江西省某县大米镉污染情况追踪调查

目的了解镉污染区19年后当地产大米镉污染情况。方法在全县主要水稻种植乡镇采集当地2006年晚米。使用电感耦合等离子质谱(ICP-MS)分析测定米镉含量。结果2006年产大米镉含量均值为:污染区0.59mg/kg,对照区0.05mg/kg。与1987年测定结果相比大米镉含量增加近30%。全县2006年产受污染大米镉含量均值为0.26mg/kg,大于国家卫生标准值,明显高于对照米样镉含量均值(0.06mg/kg)。其中有64%的大米样品大于国家卫生标准值,23.17%的大米样品≥0.4mg/kg、11%的大米样品为≥1.0mg/kg的"镉米"。部分乡村"镉米"检出比例更高,达到33.3%以上。结论当地1987年调查点环境镉污染近19年来仍在持续,米镉含量均值较19年前增加约30%,达到0.59mg/kg。全县污染区2006年产米镉均值超过国家卫生标准值,环境镉污染仍在持续加重,迫切需要采取环境治理与人群暴露阻断措施。

A following up survey on cadmium level in rice in contaminated area,Jiangxi Province

Objective To observe rice cadmium level in a contaminated area where has being continuously polluted for 19 years since last investigation. Methods Samples of late rice (polished) grown in 2006 were collected from farmer household in contaminated and control area and its cadmium concentration were detected with IPC-MS. Results Samples of polished rice from the polluted and control areas were detected. The average cadmium concentration from last investigation area 19 years before was 0.59mg/kg (0.05mg/kg for rice from control area), it upraises about 30% corresponding to average of rice from the same areas detected before 19 years. The average cadmium level of rice from whole contaminated areas (including last investigation and expanding areas) was 0.26mg/kg and it is greater than that in control areas (0.06mg/kg) and the limited value of national hygiene standard (<0.20mg/kg). There was about 64%, 23.17 % and 11% of samples have higher level than 0.20mg/kg (the limited value of national hygiene standard), 0.4mg/kg (the limited value of Codex General Standard) and 1.0mg/kg (cadmium-rice) respectively. There was a higher percentage (36.8 %) of Cadmium-rice (greater than 1.0mg/kg) in some heavy contamination villages. Conclusion Environmental cadmium pollution has being existing for 19 years since last investigation. Average cadmium concentration of rice from whole country polluted areas was higher than that of national hygiene standard. Percentage of "cadmium-rice" might be higher in some villages.