Soil contamination in the environment of intensive farming units

Abstract Bacteriological and chemical analyses of soil samples were carried out in the vicinity of animal houses. Areas of 100 m radius around the houses were sampled at 400 points and the concentrations of vegetative bacteria, nitrogen, organic carbon, coliform bacteria, enterococci, thermophilic bacteria, Clostridium perfringens , ammonia, chloride, spore-forming bacteria, nitrifying bacteria and nitrates were determined. These features were grouped as being indicative of recent or more long-term pollution. The pattern of pollution did not greatly differ with type of animal being housed, although pollution tended to be highest in the vicinity of pig houses. Pollution was mainly confined to a radius of 50 m from the housing. Chlortetracycline (CTC)-resistant Escherichia coli were found in the vicinity of houses where CTC was included in feeds.