Seafood Contamination after the BP Gulf Oil Spill and Risks to Vulnerable Populations: A Critique of the FDA Risk Assessment

Article excerpt

BACKGROUND: The BP oil spill of 2010 resulted in contamination of one of the most productive fisheries in the United States by polycyclic aromatic hydrocarbons (PAHs). PAHs, which can accumulate in seafood, are known carcinogens and developmental toxicants. In response to the oil spill, the U.S. Food and Drug Administration (FDA) developed risk criteria and established thresholds for allowable levels [levels of concern (LOCs)] of PAH contaminants in Gulf Coast seafood.

OBJECTIVES: We evaluated the degree to which the FDA's risk criteria adequately protect vulnerable Gulf Coast populations from cancer risk associated with PAHs in seafood.

DISCUSSION: The FDA LOCs significantly underestimate risk from seafood contaminants among sensitive Gulf Coast populations by failing to a) account for the increased vulnerability of the developing fetus and child; b) use appropriate seafood consumption rates; c) include all relevant health end points; and d) incorporate health-protective estimates of exposure duration and acceptable risk. For benzo[a]pyrene and naphthalene, revised LOCs are between two and four orders of magnitude below the level set by the FDA. Comparison of measured levels of PAHs in Gulf seafood with the revised LOCs revealed that up to 53% of Gulf shrimp samples were above LOCs for pregnant women who are high-end seafood consumers.

CONCLUSIONS: FDA risk assessment methods should be updated to better reflect current risk assessment practices and to protect vulnerable populations such as pregnant women and children.

KEY WORDS: BP oil spill, children's health, Deepwater Horizon, Food and Drug Administration, Gulf of Mexico, PAHs, polycyclic aromatic hydrocarbons, risk assessment, seafood. Environ Health Perspect 120:157-161(2012). http://dx.doi.org/10.1289/ehp. 1103695 [Online 12 October 2011]

The Gulf of Mexico is a very productive sh cry, comprising the majority of domestic shrimp (60%) and oyster (70%) production (Louisiana Seafood Promotion & Marketing Board 2010). During the BP Deep water Horizon oil spill, > 200 million gallons of oil poured into the Gulf of Mexico, followed by 1.8 million gallons of dispersants intended to break down the oil into droplets (Repanich 2010).

The U.S. Food and Drug Administration (FDA) is the agency responsible for determining seafood safety. In response to the oil spill, the FDA, working with the states and the National Oceanic and Atmospheric Administration (NOAA), initially closed approximately 37%/b of the Gulf of Mexico (225,290 [km.sup.2]) to commercial and recreational fishing (NOAA 2010). Reopening of these areas was conducted on a rolling basis, using a two-phase testing regime consisting of organoleptic testing, in which experts sniff pieces of seafood for oil taint, and chemical analysis for polycyclic aromatic hydrocarbons (PARs) (FDA 2010a). PARs arc found in crude oil and have the potential to accumulate in aquatic organisms, presenting a health risk via ingestion of contaminated seafood (Yender et al. 2002). Crustaceans and mollusks, such as shrimp, crab, and oysters, are especially likely to be contaminated because of reduced rates of biological clearance of PAHs in these species (Law et al. 2002). The FDA tested for the presence of 13 PAHs selected on the basis of known carcinogenicity or other health effects, including stunted growth, anemia, and kidney disease. The FDA also calculated allowable thresholds [levels of concern (LOCs)] For PARs in each specific type of Gulf seafood.

The FDA allowed most Gulf fisheries to reopen during the summer and fall of 2010 based on measured PARs in seafood below the LOCs, although public confidence in Gulf seafood was slow to rebuild (Marcus 2011). The adequacy of the policy decision to resume commercial fishing hinged on the accuracy of FDA's assumptions in calculating the LOCs and on the rigor of the seafood monitoring program. By critically evaluating the FDA's risk assessment and monitoring practices, we aimed to determine the adequacy of public health protection in this particular case and to identify any broader improvements that may be needed to risk assessment practices and food safety determinations at the FDA. …