New Applications For Passive Samplers PDF Download

Passive sampling devices (PSDs) were used to measure air vapor and water dissolved phase concentrations of polycyclic aromatic hydrocarbons (PAHs) and oxygenated PAHs (OPAHs) at two different environmentally contaminated sites. Environmental contaminates like PAHs and OPAHs are present in both the atmospheric and aqueous environmental compartments. It is known that PAHs can move between the atmospheric and aqueous environmental compartments via diffusion, this contaminate transport process is referred to as diffusive air-water exchange (flux). The flux of OPAHs has not been quantitatively assessed, but would be expected to similarly exchange between air and water. The objective of this work was to assess flux of both PAHs and OPAHs in two unique environmental scenarios. The first study deployed PSDs at four coastal sites in the Gulf of Mexico prior to, during and after shoreline oiling from the Deepwater Horizon incident (DWH). Environmental concentrations for 33 PAH and 22 OPAH were calculated from PSDs deployed at each site over a 13 month period, and flux of 13 PAHs across the water-air boundary was determined. This is the first report of vapor phase air concentrations and flux of both PAHs and OPAHs during the DWH incident. Vapor phase sum PAH and OPAH concentrations ranged between 6.6 and 210 ng/m3 and 0.02 and 34 ng/m3 respectively. PAH and OPAH concentrations in air exhibited different spatial and temporal trends than in water, and flux of individual PAHs was shown to be at least partially influenced by the Deepwater Horizon incident. Phenanthrene was in deposition prior to shoreline oiling in Louisiana and after shoreline oiling the flux direction switched to volatilization, at over 10,000 (ng/m2)/day. This study presents additional evidence of the DWH incident contributing to air contamination, and provides one of the first quantitative flux determinations with passive sampling technology. The second study used PSDs to measure 60 PAHs and 22 OPAHs in the air and water to quantitatively assess flux in a river system that contains a Superfund Mega-site, and passes through residential, urban and agricultural land. The magnitude of PAH flux was greater at sites near or within the Superfund Mega-site than outside of the Superfund Mega-site. The largest individual PAH deposition was naphthalene at a rate of -14,200 (ng/m2)/day, this flux occurred at a sampling site two tenths of a mile upstream of the designated Superfund site area. Human health risk associated with inhalation of vapor phase PAHs and dermal exposure to PAHs in water were also assessed. Excess lifetime cancer risk (ELCR) estimates show potential increased risk associated with exposure to PAHs at sites within and in close proximity to the Superfund Mega-site. Specifically, estimated ELCR associated with inhalation of vapor phase PAH was above 1 in 1 million within the Superfund Mega-site. Superfund sites are often suspected sources of air pollution due to legacy sediment and water contamination. This second study shows that the majority of PAHs in the water are from airborne sources. This suggests that the river water in this Superfund Mega-site is predominantly a sink for airborne PAHs, rather than a source. This dissertation highlights the potential to use passive sampling in novel ways in order to better understand contaminant transport in impacted eco-systems, and fill in data gaps in health risk assessments by investigating chemicals in multiple environmental compartments.