A Review of Seafood Safety after the Deepwater Horizon Blowout

Abstract

Background: The Deepwater Horizon (DH) blowout resulted in fisheries closings across the Gulf of Mexico. Federal agencies, in collaboration with impacted Gulf states, developed a protocol to determine when it is safe to reopen fisheries based on sensory and chemical analyses of seafood. All federal waters have been reopened, yet concerns have been raised regarding the robustness of the protocol to identify all potential harmful exposures and protect the most sensitive populations.Objectives: We aimed to assess this protocol based on comparisons with previous oil spills, published testing results, and current knowledge regarding chemicals released during the DH oil spill.Methods: We performed a comprehensive review of relevant scientific journal articles and government documents concerning seafood contamination and oil spills and consulted with academic and government experts.Results: Protocols to evaluate seafood safety before reopening fisheries have relied on risk assessment of health impacts from polycyclic aromatic hydrocarbon (PAH) exposures, but metal contamination may also be a concern. Assumptions used to determine levels of concern (LOCs) after oil spills have not been consistent across risk assessments performed after oil spills. Chemical testing results after the DH oil spill suggest PAH levels are at or below levels reported after previous oil spills, and well below LOCs, even when more conservative parameters are used to estimate risk.Conclusions: We recommend use of a range of plausible risk parameters to set bounds around LOCs, comparisons of post-spill measurements with baseline levels, and the development and implementation of long-term monitoring strategies for metals as well as PAHs and dispersant components. In addition, the methods, results, and uncertainties associated with estimating seafood safety after oil spills should be communicated in a transparent and timely manner, and stakeholders should be actively involved in developing a long-term monitoring strategy.

Science in support of the Deepwater Horizon response

“…An independent assessment arrived at the same conclusion (43). Nevertheless, public perceptions about seafood safety continued throughout the event and beyond.…”

Federal seafood safety response to the Deepwater Horizon oil spill

“…For the LOC calculations, to ensure a health protective approach (in addition to using cancer and noncancer values that are designed to be conservative values), the FDA used the 90th percentile of the national consumption data reported in the National Health and Nutrition Examination Survey for fish, shrimp, and shellfish for calculating risk and then adjusted the 90% meal size to account for the number of meals eaten by a 90th percentile consumer to ensure protection for low-through high-level consumers. Nevertheless, some concerns were raised with regard to the seafood consumption rates used by the FDA to calculate the PAH LOCs for the DWH seafood assessment (16). For example, a 2010 Natural Resources Defense Council survey of 547 people living in Louisiana, Alabama, Mississippi, and Florida showed that the average shrimp median daily consumption rate among residents was 3.6 times higher (48 g/d) than the FDA estimated shrimp consumption rate of 13 g/d (17).…”

Consequences of oil spills: a review and framework for informing planning

“…In terms of physical health, direct contact with crude oil, or indirect contact through, for example, inhalation of vapors or consumption of tainted seafood can cause deleterious health effects ranging from dizziness and nausea to certain types of cancers and issues with the central nervous system (Jenssen 1996 (Binet et al 2002, Aguilera et al 2010, they have been linked, in addition with volatile organic compounds (VOCs), with causing severe DNA degradation, cancers, birth and reproductive defects, irreversible neurological and endocrine damage, and impaired cellular immunity , Aguilera et al 2010, Major and Wang 2012. Volatile organic compounds are often used as diluents in oil transport and processing and are considered to be the main pollutants in crude oil with varied health effects depending on the type and amount of chemical(s) used in the operation (Goel 2011). …”

“…In that event, VOCs evaporated and became airborne within hours, causing hundreds of residents within a mile of the spill to be evacuated for acute health symptoms (NTSB 2010). Vaporized toxins pose a threat to human health (Binet et al 2002, Gosselin et al 2010, Kelly et al 2010, Goel 2011, McLinden et al 2012. This, combined with dense human population, suggests that a bitumen spill in Burrard Inlet can potentially have unprecedented impact on human health.…”