Sunday, March 17, 2013
Japan - More Fukushima Cancer Deaths Than Predicted, Study
Scientists warn that the number of cancer deaths resulting from the Fukushima disaster could be closer to 1,000 than the 125 predicted.
Scientists have warned that the number of cancer deaths resulting from the Fukushima nuclear power plant disaster could be closer to 1,000 than the 125 predicted.
Studies that quantify the health consequences of radiation exposure remain controversial, due in part to the uncertainty of the mathematical models and assumptions used. Here, a team from Princeton University has revealed that long-term effects of the nuclear accident are likely to be worse than a previous prediction by John Ten Hoeve and Mark Jacobson (TH&J) from Stanford University.
By considering the gamma-ray dose from land contaminated with cesium-134 and cesium-137, the Princeton team found that the TH&J projection of 125 future cancer-related deaths globally may be an underestimate. This was because long-term doses from radiocesium in the environment were not considered by TH&J in their analysis. Being the first to quantify the worldwide impacts of the Fukushima radiation, TH&J concluded that there were no significant public health effects.
Radiation-induced cancer usually takes several decades to develop. Ionizing radiation first damages the DNA in our cells, and if these cells do not get repaired by DNA repair machinery, they accumulate further errors leading to a higher risk that cancers such as leukemia may develop.
As radiocesium is absorbed by the soil or deposited into streams, the researchers expect a prolonged presence of radiocesium in the air, water, and food after the Fukushima accident. Radiocesium persists as long as 2.4 to 38 years, according to a previous assessment of the Chernobyl accident. In contrast, TH&J based their analysis on the assumption that radiocesium disappears with a half-life of 14 days.
While there are some uncertainties in their calculations of the long-term radiocesium dose, the researchers believe that the number of future cancer mortality is likely to be closer to 1,000 than to 125.
The article can be found at: Beyea J et al. (2013) Accounting for long-term doses in “Worldwide health effects of the Fukushima Daiichi nuclear accident.