ing a system to monitor the oil spill’s effects, the federal government anticipates that it will be better able to predict future exposures, to mitigate the damage from past and ongoing exposures, and to ensure care for those affected, said John Howard. Using a proposed “bull’s-eye” model (see Figure 2-1), Howard categorized the types and levels of exposure by proximity to the oil source. The different subpopulations include workers at or near the plume, clean-up workers on the water, clean-up workers on the beach, affected communities, and the general public.

Exposure to oil freshly released into the environment poses more risks than exposure to oil closer to shore. Referencing Overton’s remarks (see Chapter 1), Howard explained that oil moving from the wellhead to the surface contains compounds such as volatile organic compounds (VOCs), explosive vapors, and methane. Dispersants are also more concentrated in the area where oil moves from the wellhead to the surface. As a result, workers nearer the point of origination are more likely to be exposed to higher levels of VOCs. For instance, clean-up workers on vessels drilling relief wells may be at higher risk for inhaling VOCs than workers on vessels laying boom or skimming oil-contaminated waters nearer to shore. And workers directly involved with burning oil will be exposed to higher concentrations of combustion products, heat, and rare flash fires.

Clean-up efforts on land are as varied as those on the water, leading to a wide variety of exposures, stated Howard. Workers charged with shoreline cleanup are exposed to weathered oil, contaminated beaches, and prolonged exposure to heat. Workers and volunteers involved with removing oil from contaminated vessels and personal protective equipment and cleaning and caring for oil-soiled birds, turtles, and other wildlife before relocation could also be exposed to weathered oil. Finally, response and remediation workers involved in the disposal and recycling of hazardous solid and liquid wastes could be exposed to the wastes that the other workers are managing.

Residents in the affected communities are also at risk for dermal exposure to either crude oil in the water or weathered oil on the beach; inhalational exposure to chemicals or compounds, such as those carried ashore by prevailing winds; or ingestion by eating potentially contaminated seafood, drinking contaminated water, or other forms of ingestion. Although oil and other related chemicals may be less concentrated in residential areas, affected communities are already wrestling with

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