Tuna exposed to radioactive contamination detected

By now, you have seen the reports that tuna exposed to radioactive debris from the Japan nuclear disaster, have migrated across the ocean to California.

Unfortunately, you might think it is much worse if you just read a headline, such as this one from a blog on the Wall Street Journal website: Swimming to a Sushi Shop Near You: Radioactive Tuna? (http://blogs.wsj.com/japanrealtime/2012/05/29/swimming-to-a-sushi-shop-near-you-radioactive-tuna/)
But most all agree, including the authors of the study, that the levels of radioactivity pose little risk.

From Madigan, etal (2012) Pacific bluefin tuna transport Fukushima-derived radionuclides from Japan to California, PNAS (www.pnas.org/cgi/doi/10.1073/pnas.1204859109)

“Radiocesium concentrations of post-Fukushima PBFT reported here were more than an order of magnitude below the recently changed Japanese safety limit of 100 Bq kg−1 wet wt (about 400 Bq kg−1 dry wt)….
Thus, even though 2011 PBFT [post reactor exposed fish] showed a 10-fold increase in radiocesium concentrations, 134Cs and 137Cs would still likely provide low doses of radioactivity relative to naturally occurring radionuclides, particularly 210Po and 40K.”
 Clearly, scientists will continue to monitor seafood including a larger study this summer. But this is no reason to stop eating tuna.

Radiation and the Food Supply

In light of the leakage from Japan’s nuclear facilities following the tsunami, questions have been raised regarding the safety of the US food supply.   Based upon the government reports, there is currently no risk to the US food supply.  This includes fallout here in the US from radiation released into the atmosphere and foods imported from areas with the potential for higher exposure.

EPA has only detected miniscule amounts of radiation in milk that can be attributed to the Japanese disaster, but these were so small that they pose no threat to human health.  The levels found were 5000 times lower than the level set by FDA.  Considering that and having a half-life of 8 days, there are currently no reasons to avoid drinking milk.

Radioactive material gets into milk when those materials drop from the atmosphere onto grasses which are then eaten by cow.  The EPA and FDA have increased the level of monitoring food, drinking water, and rainwater.  There have been a number of monitoring stations throughout the US that have detected some levels, but this was expected.  However, the levels seen must be put in perspective.

According to the EPA “Drinking water samples from two locations, Boise, Idaho and Richland, Washington, showed trace amounts of Iodine-131 – about 0.2 picocuries per liter in each case. Even an infant would have to drink almost 7,000 liters of this water to receive a radiation dose equivalent to a day's worth of the natural background radiation exposure we experience continuously from natural sources of radioactivity in our environment.”

FDA has said that no food is being exported from the affected area, and they are monitoring imported products from other areas of Japan, and at this point, there has not been any radiation detected.  In addition, the US imports very little food from Japan.  It is estimated that only 4% of our imported food comes from Japan.

There is specific concern with seafood with higher levels of radioactive materials making its way into the US.  Besides blocking seafood from the infected areas, FDA has increased its monitoring seafood coming into the US and state that there is no risk related to seafood.

http://www.fda.gov/newsevents/publichealthfocus/ucm247403.htm