Health impacts of large releases of radionuclides. Interactions with human nutrition and other indices of population health.

The consumption of food is an important pathway involved in the internal contamination of humans. The site-related critical foodstuffs can be grouped into three main categories: dairy products; aquatic animals, such as fish, molluscs and crustaceans; and other typical foods. The concentration factor plays a more important role than the amount of a certain food consumed. Semi-natural and natural ecosystems are of special interest in this context because they can provide critical pathways for radionuclide transfer to humans, and they can also act as temporary sinks or long-term sources for radionuclides deposited from the atmosphere. From the viewpoint of population health, another important role is played by the countermeasures. The reference values commonly adopted in radiation protection are conservative and they have been established for planning practices that could provide future sources of irradiation. After a large release of radionuclides, the evaluation of the problem must be as realistic as possible, otherwise the countermeasures will imply consequences worse than those produced by the accident itself (without any further intervention). This criterion was clearly stated by the International Commission on Radiological Protection but it was frequently neglected after the Chernobyl accident. The results of a survey on the number of induced abortions following this incident are reported. These suggest that moral and ethical problems are involved above and beyond any economical implications.