Passive sampling of water and coastal air via semipermeable membrane devices

Lipid containing semipermeable membrane devices (SPMDs) were applied in a field sampling study of water and coastal air in California. SPMDs were shown to be effective in concentrating trace organochlorine contaminants from both air and water. Estimates of ambient air and water concentrations for selected organochlorines (OCs) were made from their concentrations in SPMDs. Comparison of the ratio of the estimated air to water OC concentrations to the non-dimensional Henryʹs Law constants suggests that the net flux of OCs should be from the ambient air to the water. In this study, SPMD values for coastal air concentrations were compared to those recently obtained by Iwata, Tanabe, et al., for measurements of OC air concentrations over the North Pacific ocean. SPMD derived estimates for coastal air concentrations of α and γ-HCCH were roughly 9 times higher than open ocean values; the cis- and trans-chlordanes were 70 times higher; and the p,p′-DDE levels are more than a thousand times higher. Coastal air concentration estimates for hexachlorobenzene were comparable to those previously reported for the open ocean. Comparison of OC ratios for open ocean air to those estimated for coastal air suggests the difference in the composition of coastal air is primarily due to an increase in γ-HCCH and a large increase in p,p′-DDE concentrations.