苏州市地产大米重金属污染状况及人群膳食暴露风险评估

目的 研究苏州地产大米中铅、镉、总汞、总砷4种重金属污染状况, 并评估4种重金属对苏州居民的膳食暴露风险。方法 2019年从苏州市属9个区县采集本地产大米93份, 采用国标方法检测其中铅、镉、总汞、总砷4种重金属的含量, 依据GB2762-2017《食品安全国家标准 食品中污染物限量》对样品中重金属超标情况进行判定; 采用单因子污染指数法、内梅罗综合污染指数法评价大米中4种重金属的污染程度; 采用简单分布模型(确定性评估)的方法评价大米中重金属对苏州居民造成的膳食暴露风险。结果 全部大米样品中铅、镉、总汞、总砷4种重金属均未超过国家限量标准, 铅、镉、总汞和总砷污染水平均值分别为0.0208、0.0419、0.0027和0.0701 mg/kg, 各区县大米中重金属含量水平之间无统计学差别。大米中4种重金属单项污染指数均小于0.7, 污染程度处于优良水平; 综合污染指数小于0.7, 污染程度处于安全水平。苏州地产大米中铅的污染对苏州本地居民95%的儿童及所有成人均不会产生健康危害, 但可能对5%的儿童(高食物消费暴露者)产生潜在健康影响; 镉、总汞、总砷污染对成人和儿童均不会产生健康危害。结论 苏州市地产大米中重金属污染水平较低; 大米中铅的污染可能对高食物消费暴露儿童存在潜在健康危害。

Heavy metal pollution status of local rice and human dietary exposure risk assessment in Suzhou city

Objective To study the pollution status of four heavy metals in Suzhou rice, including lead, cadmium, total mercury and total arsenic, and to evaluate the dietary intake risk of the four heavy metals to Suzhou residents. Methods Totally 93 local rice samples were collected from nine counties of Suzhou city in 2019, and the contents of four heavy metals, including lead, cadmium, total mercury and total arsenic, were detected using national standard methods. According to GB2762-2017 National food safety standard-Limits of contaminants in food, heavy metal exceeding standard in the sample were judged. The pollution degree of 4 heavy metals in rice was evaluated using the single factor pollution index and Nemero comprehensive pollution index, and the dietary exposure risk of heavy metals in rice to Suzhou residents was evaluated by simple distribution model (deterministic assessment) method. Results All the 4 heavy metals of lead, cadmium, total mercury and total arsenic in the rice samples did not exceed the national limit standards, and the average pollution levels of lead, cadmium, total mercury and total arsenic were 0.0208, 0.0419, 0.0027 and 0.0701 mg/kg, respectively. There was no statistical difference between the heavy metal content levels in rice from each county. The single pollution index and comprehensive pollution index of rice were less than 0.7, which were below the limits of safety. Lead contamination in Suzhou rice does not pose a health hazard to 95% of children and all adults of Suzhou residents, but may have a potential health impact on 5% of children (those exposed to high food consumption). Cadmium, total mercury and total arsenic pollution would not cause health hazards to adults and children. Conclusion The pollution of heavy metals in rice grown in Suzhou is generally low. Lead contamination of rice may cause a potential health hazard to a small number of children exposed to high food consumption.