Using Trace Elements in Particulate Matter To Identify the Sources of Semivolatile Organic Contaminants in Air at an Alpine Site

An approach using trace elements in particulate matter (PM) to identify the geographic sources of atmospherically transported semivolatile organic contaminants (SOCs) was investigated. Daily samples of PM and SOCs were collected with high-volume air samplers from 16 January to 16 February 2009 at Temple Basin, a remote alpine site in New Zealand's Southern Alps. The most commonly detected pesticides were dieldrin, transchlordane, endosulfan I, and chlorpyrifos. Polycyclic aromatic hydrocarbons and polychlorinated biphenyls were also detected. For each sampling day, the relative contribution of PM from regional New Zealand versus long-range Australian sources was determined using trace element profiles and a binary mixing model. The PM approach indicated that endosulfan I, indeno[1,2,3-c,d]pyrene, and benzo[g,h,i]perylene found at Temple Basin were largely of Australian origin. Local wind observations indicated that the chlorpyrifos found at Temple Basin primarily came from the Canterbury Plains in New Zealand.