Radiation, mutagenicity

Cellular oncogenes (VI) can be activated by amplification, by single point mutations, or by transposition. Slowly transforming retroviruses do not contain viral oncogenes but stimulate expression of cellular oncogenes by insertional mutagenicity. Radiation and chemical carcinogens also activate cellular onco-... 

A variety of mechanisms employing different enzymes repair damaged DNA, as after exposure to chemical mutagens or ultraviolet radiation. 

Iliakis G. 1984. The mutagenicity of alpha particles in ehrlich ascites tumor cells. Radiat Res 99 52-58. 

Base substitutions and frameshift changes occur spontaneously and can be induced by radiation and chemical mutagens. It is apparent that the molecular mechanisms resulting in these changes are different in each case, but the potential hazards associated with mutagens capable of inducing the different types of mutation are equivalent. 

In vivo mammalian mutation tests are not restricted to germ cell tests. The mouse spot test described below is, again, a test used first for studying radiation-induced mutation but has also been used for screening chemicals for in vivo mutagenic potential. This test has had several proponents but compared with in vivo chromosomal assays is not widely used. 

H. J. Muller s discovery in 1927 that radiation could induce mutations in living organisms. Whether congenital diseases such as Down s syndrome (in which an extra copy of a particular chromosome, or aneu-ploidy, is present) are much influenced by chemical mutagens in the environment remains an active area of study by genetic toxicologists. 

The supposition that ozone is mutagenic or carcinogenic in man is based primarily on information on the biochemical mechanism of ozone toxicity and to a lesser extent on in vitro and animal studies. The biochemical evidence is for the most part indirect and depends on an analogy between the free-radical nature of ozone toxicity and of radiation and other carcinogenic agents. 

W. K. Lutz, S. Vamvakas, A. Kopp-Schneider, J. Schlatter and H. Stopper, Deviation from additivity in mixture toxicity relevance of nonlinear dose-response relationships and cell line differences in genotoxicity assays with combinations of chemical mutagens and g-radiation. Environmental Health Perspectives Supplements, 2002,110(6), 915-918. 

The problem is that nuclear wastes contain radioactive isotopes that release life-threatening ionizing radiation that may pose a threat to humans and the environment for hundreds, thousands, or even millions of years. This radiation can cause carcinogenic, teratogenic, and mutagenic effects in small amounts and can result in radiation sickness and death in larger amounts. 

---