Waliszewski S M, Villalobos-Pietrini R, Gómez-Arroyo S, Infanzón R M
Institute of Forensic Medicine, University of Veracruz, SS Juan Pablo II s/n 94290, Boca del Rio, Ver, Mexico.
Food Addit Contam. 2003 Mar;20(3):270-5. doi: 10.1080/0265203031000062091.
Organochlorine pesticides have been used in agriculture as a seed dresser, in sanitation, in malaria control programmes and in livestock to combat ectoparasites. Their residues accumulate in lipid-rich tissues due to their chemical stability and persistence. In the body they circulate throughout all compartments, deposit themselves in adipose fat and can be excreted during lactation. These pesticides are applied in tropical zones and drift to areas where cattle graze. Therefore, analyses of cow's milk samples can serve as an indicator of environmental and cows' exposure to them. One hundred and fifty milk samples were taken each year in 1998 and 2001 and analysed to determine concentrations of HCB, beta-HCH, pp"-DDE, op'-DDT and pp'-DDT. Results obtained indicate that beta-HCH is one of the main contaminants (0.106 and 0.087 mg x kg(-1) on fat basis) followed by pp'-DDT (0.078 and 0.037 mg x kg(-1) on fat basis) and pp'-DDE (0.051 and 0.033 mg x kg(-1) on fat basis). The HCB and op'-DDT were detected in lower quantities respectively (0.008 and 0.006 mg x kg(-1), and 0.031 and 0.010 mg x kg(-1) on fat basis). When comparing the results obtained with those from the previous study, it was noted that DDT levels decreased significantly in 2001 as a result of the substitution of the organochlorine insecticides with pyrethroids sprayed by the Mexican Ministry of Health to combat malaria since 1999.
有机氯农药曾在农业中用作拌种剂，也用于卫生、疟疾防治项目以及家畜身上以对抗体外寄生虫。由于其化学稳定性和持久性，它们的残留物会在富含脂质的组织中蓄积。在体内，这些农药会在所有组织中循环，沉积在脂肪中，并可在哺乳期排出。这些农药在热带地区使用，并会漂移到牛群放牧的区域。因此，分析牛奶样本可作为环境和奶牛接触这些农药的指标。1998年和2001年每年采集150份牛奶样本并进行分析，以测定六氯苯、β-六氯环己烷、对，对′-滴滴伊、邻，对′-滴滴涕和对，对′-滴滴涕的浓度。所得结果表明，β-六氯环己烷是主要污染物之一（以脂肪计分别为0.106和0.087毫克/千克），其次是对，对′-滴滴涕（以脂肪计为0.078和0.037毫克/千克）和对，对′-滴滴伊（以脂肪计为0.051和0.033毫克/千克）。六氯苯和邻，对′-滴滴涕的检测量较低（以脂肪计分别为0.008和0.006毫克/千克，以及0.031和0.010毫克/千克）。将所得结果与先前研究的结果进行比较时发现，由于自1999年以来墨西哥卫生部喷洒拟除虫菊酯替代有机氯杀虫剂来防治疟疾，2001年滴滴涕水平显著下降。
