Radioactive contamination from Fukushima was detected in bluefin tuna migrating through the Pacific. (Photo: stonybrook.edu/NOAA/FIS)
Radioactivity detected in tuna on California coast
Wednesday, May 30, 2012, 01:30 (GMT + 9)
A team of scientists from the universities of Stanford and Stony Brokk found that bluefin tuna (Thunnus thynnus) caught off the coast of California have relatively high levels of radioactivity from the Fukushima nuclear power plant, located in Japan.
However, in the study, published in the journal Proceedings of the National Academy of Sciences (PNAS), researchers make it clear that the level of contamination is not hazardous to people’s health.
The study authors analyzed 15 specimens caught in August 2011 on the California coast and compared their levels of radioactive isotopes with other tuna caught three years before.
The analysis results "unequivocally" reflected that the bluefin tuna are carrying radioactive particles from Fukushima from one extreme to the other in the Pacific Ocean, US experts point out.
The levels of 134-cesium and 137-cesium detected in fish were 10 times higher than those recorded in the samples of 2008, the newspaper El Mundo reported.
Anyway, the total radioactivity values -- about 10 becquerels per kilogram of fish -- are well below the maximum allowed for human consumption.
According to national regulations, the maximum allowable level ranges between 2,000 and 4,000 becquerels per kilogram.
The scientists, led by Daniel Madigan, a researcher at Stanford University, explain that "because the bluefin tuna is caught in the eastern Pacific for human consumption, the possibility of radioactive contamination arouses public concern."
"The concentrations of radioactive cesium in Pacific tuna that were presented are more than one order of magnitude below the safety limit that was recently changed in Japan, which is located at 100 becquerels per kilogram," they added.
The radioactive cesium does not sink quickly in water, so fish can swim through it and get contaminated in the process, BBC reported.
- 'Harmless' radiation found off Japanese coast
By Analia Murias