The newly-developed passive air sampling (PAS) system provides inexpensive and simple monitoring of persistent organic pollutants in the atmosphere (see Wania et al. 2003). A "passive" air sampler is a device that collects chemicals from the atmosphere without the help of a pump. The PAS is based on the sorption of gaseous pollutants to a sampling resin (XAD-2 - a styrene-divinylbenzene copolymer, i.e. a plastic material). The sampler consists of a stainless steel mesh cylinder filled with resin. The cylinder is suspended in an inverted galvanized steel can with an open bottom. The polymer resin absorbs pollutants carried in the air - contaminants are taken up in the resin by molecular diffusion from the atmosphere.
Image: Wania et al., 2003