Lead mine waste: hazards to livestock

Waste from disused lead mines is used for a variety of purposes and has been implicated in outbreaks of lead poisoning in animals. Three outbreaks of lead poisoning, two in cattle and one in farm dogs, occurred in the south of Scotland. In the first outbreak, three housed suckler cows died and two were clinically affected but recovered after treatment. In the second, four heifers died and two recovered after therapy. Blood samples taken from cattle in both outbreaks contained lead in concentrations from 0 . 59 to 2 . 00 ppm (normal blood lead level 0 . 05 to 0 . 25 ppm). Post mortem examinations revealed signs of lead poisoning. Metallic particles in the rumens and abomasums of affected animals suggested mine waste as the source of the lead and subsequently it was found that the material had been used in the construction of a ramp over which silage was pushed (outbreak 1) and to fill potholes on the farm (outbreak 2). Covering the relevant areas with concrete prevented further occurrences. Farm dogs were affected over a period where mine waste was used to resurface a road. Two dogs died, six others showed signs of lead poisoning and others, with no clinical signs, had elevated blood lead levels.