Thornton I, Abrahams P
Sci Total Environ. 1983 Jun;28:287-94. doi: 10.1016/s0048-9697(83)80026-6.
An estimated 4000 km2 of agricultural land in England and Wales has been contaminated in varying degrees by past mining and smelting activities. Contaminants include one or more of the metals Cu, Pb, Zn, Cd and As. Studies conducted in southwest and central England conclude that only a small proportion of these metals are taken up into the leaf material of pasture plants and that plant uptake would not seem to constitute a major pathway to grazing animals. Using the titanium content of faeces as a stable indicator of soil ingestion, we found that grazing cattle involuntarily ingest from 1% to nearly 18% of their dry matter intake as soil; sheep may ingest up to 30%. Soil ingestion varies seasonally and with farm management. Calculations based on soil, plant and faecal analyses show that from 9% to 80% percent of the Pb and 34% to 90% of the As intake into cattle on contaminated land is due to ingested soil.
据估计，英格兰和威尔士约4000平方公里的农业用地因过去的采矿和冶炼活动而受到不同程度的污染。污染物包括铜、铅、锌、镉和砷中的一种或多种金属。在英格兰西南部和中部进行的研究得出结论，这些金属中只有一小部分被牧场植物的叶片吸收，而且植物吸收似乎不是放牧动物摄入金属的主要途径。利用粪便中的钛含量作为土壤摄入量的稳定指标，我们发现放牧的牛在干物质摄入量中会非自愿地摄入1%至近18%的土壤；绵羊摄入的土壤量可能高达30%。土壤摄入量随季节和农场管理方式而变化。基于土壤、植物和粪便分析的计算表明，在受污染土地上，牛摄入的铅中有9%至80%、砷中有34%至90%是由于摄入土壤所致。
