States Urge EPA To Use Range Of 'Attenuation Factors' For Vapor Intrusion

Several state regulators are criticizing EPA's vapor intrusion database as unsuitable for estimating "meaningful attenuation factors" -- mathematical tools used to estimate the risk that toxic vapors will rise into a building -- and are asking the agency to provide a range of acceptable attenuation factors rather than one "generic" one. Providing a range of attenuation factors would give states more flexibility to make their own estimates based on site-specific factors, state officials say. Criticism of "EPA's Vapor Intrusion Database:...