Establishing Eco-SSLs for PAHs: Lessons Revealed from a Review of Literature on Exposure and Effects to Terrestrial Receptors

Polycyclic Aromatic Hydrocarbons (PAHs) were among the top priority Constituents of Potential Concern (CoPC) in the United States Environmental Protection Agency's (USEPA's) effort to set ecological soil-screening (Eco-SSL) values. Search strategies, acceptance criteria, and evaluation procedures were developed to address effects on plants, invertebrates, and wildlife. Systematic literature searches were conducted to obtain all relevant information on toxic response of terrestrial plants, invertebrates, and wildlife exposed to PAHs. More than 325 papers on PAHs were reviewed. Only 14 papers (one plant, three invertebrate, and ten wildlife) met the minimum criteria for use. Only eight PAH analytes had data that qualified for use in deriving Plant-, Invertebrate-, or Wildlife-SSLs. Only one SSL, (invertebrate, fluorene) could be derived based on the available data using the USEPA draft criteria. Rapid volatilization of lower molecular weight PAHs, generally low toxicity of persistent PAHs, limited potential for uptake by plants, binding to soil organic matter that lowers bioavailability, and low bioaccumulation by invertebrates may explain the general absence of documented adverse effects among terrestrial receptors exposed to PAHs.