无锡市谷物重金属污染状况及健康风险评估

目的 了解无锡市市售谷物重金属污染状况以及对人体的潜在健康风险。方法 采集无锡市市售大米、面粉、杂粮等谷物，根据国家标准方法对谷物中的铅、镉、总汞、总砷进行检测。运用单因子污染指数和尼梅罗综合污染指数评价谷物中重金属污染状况，采用美国国家环境保护局（US EPA）推荐的环境健康风险评价模型对重金属通过膳食途径所引起的健康风险做出评估。结果 大米、面粉、杂粮的单因子污染指数均小于0.6，在安全范围内。谷物总致癌风险值为1.71×10^-4，大米的致癌风险值最高，为3.29×10^-4。4种重金属的非致癌危险商（HQ）均小于1，由高到低依次为总砷、镉、总汞和铅，不同种类谷物的重金属非致癌危险指数（HI）均小于1，由高到低依次为大米类、面粉类、杂粮类。结论 无锡市谷物重金属污染在安全范围内，对健康风险进行评估显示，谷物中重金属对人体健康的整体风险在可接受范围内，致癌风险在EPA推荐的可接受范围内，其中大米的致癌风险最高，主要贡献为总砷；非致癌风险也在可接受范围内，其中大米的非致癌风险最高，主要贡献仍为总砷。

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

Objective To investigate the pollution status of heavy metal contamination in commercially available grains in Wuxi， and to access the potential risk to humans.Methods The 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.Results The 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.Conclusion The 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.