Healthy from the Start : Building a Better Basis for Environmental Health Standards — Starting with Radiation

T he last half century has seen great progress in environmental health protection. As part of this progress there has been a growing awareness that the focus must be the protection of those most at risk. The protection of children, in particular, has grown significantly in prominence. In the United States for example, There has also been a great deal of progress in radiation protection .known as the BEIR committee) have all made significant contributions by developing age-specific and sex-specific dose and risk factors. However, regulations have generally not kept pace with the overall trend in environmental health protection or with important developments in the scientific understanding of radiation risks. In fact, as our knowledge has grown, the gaps in the regulatory framework have become more evident. For example, many U.S. regulations remain focused on estimating the dose received by a hypothetical Radiation exposures in utero can lead to a heightened risk of cancer and other ill-health effects, yet most radiation protection standards still are based on " Reference Man, " a hypothetical adult male. art of the inspiration for IEER's project to reorient radiation standards to the protection of those most at risk came from a simple realization about the simplest radionuclide, tritium. Tritium is a form of radioactive hydrogen with two neutrons in the nucleus. Ordinary hydrogen has no neutrons while deuterium, a stable isotope of hydrogen, has one neutron. All three hydrogen isotopes behave almost the same chemically. Therefore tritium (T) can replace hydrogen to form tritiated water (i.e. HTO or T 2 O). 2 Tritium decays via the emission of a beta particle , and is thereby transformed into a stable isotope of helium (He-3). With a relatively short half-life of 12.3 years, tritium is highly radioactive. For example, one gram (approximately the weight of a quarter of a teaspoon of salt) of tritium in tritiated water will contaminate