Tracer-aided studies of the movement of toxic elements in soil-plant-water systems under controlled conditions

Techniques were developed and applied in a comparative study of the behaviour of arsenic and mercury in soil-plant-water systems in the context of soil contaminating toxic elements. The arsenic content of Saskatchewan soils ranged from 2 to 5 ppm. The results obtained suggested that arsenic adsorption by soil mica minerals would severely restrict the movement of arsenic in soils (e.g., into groundwater) under conditions of relatively low precipitation and near neutral pH. The mercury content of Canadian prairie soils ranged from 0.01 to 0.04 ppm. The results showed that relatively large amounts of mercury can be added to soils as HgCl2, HgSO4, or phenyl mercuric acetate (fungicide) and that subsequent accumulation by such representative crops as alfalfa, rape, wheat and rutabegas will be small, apparently as a result of a root barrier. (author)