The relationship between site history and human health risks: Lessons from 13 years of contaminated land risk assessments in Victoria, Australia

Abstract

AbstractSite history is widely recognized as one of the key determinants of the nature and scale of contamination that is likely to be present at a location. While there is vast anecdotal and empirical evidence on the relationship between site history and risk of exposure to pollution, few attempts have been made to systematically collate data across sites to rigorously identify such trends. This study presents an analysis of human health risk metrics extracted from all 1732 contaminated land environmental audits published in Victoria, Australia between 2006 and 2018. The contaminating activities found to be most likely associated with elevated risks to human health were service stations, fuel depots, dry cleaners, gasworks, mechanical parts manufacturers, imported fill and unknown offsite sources generating regional groundwater pollution (usually polluted with trichloroethene). The ten chemical contaminants most frequently assessed in human health risk assessment reports included (in order): benzene, C>10–16 petroleum hydrocarbons, naphthalene, C6–10 petroleum hydrocarbons, xylenes, trichloroethene, toluene, ethylbenzene, benzo(a)pyrene, and tetrachloroethene. The findings of this report include recommendations to develop regulatory guideline values in Australia for trimethylbenzenes, heavy fraction petroleum hydrocarbons (C>16), and trans‐1,2‐dicholoethene, and to strengthen the evidence base informing risks associated with light fraction petroleum hydrocarbons (C6–16) and trichloroethene. To the author's knowledge, this study is the first to extract risk metrics from environmental audit reports and provides a strong evidence base to help regulators, academics and commercial practitioners rank and prioritize sites based on their site history and associated risks.