EFFECTS OF TEMPERATURE AND WIND DIRECTION ON THE ATMOSPHERIC CONCENTRATIONS OF ALPHA-ENDOSULFAN

The atmospheric concentrations of endosulfan (a contact insecticide) were measured for 14 months in Bloomington, IN, at an average frequency of three times per month. Meteorological conditions were also measured during that period. Endosulfan was collected on polyurethane foam plugs with a high-volume air sampler and was analyzed by electron capture, negative ionization, gas chromatographic mass spectrometry. The average concentration of alpha-endosulfan over the 14-month period was 86 pg/m3 (3.8 x 10(-12) Torr), and the highest concentration was 890 pg/m3. Multiple linear regression was used to relate the meteorological conditions with the atmospheric concentration. Variables used in the regression were inverse temperature and wind direction. This model showed a high effect of atmospheric temperature and a moderate effect of wind direction. The heat of vaporization calculated from these data was 95 +/- 13 kJ/mol.