Emission of legacy chlorinated pesticides from agricultural and orchard soils in British Columbia, Canada.

Air samples were collected above agricultural fields in the Fraser Valley and orchards in the Okanagan Valley, British Columbia, Canada, to investigate volatilization of organochlorine pesticides used in the past. Concentrations of pesticides in air were elevated over soils that contained higher residues. Soil/air fugacity ratios at sites with the higher soil residues were calculated relative to air sampled at 40 cm height and background air.

Soil-air relationships for toxaphene in the southern United States.

Volatilization of toxaphene residues from agricultural soil was investigated at farms in the southern United States by collecting air samples 40 cm above the soil. The concentration of total toxaphene ranged over several orders of magnitude, from <3 to 6,500 ng g(-1) dry weight in soil, and <0.3 to 42 ng m(-3) in air.

Soil-air exchange of organochlorine pesticides in the Southern United States.

Soil samples were collected from 30 farms in Alabama, Louisiana and Texas during 1999-2000 to determine residues of organochlorine pesticides (OCPs). One or more of the DDT compounds (p,p'-DDT, o,p'-DDT, p,p'-DDD, p,p'-DDE, o,p'-DDE) was above the quantitation limit (0.1 ng g(-1) dry weight) in every soil, and toxaphene was above the quantitation limit (3 ng g(-1)) in 26 soils.

Chiral pesticides in soil and water and exchange with the atmosphere.

The enantiomers of chiral pesticides are often metabolised at different rates in soil and water, leading to nonracemic residues. This paper reviews enantioselective metabolism of organochlorine pesticides (OCPs) in soil and water, and the use of enantiomers to follow transport and fate processes. Residues of chiral OCPs and their metabolites are frequently nonracemic in soil, although exceptions occur in which the OCPs are racemic.