Atmospheric transport of toxaphene from the southern United States to the Great Lakes Region.
Toxaphene was used extensively as an insecticide on cotton in the southern United States until its use was restricted in 1982. Toxaphene has been found in the water and fishes from the Great Lakes, and several authors have qualitatively linked this observation to atmospheric transport from the southern United States, although no detailed field study has been done to confirm this suggestion. We implemented a sampling network to measure the gas-phase concentrations of toxaphene near Lake Michigan at Sleeping Bear Dunes, MI; Bloomington, IN; Lubbock, TX; and Rohwer, AR. The toxaphene concentrations referenced to 288 K were 11 +/- 1, 25 +/- 1, 160 +/- 3, and 950 +/- 30 pg/ m3, respectively. We combined these concentration data with a nonparametric, backward trajectory, multiple regression model of the following form: ln(P) = a0 + a1/T + a2theta where P is the partial pressure of toxaphene (in atm) in a given sample, T is the atmospheric temperature at the sampling site during sampling (in degrees Kelvin), and theta is 0 if the backward trajectory comes from the north and 1 if the trajectory comes from the south. The parameters of this model were generally significant, giving a temperature coefficient (a1) corresponding to 45 +/- 8 kJ/mol and a positive directional coefficient (a2) of 0.6 +/- 0.2 (except for Texas, which was not significant). The positive sign and magnitude of the directional coefficient indicates that the sources of toxaphene are located south of the sampling sites. We also compared the chemical behavior of toxaphene in the atmosphere and found that the congener ratios were similar at the different sampling sites but slightly different from various toxaphene standards.
James
Ryan R
RR
Environmental Science Research Center, School of Public and Environmental Affairs and Department of Chemistry, Indiana University, Bloomington 47405, USA.
Hites
Ronald A
RA
D000392:Air Movements; D004784:Environmental Monitoring; D004785:Environmental Pollutants / Q000032:analysis*; D008401:Gas Chromatography-Mass Spectrometry; D006114:Great Lakes Region; D007306:Insecticides / Q000032:analysis*; D013696:Temperature; D014112:Toxaphene / Q000032:analysis*; D014481:United States
D004785:Environmental Pollutants; D007306:Insecticides; D014112:Toxaphene