Development and calibration of a resin-based passive sampling system for monitoring persistent organic pollutants in the atmosphere

Responding to a growing need for inexpensive and simple monitoring of persistent organic pollutants (POPS) in the atmosphere, a passive air sampling technique based on the sorption of gaseous pollutants to the sampling resin XAD-2, a styrene-divinylbenzene copolymer, has been developed. A quantitative understanding of the uptake kinetics of the passive air samplers (PAS) was obtained through a combination of field calibration studies, controlled wind tunnel experiments, and flow field simulations. Forty-two PAS were deployed for varying time periods up to I yr at three calibration stations in the Laurentian Great Lakes region and the Canadian High Arctic with ongoing conventional air sampling of organochlorine pesticides. The PAS take up quantifiable levels of POPs within a few weeks of deployment, and the amount of chemical collected increases steadily over a 1-yr sampling period. The uptake of POPs by the PAS is controlled by molecular diffusion and independent of wind velocity. The time-averaged air concentrations of organochlorine pesticides derived from the PAS data are comparable with those from HiVol sampling. This study suggests that the XAD-2 resin-based PAS can be used to derive at least semiquantitative information on the vapor-phase concentrations of POPS in the atmosphere and are suitable for the measurements of long-term average concentrations at the levels occurring in remote regions.