Carcinogens are present in fossil fuel emissions, particularly those from coal combustion, but there is no information on their public health effects. In the past, under less stringent occupational standards, workers exposed to coal emissions suffered increases in cancer rates. In coal-based synthetic fuel processes, many carcinogens may arise, but with careful plant design it should be possible to attain a very low occupational risk. In the products themselves, most carcinogens will remain with the heavy residues, and synthetic gas and distillates should present little cancer risk to the general public. For residual liquid fuels, including those derived from-shale, close control of emissions within plants and releases to the atmosphere will be necessary. Such heavy fuels would be used in large industrial boilers and power plants, where the necessary occupational safeguards could be applied.
Coal (especially certain lignites) contains varying concentrations of uranium, and its combustion releases radioactivity into the atmosphere.24 The solid wastes from coal combustion can also be a source of radiation. These radiation effects are generally thought to be less important than those from uranium mining.
Third, too little is known about the heritable genetic effects in man of either ionizing radiation or fossil fuel emissions to permit a comparison. Both agents have demonstrable mutagenic activity in laboratory tests. By extrapolation from such results, the Risk and Impact Panel estimated that a 1-GWe nuclear plant, for each year of its operation (with the associated fuel supply) might induce 0.5 severe genetic defects, but places little confidence in the figure. No estimate is feasible for coal.*
Risks of low-probability, high-consequence accidents are associated chiefly with nuclear reactors, hydroelectric dams, and transportation and storage of liquefied natural gas (LNG). The subject of nuclear reactor accidents has been extensively studied, especially by the Reactor Safety Study (WASH-1400),25 commissioned by the Nuclear Regulatory Commission. This study concluded that over the long term, the expected health damage from nuclear accidents (treated as probability of event times consequences per event) is smaller than that from radiations emitted in routine operation. This conclusion may not be decisive in the public appraisal of nuclear power, however, because some people may have a much greater fear of very infrequent but great nuclear accidents than they have of events that cause comparable totals of illnesses and deaths spread over long periods of