The presence and cycling of pesticides in the ecosphere

Biological transfer and loss of /sup 36/Cl-labeled DDT in an old-field ecosystem

“…DDT and other organochlorine insecticides are present in the atmosphere world-wide, even in places remote from the nearest point of pesticide application (Antommaria et al 1965;Tatton and Ruzicka 1967;Risebrough et al 1968;Woodwell et al 1971;Edwards 1973). DDT enters the atmosphere via direct drift during the application process (Abbott et al 1966;Pionke and Chesters 1973;Spencer 1975), volatilization from treated soils (Abbott et al 1966; Pionke and Chesters 1973; Gerakis• and Sficas 1974;Spencer 1975), possible codistillation with water (Acree et al 1963;Bowman et al 1965;Risebrough et al 1968;Gerakis. and Sficas 1974), and with wind blown dust particles from soil surfaces containing DDT residues (Cohen and Pinkerton 1966;Pionke and Chesters 1973;Spencer 1975).…”

“…Residues have been reported in places as remote from the use of DDT as Antarctica (George and Frear 1966;Peterle 1969). Once deposited on the earth's surface by rain or snow, DDT is again removed and transported to other areas, primarily by surface run-off (Chisholm and Koblitsky 1959;Hindin et al 1966;Sparr et al 1966;Freed 1970;Pionke and Chesters 1973;Willis and Hamilton 1973;Gerakis and Sficas 1974). The DDT transported by run-off is mainly associated with the particulate matter and not the water itself (Freed 1970;Pionke and Chesters 1973;SBdergren 1973;Holden 1975).…”

“…Even though DDT is relatively insoluble in water (Bowman et al 1960;Metcalf 1971;Woodwell et al 1971), once into the water systems, it is very persistent (Lichtenstein and Schulz 1961), probably because of its adsorption to particulate matter. Organochlorine insecticides are generally considered to be non-leachable in soils; hence, very little contamination of ground waters occurs (Bowman et al 1965;Sparr et al 1966;Guenzi and Beard 1967;Freed 1970;Pionke and Chesters 1973;Willis and Hamilton 1973;Gerakis and Sficas 1974;Achari et al 1975).…”

Pesticide Monitoring in the Prairies of Western Canada

“…Water transport of pesticides is chiefly through surface runoff, which may cause contamination of lower-lying areas and of water bodies (Gerakis and Sticas, 1974).…”

“…Most pesticides are insoluble or slightly soluble in water and therefore tend to accumulate in bottom sediments, with the result that concentrations in sediments are generally much higher than in the surrounding water. Gerakis and Sticas (1974) report that the accumulation of pesticides in bottom sediments play an important role in the disappearance of pesticides from contaminated water. They support this by stating that studies in major agricultural river basins in California revealed that an average pesticide concentration of 0.1 parts per billion (ppb) to 0.2 ppb in river water may mean that bottom sediments contain 20 ppb to 100 ppb.…”