PAHs: Legacy Pollutants with Emerging Concerns in Aquatic Systems Session at the SETAC North America 2010 Annual Meeting
Judy Crane (Minnesota Pollution Control Agency), Peter Van Metre (U.S. Geological Survey) and Greg Sower (ENVIRON)
Polycyclic aromatic hydrocarbons (PAHs) comprise a class of legacy pollutants that persist in the environment and pose risks to animals, plants, and people at elevated concentrations. PAHs are present in sediment as mixtures and typically co-occur with other contaminants. Although PAHs represent a well known environmental problem in aquatic sediments, new concerns are emerging about urban sources of PAHs and toxic mechanisms of action of PAHs in aquatic biota. To this end, the PAH Work Group of the SETAC Sediment Advisory Group (SEDAG) proposed this session and combined forces with an independently proposed oxy-PAH session to yield a well-attended platform session at the SETAC North America conference in Portland, OR. Three general areas of PAH research were highlighted in this session: (1) toxicity of PAHs to aquatic life in key environmental settings, (2) occurrence of substituted PAHs in air and water, and (3) the importance of coal tar-based pavement sealcoat as a source of PAHs to urban water bodies and air.
This session highlighted emerging research on the sources and effects of PAHs, and linked some of the research to environmental management actions. The information presented should give new impetus for other researchers in the field and update environmental managers on recent developments in assessing risks associated with PAHs and the importance of a major, recently identified source―coal tar-based pavement sealcoat.
A major highlight of the session was the presentation by Colleen Greer of Queen’s University, titled “Toxicity of Chemically Dispersed Crude Oil to Atlantic Herring (Clupea harengus) Embryos.” Congratulations to Colleen for winning a Best Student Platform Award, Masters Student, for her incredibly timely talk, given the Deepwater Horizon oil spill in the Gulf of Mexico. The other talk dealing directly with toxicity, by John Weinstein (The Citadel), was equally fascinating, exploring the synergistic effects of PAHs and piperonyl butoxide (PBO), a commonly used adjuvant in pyrethroid pesticides, on photo-induced toxicity of PAHs to grass shrimp larvae. Two talks and one poster presented cutting-edge research on the occurrence of oxygen-substituted PAH compounds in the environment. Shawn Fisher (U.S. Geological Survey) and co-authors showed the potential for an unintended consequence of a groundwater remediation strategy to reduce PAH transformation―the formation of oxy-PAH that are potentially more mobile in groundwater. Julie Layshock presented an interesting study of her Ph.D. research at Oregon State University on oxy-PAHs in the air in Beijing, China during the Olympic Games, focusing on the potential of long-range transport of particulate-bound oxy-PAHs. Shirin Fallahtafti’s poster presented her Master’s research at Queens University suggesting that the oxy- and oxy-alkyl-substituted PAHs may be more toxic to Japanese medaka than the unsubstituted parent compounds.
The last four talks in this session summarized the “state of understanding” of the occurrence, transport, and fate of PAHs from use of coal tar-based pavement sealcoat. Talks by Barbara Mahler and Peter Van Metre (both of the U.S. Geological Survey) showed that coal tar-based sealcoat is the largest source of PAH contamination, on average, to 40 urban lakes studied and can also result in contamination of the indoor environment and of urban air. Alison Watts (University of New Hampshire) presented research from a 2-year field-scale study of the effect of coal tar-based sealcoat use on increased PAH loading in stormwater runoff and on PAH contamination of soils and runoff treatment structures adjacent to sealed parking lots. Finally, Judy Crane (Minnesota Pollution Control Agency) presented an overview of how the state and several Minnesota cities have responded to the identification of coal tar-based sealcoat as an important source of PAH contamination in stormwater ponds. Together, these talks provide a fine example of linking environmental science to the management of sustainable environmental quality.
Authors’ contact information: firstname.lastname@example.org, email@example.com and GSower@environcorp.com
Additional information on the importance of coal tar-based sealcoat as a source of PAHs to urban environments is provided at the following web sites:
Please contact Judy Crane at firstname.lastname@example.org to join the SEDAG PAH Work Group. General information about SEDAG is available on the SETAC Web page at http://ww2.setac.org/node/35. The SEDAG Communities portal is open to all SETAC members and guests who select SEDAG in their SETAC User Profile. Information on accessing the portal is available at http://ww2.setac.org/node/156.
Return to the Globe