a half-life of eight days.
Radioactive cesium (cesium-137)has a half-life of 30 years.
Scientists are voicing concern about the potential long-term impacts from the cesium-137 being released from theplant, as well as the risk that contact with the most con-taminated water would lead to “immediate injury.”
Oneexpert, Kenya Mizuguchi, professor emeritus of MaritimeScience and Technology at Tokyo University, said, “We’reseeing the levels of radioactive materials in the water in-crease, which means this problem is going to continueto get worse and worse.”
No Safe Level
While much of the coverage of the impacts from thenuclear disaster are accompanied by reassurances aboutlow levels of exposure, there is no “safe” level of radiationexposure. The full impact of the Japanese nuclear crisis re-mains to be seen, but the health risks posed by radioactivecontamination are well-documented. In 2006, the National
-tion exposure that concluded that even low levels of radia-tion can cause human health problems, including cancer,and called for further investigation on potential links be-tween low-level radiation exposure and heart disease andimmune disorders.
Children are especially susceptible tothe impact of foodborne exposure to radioactive materials,making safeguards for food and water particularly critical.
Radiation in Fish
miles from the plant.
On March 29, 2011, a low level of
Chiba prefecture, south of Fukushima.
On April 1, 2011,before the proposed 3 million gallons of low-level radioac-
was caught approximately 40 miles from the plant withunsafe levels of iodine-131 and cesium-137.
Radiation and Marine Life
radiation. A 2000 study investigating radioactive materialin seaweed found traces of cesium-137 in two samples —one from Norway and the other from Japan.
The authorsof this study indicated that these levels might be a productof the radiation discharged from Chernobyl, 14 years afterthe accident.
Some algae have been shown to accumu-late radioactive iodine and technetium,
a metal that is abyproduct of nuclear reactors. The United States importedover 1.2 million pounds of seaweed and algae from Japanin 2010.
The accumulated level of cesium-137 in muscle tissue of whales has been used to trace the migratory patterns of individual animals.
In an animal weighing six tons, ce-sium-137 is likely to have a biological half-life of atleast six months.
Knowing this biological half-life, re-searchers are able to determine where an individual animalhas traveled and eaten prey from contaminated waters.
Food Chain Accumulation
Direct contact with water is a factor in the uptake of radio-active material for all seafood. But in addition to taking up
material in its body.
The discovery of radioactive material
higher up the food chain, like tuna.
native to Japan that is high on the food chain
) showedthat cesium-137 could be accumulated up the food chain,resulting in higher concentration of cesium-137 in the
Fish can expel radioactive material over time.
Ce-sium-137 can be retained in the muscle tissue of a living
biological retention half-life.
The range in biologicalretention half-life may be attributed to the temperature of
killed for market, it will not be able to expel the radioac-tive materials in the biological half-life timeframe and thecesium will break down as it would in the environment,with a 30-year half-life.
On April 5, 2011, the Japanese government established
from several locations were found to have detectablelevels of radiation.
2011, before the new regulations were established, would
The U.S. Response
In 2010, the United States imported 35.5 million poundsof seafood from Japan.
On March 22, 2011, the Food andDrug Administration (FDA) issued an import alert regardingall milk, milk products, fresh vegetables and fruits pro-duced or manufactured from the region near the nuclearplant, which means these products cannot enter the UnitedStates.
The FDA has said it will test seafood from theregion near the plant, but has not barred seafood fromentering the country.
Unfortunately, the FDA inspects 2percent of imported seafood on average every year,
call-ing into question how thorough the agency’s checks forradiation can be.