Representative Edward Markey (D-MA), chair of the Energy and Environment Subcommittee in the House Energy and Commerce Committee, which is leading the congressional investigation into the BP oil spill, sent a letter to U.S. Food and Drug Administration (FDA) Commissioner Margaret Hamburg this week concerning the safety of Gulf seafood.

Markey’s letter is a follow-up to a letter he sent in May requesting information relating to the potential impacts on seafood safety from the prolonged use of chemical dispersants on oil flowing out of the Deepwater Horizon oil well.  In it he states, “Although I have yet to receive any response to my letter, new developments that seem to indicate that the marine food chain in the Gulf of Mexico has already been contaminated by oil and arsenic raise new questions about the impact that this catastrophic oil disaster will have on marine life in the Gulf waters.”

seafood-platter-featured.jpgWhile the National Oceanic and Atmospheric Administration (NOAA) continues to increase the area of federal waters closed to fishing, samples of crab larvae have tested positive for hydrocarbons.  Markey says that this is, “a major concern given that crab is a favorite food for both humans and multiple fish species that live in the marshes.”

Markey fears that predators that eat oil-tainted food like crab or crab larvae will swim into areas that are not closed to fishing and that those predators will enter the human food supply.

Another concern he voices is that the amount of arsenic in Gulf waters is increasing as more and more oil continues to spill.  A study published by a team from Imperial College London earlier this month revealed that oil spills can partially block the ocean’s ability to naturally filter arsenic out of seawater.

According to a press release issued by the Imperial College London team, “High levels of arsenic in seawater can enable the toxin to enter the food chain and can disrupt the photosynthesis process in marine plants and increase the chances of genetic alterations that can cause birth defects and behavioral changes in aquatic life.  It can also kill animals such as birds that feed on sea creatures affected by arsenic.”

The researchers found that oil spills can partially block the ocean’s natural filtration system and prevent it from naturally cleaning arsenic out of seawater.  The scientists say this shutdown of the natural filtration system causes arsenic levels in seawater to rise, which means that it can enter the marine ecosystem, where it becomes more concentrated and the further it moves up the food chain.

According to the Centers for Disease Control and Prevention, arsenic is found in both organic and inorganic forms in nature.  Inorganic arsenic is typically used in industry, in copper chromated arsenate-treated lumber, and in private well water in some parts of the country.  Organic arsenic is found in many foods–particularly shellfish such as bivalves (clams, oysters, scallops, mussels), crustaceans (crabs and lobsters), and certain cold water and bottom feeding finfish, and seaweed or kelp.  Organic forms of arsenic found in seafood are generally considered to be nontoxic, and are excreted in urine within 48 hours of ingestion; however, a 2007 study found high levels of inorganic arsenic in hijiki seaweed.

Non-cancer effects of arsenic exposure can include thickening and discoloration of the skin, stomach pain, nausea, vomiting, diarrhea, numbness in hands and feet, partial paralysis, and blindness.  Arsenic has been linked to cancer of the bladder, lungs, skin, kidney, nasal passages, liver, and prostate.

Markey asks Hamburg to provide answers to a number of questions regarding seafood safety with regards to both hydrocarbon and arsenic contamination by July 28.  Among them are:

1.  What is FDA doing to assess whether the ingestion of contaminated species by other more mobile fish is not resulting in the contamination of marine seafood caught outside the areas closed to fishing?

2.  While FDA’s Webpage states that “FDA and NOAA have agreed on a protocol to determine when closed federal harvest waters can be re-opened.”  The protocol relies heavily on the ability to pass a sensory and chemical analysis to identify oil and its residues.  Does this protocol also identify when seafood is contaminated with arsenic?

3.  How does FDA plan on monitoring the long-term effect that oil, other hydrocarbons, and other toxic compounds such as arsenic have on aquatic life in the Gulf of Mexico and any potential effect that consumption of seafood from the Gulf has on human health?

4.  Will FDA continue to conduct long-term monitoring for arsenic to ensure that the chemical does not bioaccumulate in the food chain for months or years after the leak has stopped and the oil is visibly removed?

5.  What federal standards are in place for how much arsenic can be present in seafood consumed by humans?