Passive-sampler derived air concentrations of persistent organic pollutants on a north-south transect in Chile

Passive air samplers consisting of polyurethane foam (PUF) disks, were deployed in six locations in Chile along a north-south transect to investigate gas-phase concentrations of polychlorinated biphenyls [PCBs), organochlorine pesticides (OCPs), and polybrominated diphenyl ethers (PBDEsI. The study provides new information on air concentrations of these persistent organic pollutants (POPs) which is lacking in this region. It also provides insight into potential sources and long-range transport (LRT). The samplers were deployed for a 2-month period in five remote sites and one site in the city of Concepcibn. Mean concentrations [pg m-" for ZPCB were 4.7 f 2.7 at remote sites and 53 f 13 in Concepcibn. PCB levels at remote sites were related to proximity to urban source regions andlor air back traiectories. With the exceotion of endosulfan I. mean concenfrat.ons Ipg m31 of OCPS at bacaround s tes were consistentlv ow: 5.4 + 1.4forii-HCh. 7.0 g1.1 for y-HCH, 2.5 1 0 . 5 f o ; ~ ~ , 2.5 f 0.6 for CC, ' 1.9 I 1.2 for dieldrin, and less than 3.5 for toxaphene. Endosulfan I showed a decreasing concentration gradient from 99 to 3.5 pg me3 from the north to south of Chile. Concentrations of OCPs inthe Concepcibn Clwere generally 10-20times higher than atthe backgroundsitessuggesting continued usage andlor re-emission from past use. For instance, at remote sites, the d y ratio (0.76) was typical of background air, while the ratio in Concepcibn (0.12) was consistent with fresh use of y-HCH. Levels of XPBOEs were below the detection limit of 6 pg m-3 at al1 sites.