Your News story “Chernobyl: poverty and stress pose 'bigger threat' than radiation” (Nature 437, 181; 200510.1038/437181b) suggests that the health and environmental effects of the Chernobyl accident were not as great as originally suggested.

Writing on behalf of an international group of researchers in this area (see, we believe that these suggestions, based on the reports of the UN Chernobyl Forum, are misleading.

As we approach the twentieth anniversary of the Chernobyl disaster we should be sensitive to the long-term implications. T. A. Mousseau and colleagues

The full estimate, given by the UN report, of people who could eventually die of factors linked to radiation includes people in other contaminated areas as well as those within Soviet Contaminated Zones and is 9,335, not 4,000 as reported. This estimate is similar to earlier estimates of future cancer mortality prepared by the US government in December 1987 (Report on the Accident at the Chernobyl Nuclear Power Station, US Nuclear Regulatory Commission, Washington DC). Further details to support our argument that neither of these estimates should be down played are available at the website above.

We believe it is too early to assess the overall impacts of radionuclide exposure on human health or on plant and animal populations. In particular, we do not know all the possible consequences of the multi-generational accumulation of genetic defects. As we approach the twentieth anniversary of the Chernobyl disaster we should be more sensitive to the long-term implications rather than suggesting that the coast is clear for redevelopment in the contaminated zones.

Up to now, most studies have focused on cancer, because of funding constraints, with little investment in studies of non-cancer morbidity or model systems. But model organisms with relatively short lifespans may provide a clear picture of the multigenerational consequences for human health, while humans exposed to Chernobyl are a unique population that must be supported and observed far into the future.

Given the long latency period for many diseases and the growing interest in rejuvenating the nuclear power industry, it is imperative that studies of the affected populations continue.