Increasingly, health risk assessment is addressing multiple pathway exposures to multiple contaminants. In the present study, the authors reviewed aggregated exposure and cumulative risk approaches for contemporary and ubiquitous semivolatile organic compounds (SVOC). 22 studies aggregating exposure pathways were identified, and 31 cumulating risk. Exposure aggregation is based on the addition of pathway-specific doses, using kinetic modelling where it exists, and classic external dose equations otherwise. In most cases, exposure is dominated by a single route or source of exposure -mainly the oral pathway – via dietary or non-dietary exposure. Preferential routes and sources of exposure are influenced by SVOC physical-chemical properties such as vapor pressure. The cumulative risk approach for contaminants is based on dose addition. Simple sum of hazard quotient (Hazard Index: HI) is the most commonly used cumulative risk assessment approach, while Relative Potency Factor (RPF) appeared to the best suited – although this calls for a level of toxicological information that limits the number of compounds that can be studied simultaneously. Where both were performed, moving from HI to more refined approach produced similar results. In conclusion, both approaches – exposure aggregation and cumulative risk – rely on simple assumptions. Nevertheless, they allow uncertainty to be reduced, in comparison with source-by-source or chemical-by-chemical approaches.
Authors: Pelletier M, Bonvallot N, Glorennec P. ; Full Source: Environmental Research. 2017 Jul 18; 158:649-659. doi: 10.1016/j.envres.2017.06.022. [Epub ahead of print]