|June 25, 2012
Conservative estimates indicate that the 2010 BP oil disaster released over 200 million gallons of oil into the Gulf, followed by at least 1.8 million gallons of dispersants.
While the use of dispersants helped mitigate the public relations disaster by preventing the persistent formation of surface oil, as well as keeping many beaches visibly untouched, they also drove the oil deeper into the water column (and food chain) rendering a 2-dimensional problem (surface oil) into a 3-dimensional one. Additionally, research indicates that dispersants prevent the biodegradation of toxic oil components, as well as increasing dispersant absorption into fish from between 6 to 1100 fold higher levels.
Since the event, both the mainstream media and the government have acted as if the oil disappeared, and that no significant health risks remain for the millions still consuming contaminated seafood from the Gulf.*
Now, a new study published in the journal Environmental Health Perspectives has revealed that the 2010 BP Gulf oil disaster resulted in widespread contamination of Gulf Coast seafood with toxic components from crude oil.1 In fact, levels of polycyclic aromatic hydrocarbons (PAHs) in shrimp were found to exceed the FDA’s established thresholds for allowable levels [levels of concern (LOCs)] for pregnant women in up to 53% of Gulf shrimp sampled.
PAHs are well-known carcinogens and developmental toxicants, which is why the U.S. Food and Drug Administration (FDA) is obligated to set risk criteria and thresholds for allowable levels of exposure to them.**
In the new study the authors set out to evaluate the degree to which the FDA’s procedures for determining the safety of Gulf seafood after the BP disaster reflect the current risk assessment guidelines and practices, as produced by other authoritative entities, including the National Research Council (NRC), the World Health Organization (WHO), the U.S. Environmental Protection Agency (EPA) and the California EPA. The authors focused on cancer risk associated with shellfish consumption, looking at whether or not the FDA’s guidelines protect the most vulnerable populations, e.g. pregnant women, infants.
The authors discovered a glaring discrepancy between the FDA Gulf seafood risk assessment (FDA 2010a) and the FDA’s own prior practice with risk assessment guidelines produced by other authoritative entities.
The FDA’s risk assessment was found to be seriously flawed because of the following six questionable assumptions:
The questionable assumptions include six main issues: a) high consumer body weight, b) low estimates of seafood consumption, c) failure to include a cancer risk assessment for naphthalene, d) failure to adjust for early-life susceptibility to PAHs, e) short exposure duration, and f) high cancer risk benchmarks. Taken together, these flaws illustrate a failure to incorporate the substantial body of evidence on the increased vulnerability of subpopulations to contaminants, such as PAHs, in seafood.
Environmental risk assessment requires the use of scientifically founded assumptions and appropriate default estimates about the exposed population, the intensity and duration of exposure, and the dose–response relationship. The risk assessment methods used by the FDA to set safe exposure levels for Gulf Coast seafood after the oil spill do not incorporate current best practices and do not protect vulnerable populations. The FDA’s conclusions about risks from Gulf seafood should be interpreted with caution in coastal populations with higher rates of seafood consumption and in vulnerable populations such as children, small adults, and pregnant women. Our analysis demonstrates that a revised approach, using standard risk assessment methods, results in significantly lower acceptable levels of PAHs in seafood and identifies populations that could be at risk from contaminants in Gulf Coast seafood. Health advisories targeted at high-end consumers would better protect vulnerable populations such as pregnant women, women who may become pregnant, and children. Our approach did not address infant exposure to PAHs via maternal seafood consumption and lactational transfer. The NRC (2008) found up to 50-fold interindividual variability in cancer risk and recommends incorporation of estimates of uncertainty, as well as population risk distributions, into future risk assessments. Improved public health protection from contaminants in food will require reforming FDA risk assessment practices.
Taken together, these findings demonstrate that the FDA’s conclusion that there are no significant risks to Gulf populations from oil spill–related contaminants in seafood are incorrect, and reckless when it comes to the health of the most vulnerable populations.
With reports now surfacing in mainstream media outlets on the appearance of eyeless shrimp and mutant fish, this latest finding probably only scratches the surface of a health problem in the Gulf titanic in proportions.
1 Seafood contamination after the BP Gulf oil spill and risks to vulnerable populations: a critique of the FDA risk assessment. Environ Health Perspect. 2012 Feb ;120(2):157-61. Epub 2011 Oct 3. PMID: 21990339
*Sixty percent of domestic shrimp and 70% of domestic oysters are sourced from the Gulf.
**The inherent absurdity of determining "an acceptable level of harm" is often overlooked
Additional Reading: Deformed Gulf Seafood is Part of the Deepwater Horizon Legacy