Screening the potential for hydrocarbon vapour intrusion risks

Risk assessments are a widely accepted practice used by regulatory agencies to determine the conditions under which a chemical may pose a significant risk to human health and safety. Vapour intrusion is often the principal risk driver at sites where petroleum hydrocarbons have been released into the grounds. Current screening criteria for identifying such potential risks are conservative. The conservatism exists because aerobic biodegration, as significant hydrocarbon vapour attenuation mechanism, is not considered in screening level risk assessments. Aerobic biodegration is likely to occur at all sites with low-level sources of petroleum products and its consideration would result in the screening out of most sites from further, unnecessary, risk assessment. Here, the Energy Institute's Soil, Water and Waste Working Group outlines recent work in this field.