Liu Z P
College of Animal Husbandry and Veterinary Medicine, Yangzhou University, Yangzhou, Jiangsu 225009, PR China.
Sci Total Environ. 2003 Jun 20;309(1-3):117-26. doi: 10.1016/S0048-9697(03)00011-1.
The diagnosis of lead poisoning combined with cadmium in sheep and horses living on farmland in the vicinity of non-ferrous metal smelters in Baiyin of Gansu province in China was based on laboratory findings as well as clinical signs. The concentrations of lead, cadmium, copper and zinc in soils, water, forages, feed and blood, hair and tissues of affected sheep and horses were determined in the surroundings of the smelters in Baiyin and controls. Haematological values were also measured. The concentrations of these elements in soils, forages, water and feed were significantly higher than those in the control area (P<0.01). The contents of lead and cadmium were 9.3 and 690 times in forages, respectively, 10 and 35.6 times in feed. The concentrations of lead and cadmium in blood, hair and tissues of the affected sheep and horses were significantly higher than reference values and control animals (P<0.01). The occurrence of anaemia in affected animals belonged to a hypochromic and microcytic pattern. Lead and cadmium intake levels, estimated according to the ingestion rates of forages, illustrates that the apported lead and cadmium through the ingestion of vegetation growing in the closest sites to the smelters were approximately 6.0 mg Pb/kg body wt./day and 1.1 mg Cd/kg body wt./day in horses, 21.4 mg Pb/kg body wt./day and 4.0 mg Cd/kg body wt./day in sheep, surpassing the fatal dosages for horses of 1.7 mg Pb/kg body wt./day and for sheep of 4.4 mg Pb/kg body wt./day and 1.0 mg Cd/kg body wt./day. It is, therefore, suggested that the disease of sheep and horses in this region is caused by lead poisoning combined with cadmium, mainly due to environment heavy metal pollution by industrial activity. Meanwhile, as such levels of contamination in animal food and grain pose a significant potential risk to human health, these results have formed the basis for subsequent research on levels of metal contamination in human tissues from affected populations. Thus, it can be seen that knowledge of lead and cadmium concentrations in livestock in this region is important for assessing the effects of pollutants on domestic animals themselves and contaminant intakes by humans.
对生活在中国甘肃省白银市有色金属冶炼厂附近农田的绵羊和马的铅镉中毒诊断是基于实验室检查结果以及临床症状做出的。测定了白银冶炼厂周边及对照地区土壤、水、草料、饲料以及患病绵羊和马的血液、毛发和组织中的铅、镉、铜和锌浓度，还测量了血液学指标。这些元素在土壤、草料、水和饲料中的浓度显著高于对照地区（P<0.01）。草料中铅和镉的含量分别是对照地区的9.3倍和690倍，饲料中分别是10倍和35.6倍。患病绵羊和马的血液、毛发和组织中的铅和镉浓度显著高于参考值和对照动物（P<0.01）。患病动物的贫血属于低色素小细胞型。根据草料摄入量估算的铅和镉摄入量表明，在距离冶炼厂最近地点生长的植被中，马通过摄食摄入的铅和镉分别约为6.0毫克/千克体重/天和1.1毫克/千克体重/天，绵羊分别为21.4毫克/千克体重/天和4.0毫克/千克体重/天，超过了马的致死剂量1.7毫克/千克体重/天以及绵羊的致死剂量4.4毫克/千克体重/天和1.0毫克/千克体重/天。因此，认为该地区绵羊和马的疾病是由铅镉中毒引起的，主要是由于工业活动造成的环境重金属污染。同时，由于动物食品和谷物中的此类污染水平对人类健康构成重大潜在风险，这些结果为后续研究受影响人群人体组织中的金属污染水平奠定了基础。由此可见，了解该地区家畜体内铅和镉的浓度对于评估污染物对家畜自身的影响以及人类的污染物摄入量很重要。
