Contamination of seafood by radioactivity produced from burning of coal and other fossil fuels

The environmental impact of radioactivity produced from fossil fuel combustion is investigated. A brief review is given of previous work. The latest calculation of the Oak Ridge group shows that a power plant using coal, which contains 1 ppm of U and 2 ppm of Th, gives a radioactive dose comparable to, or greater than that of a nuclear reactor, even if the dust is removed by up to 99%. A review of the experimental data is given. It is emphasized that 210Pb and 210Po, because of their volatility, are expected to be released at much higher rates than other radioactivities and that they are strongly concentrated in marine organisms so that their effect on the Japanese living on seafood may be considerable. An estimate is made for the hazard of 210Po through the foodchain of marine organisms. Although the uncertainties are still very large, the effect of 210Po on the Japanese is found to be significant. The collective dose of a 1,000 MW coal-fired power plant in Japan is estimated to be 320 - 16,000 man-rem/year, which should be compared with 20 man-rem/year in the results of the Oak Ridge group, which do not include this foodchain. Comparison with nuclear energy is made. Although the absolute value of the coal-fired power plant is still much smaller than the natural background, its maximum value is three times as large as the total fuel cycle of the full-scale nuclear electricity generation, so its social implications cannot be overlooked. (author)