Volatilization of weathered chiral and achiral chlordane residues from soil

To mitigate the impact on the environment of persistent organic pollutants (POPs), we must understand thoroughly their environmental fate. Residues of many of these pollutants are still present in soil years after their legitimate uses were banned. In this report, the volatilization of one such persistent pollutant, chlordane, from a field where it was applied approximately 40 years ago, is examined in detail overthe course of several years. Ambient air samples were collected at three heights above the treated soil throughout the investigation. Air samples were also collected at several background sites in Connecticut for comparison. Analysis of these samples shows that chlordane volatilization from soil continues to occur long after initial application, at rates dependent on both temperature and cultivation of the soil. Comparison of relative concentrations and enantiomeric profiles for components of technical chlordane in atmospheric samples from a variety of sources suggests a regional, urban input of chlordane to the ambient air over Connecticut, possibly related to the widespread termiticidal use of chlordane in home foundation soils.