Air-water exchange of PAHs and OPAHs at a superfund mega-site

Abstract

Chemical fate is a concern at environmentally contaminated sites, but characterizing that fate can be difficult. Identifying and quantifying the movement of chemicals at the air-water interface are important steps in characterizing chemical fate. Superfund sites are often suspected sources of air pollution due to legacy sediment and water contamination. A quantitative assessment of polycyclic aromatic hydrocarbons (PAHs) and oxygenated PAH (OPAHs) diffusive flux in a river system that contains a Superfund Mega-site, and passes through residential, urban and agricultural land, has not been reported before. Here, passive sampling devices (PSDs) were used to measure 60 polycyclic aromatic hydrocarbons (PAHs) and 22 oxygenated PAH (OPAHs) in air and water. From these concentrations the magnitude and direction of contaminant flux between these two compartments was calculated. 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 net individual PAH deposition at a single site was naphthalene at a rate of −14,200 (±5780) (ng/m2)/day. The estimated one-year total flux of phenanthrene was −7.9 ×105 (ng/m2)/year. Human health risk associated with inhalation of vapor phase PAHs and dermal exposure to PAHs in water were assessed by calculating benzo[a]pyrene equivalent concentrations. Excess lifetime cancer risk estimates show potential increased risk associated with exposure to PAHs at sites within and in close proximity to the Superfund Mega-site. Specifically, estimated excess lifetime cancer risk associated with dermal exposure and inhalation of PAHs was above 1 in 1 million within the Superfund Mega-site. The predominant depositional flux profile observed in this study suggests that the river water in this Superfund site is largely a sink for airborne PAHs, rather than a source.

Analytical progress and challenges for the detection of oxygenated polycyclic aromatic hydrocarbon transformation products in aqueous and soil environmental matrices: A review

“…At the same time, it is expected that currently unidentified oxygenated PAH compounds will continue to emerge as relevant factors impacting site risk and management, and continued collaboration which supports sharing of compound mass spectral libraries and reference compounds will be needed. Santos et al, 2017Qiao et al, 2014Tidwell et al, 2017 (Siemers et al, 2015), or more variable response to OPAH (Qiao et al, 2013) • Recovery of PAH may be improved by the inclusion of C18 column in the protocol (Motorykin et al, 2015) Lichrolut EN Siemers et al, 2015 Motorykin et al, 2015 OHPAH, PAH deconjugated urine C. Additional nonpolar sorbents : Cyclohexyl, Phenyl, C8…”

“…A substantial body of evidence now challenges the commonly-held assumption that because of their greater polarity, mobility, and bioavailability, oxygenated PAH are inherently more quickly degraded in the environment and are therefore less concerning than parent PAH (Lundstedt et al, 2007). Concentrations of OPAH that exceed parent PAH have been reported by several studies in both soil and water matrices (Bandowe et al, 2014;Brorström-Lundén et al, 2010;Kurihara et al, 2005;McKinney et al, 1999;Tidwell et al, 2017;Wilcke et al, 2014b). In several cases, studies have also demonstrated lower removal rates of some, though not all, of these compounds compared to the parent PAH (Hu et al, 2014), or have demonstrated similar stability to PAH under common environmental conditions (McKinney et al, 1999).…”

Determination of PCB fluxes from Indiana Harbor and Ship Canal using dual-deployed air and water passive samplers

“…Increasingly, passive sampling techniques are used to estimate the air-water exchange of SVOCs. For example, air-water exchange of PCBs and PAHs have been determined in the Lower Great Lakes (Liu et al, 2016), the Lower Duwamish waterway, Washington (Apell and Gschwend, 2017), the Gulf of Mexico (Tidwell et al, 2016), and the Willamette River, Oregon (Tidwell et al, 2017). These studies found that a passive sampling approach improves the spatial resolution, as well as allows direct determination of the freely-dissolved phase of the compounds both in the air and water compartments.…”

Removal of 1,4-Naphthoquinone by Birnessite-Catalyzed Oxidation: Effect of Phenolic Mediators and the Reaction Pathway

“…Polycyclic aromatic hydrocarbons (PAHs) are contaminants that are commonly found in water, soil, and airborne particulates and are converted into various toxic derivatives upon degradation [ 1 , 2 , 3 ]. Natural weathering, photolysis, and biochemical transformations afford oxygenated PAHs (OPAHs) [ 4 , 5 , 6 , 7 ]. On the basis of detailed soil pollutant analyses, Sehlin [ 8 ] concluded that the natural weathering of contaminated soil can result in the OPAH and PAH contents remaining at high levels for long periods; it was also demonstrated that the incomplete biochemical degradation and conversion of PAHs in contaminated soil or water leads to OPAH generation and accumulation.…”