Okada I A, Sakuma A M, Maio F D, Dovidauskas S, Zenebon O
Rev Saude Publica. 1997 Apr;31(2):140-3. doi: 10.1590/s0034-89101997000200006.
A factory producing lead ingots, located in Caçapava, caused lead and cadmium contamination of the environment, in the Paraiba Valley region of Southeastern, Brazil, through the discharge of industrial waste and the recycling of batteries. The factory, set in a rural, dairy cattle breeding area, worried sanitary authorities who envisaged the possibility of these metals' having entered the food chain. For the purpose of assessing the levels of contamination of the milk produced in the region, due to the cattle's possible consumption of contaminated grass and water, the amounts of cadmium and lead present in the milk were verified.
Major producers, covering an area of up to 20 km from the contaminated source, authorized collection of 218 samples of both pasteurized and non-pasteurized milk, which were analysed. Lead and cadmium levels were determined by flame atomic absorption spectrophotometry, the lead being pre-concentrated by complexation with APDC (ammonium 1-pyrrolidinecarbodithioate) and further extraction with isobutyl methylketone.
Of the total number of samples, 43 presented lead levels over the maximum limit of 0.05 mg/kg established by Brazilian legislation. The median value found for lead was 0.04 mg/L. The variance analysis, with 95% confidence level, found no significant difference among the types of milk studied with regard to lead levels. As for cadmium, all samples showed levels below the 0.02 mg/L quantification limit of the method. In spite of the environmental contamination, the levels of cadmium found in the milk were below the 1.0 mg/kg limit established by Brazilian legislation.
位于巴西东南部帕拉伊巴河谷地区卡沙帕瓦的一家铅锭生产厂，通过排放工业废料和回收电池，造成了环境中的铅和镉污染。这家工厂位于一个乡村奶牛养殖区，这让卫生当局感到担忧，他们设想了这些金属进入食物链的可能性。为了评估该地区生产的牛奶的污染程度，由于奶牛可能食用了受污染的草和水，对牛奶中镉和铅的含量进行了检测。
主要生产商位于距离污染源20公里以内的区域，他们授权采集了218份巴氏杀菌奶和未杀菌奶样本进行分析。铅和镉的含量通过火焰原子吸收分光光度法测定，铅通过与吡咯烷二硫代氨基甲酸铵（APDC）络合进行预浓缩，然后用异丁基甲基酮进一步萃取。
在所有样本中，有43份样本的铅含量超过了巴西法律规定的0.05毫克/千克的上限。铅的中位数为0.04毫克/升。在95%置信水平下的方差分析发现，在所研究的不同类型牛奶中，铅含量没有显著差异。至于镉，所有样本的含量均低于该方法的0.02毫克/升定量限。尽管存在环境污染，但牛奶中发现的镉含量低于巴西法律规定的1.0毫克/千克的限值。
