Health risk assessment of inhaled oil spill emissions with and without adding dispersant (due to volatile organic compounds)

We performed laboratory measurements to record concentration of different volatile organic compounds (VOCs) emitted from a crude oil slick before and after premixing with dispersant. We input these concentrations into a health risk assessment model to estimate the cancer risk and hazard quotients based on USEPA-designated measures and reference concentrations. We targeted the health risk assessment of cleanup workers or residents nearby. Based on the results, the cancer risk of exposure to toluene and benzene reduced from 74 and 57 excess lifetime cancer cases per million for one hour per day of exposure continuing for 3 months to 66 and 37 (11% lower) excess lifetime cancer cases per million. Dispersant addition was effective in emission reduction of the lighter VOCs (up to 30% lower emission rate). However, hazard quotients of the non-carcinogenic VOCs even after dispersant addition were 2 to 3 orders of magnitude greater than 1 meaning that there are serious concerns about exposure to these VOCs.