Gulf seafood: Assessing its safety
By Jennifer Nelson, M.S., R.D. and Katherine Zeratsky, R.D.
Since the April 2010 Deepwater Horizon oil spill, people frequently ask me about the safety of Gulf seafood. Although the total amount of oil that flowed into the Gulf of Mexico is not known, there is consensus that many thousands of gallons escaped daily. The chemicals in the oil — and in the dispersant used to break up the oil — are of concern for the Gulf fish and shellfish, and for us.
Two compounds in particular are of concern: polycyclic aromatic hydrocarbons (PAHs) and dioctyl sodium sulfosuccinate (DOSS). There are more than 100 different PAHs and they come from many sources including crude oil — some even occur when you charbroil meat. When breathed, consumed or when in contact with skin at toxic levels some PAHs have been linked to tumors and birth defects. DOSS is a detergent-type dispersant that has been used for past oil spills. It has been associated with health problems in cleanup workers and with marine-life toxicity.
Numerous government agencies, including the Food and Drug Administration, the National Oceanic and Atmospheric Administration, and the Environmental Protection Agency, are involved in monitoring the effects of this disaster. Here are some of the steps they’ve taken to ensure seafood safety:
- Closure of areas affected by the spill and precautionary closures in zones nearby.
- Close monitoring of water and aquatic life from oil-tainted and untainted areas.
- Testing of seafood products at processing plants in the Gulf and seizure of exposed food products. Oysters, crabs and shrimp are specifically targeted because they retain contaminants longer than finfish.
- Upgrading of testing methods. Interestingly, sensory testing (aka “sniffing”) has been used to test for crude oil and hydrocarbon compounds. More specific laboratory methods have been updated to speed up detection of PAHs. Tests that had taken up to one week now show results in as little as 48 hours.
- A new test for DOSS. Testing of previous and new samples of seafood from throughout the Gulf show trace amounts of dispersants — well below safety limits for both seafood and humans.
I’m relieved that progress has been made and that we’re relying on something more sophisticated than sniffing for contaminants. It’s also good to know that there is a system in place to continuously test waters, fish and seafood, and to keep affected areas locked down.
It’s difficult to forecast how long the effects of the spill will last in terms of our environment — and our food system. At this time, I’m OK recommending Gulf seafood to “average consumers” — adults who might eat Gulf seafood occasionally. It seems that the risks are low, and occasional meals can help offset the economic hardship Gulf coast citizens face.
However, a more cautious approach is probably appropriate for “vulnerable” people — those for whom food safety is always a concern, such as pregnant and lactating women and their infants, young children, and those who are immune compromised. These groups are more vulnerable because smaller amounts of contaminants can have dramatic effects due to altered body processes and lower levels of tolerance.
I’ll also expand this list to include those living near the Gulf who are most likely not “average consumers” and probably eat seafood from nearby waters on a nearly daily basis. Testing and levels of safety are often set based upon average consumption patterns.