江苏省稻米镉含量调查及其膳食暴露评估

为评价江苏省稻米重金属镉污染现状,于2013年在全省13市调研抽检了1101份稻谷,采用石墨炉原子吸收光谱法测定稻米中的镉含量。检测结果显示,全省稻米镉的检出率为97.6%,平均含量为0.036 4 mg·kg~(-1),检出范围是0.000 3~0.431 0 mg·kg~(-1),仅有0.27%的样本超出0.2 mg·kg~(-1)的限量。整合我国居民20个性别年龄组人群的稻米消费和体重信息,采用非参数概率模型对稻米镉的膳食暴露量进行评估,并与JECFA推荐的镉的暂定每月耐受摄入量(PTMI)25μg·kg~(-1)体重相比,评估结果表明,我国居民食用江苏地区稻米产生的平均镉暴露风险尚可接受,但在P95的风险水平下,14岁以下人群的摄入量相对较高,占PTMI的86.3%~130.7%,其中11岁以下人群中有6.8%~9.0%的个体摄入量超过PTMI,潜在风险较大。建议对稻米中的重金属镉进行持续监测。

Survey and dietary exposure assessment of cadmium in milled rice in Jiangsu Province

A survey of cadmium levels in milled rice in Jiangsu Province was carried out in 2013. A total of 1101 milled rice samples were collected from 13 cities. Cadmium was measured by graphite furnace atomic absorption spectroscopy. Results showed that 97.6% of the samples contained detectable concentrations of cadmium, which ranged from 0.000 3 to 0.431 0 mg·kg-1, with the mean value of 0.036 4 mg·kg-1, but only 0.27%of the samples had cadmium concentrations exceeding the maximum level(ML), 0.2 mg·kg-1. Based on recent rice consumption and body weight, an estimated monthly human intake of cadmium was calculated for 20 age-sex categories of Chinese popula-tion using a non-parameter probabilistic model. The provisional tolerable monthly intake(PTMI)of cadmium, as recommended by the Joint FAO/WHO Expert Committee on Food Additives(JECFA)was 25 μg·kg-1 bw. The estimated exposure values for populations of interest were compared to the PTMI. This study confirmed a low average health risk of cadmium via the milled rice in Jiangsu Province. For the pop-ulation below 14 years old, however, exposure to cadmium represented 86.3%~130.7%of the PTMI at P95 risk level. For population below 11 years old, 6.8%~9.0%individuals had cadmium exposure exceeding the PTMI. The present study suggests that it is necessary to estab-lish a program to monitor cadmium dynamics in milled rice continuously.