable risk level recommended by US EPA， and rice is the major exposure media. The non carcinogenic hazard quotient （HQ） of all four metals were all less than 1，which were decreased in the order of As>Cd>Hg>Pb. All the non carcinogenic hazard index （HI） was less than 1 too， which were decreased in the order of rice> flour>coarse cereals.ConclusionThe heavy metal contamination of grains in Wuxi is within the acceptable range， and the health risk assessment showed that carcinogenic risk value of grains was within the acceptable risk level recommended by US EPA. The main carcinogenic and noncarcinogenic risk all come from rice， and the attribution factor is arsenic.

Keywords

• heavy metals
• grains
• contamination
• health risk assessment