Environmental DNA Damage

Ionization radiation is common in our environment. Radiation sources for human exposure include radon, rocks, and soil in some areas, cosmic radiation and medical/ 

The cation radical can react with another molecule such as DNA, initiating a chain reaction. 

DNA suffers radiation damage by both a direct mechanism and an indirect mechanism. The direct damage results from radiation-induced ionization of DNA itself. The indirect damage results from attack on DNA by other free radicals. Since water is the predominant molecule in cells, the major source of indirect radiation DNA damage is from water radiolysis. 

In the presence of oxygen, the released electron reacts quickly with it to form a superoxide radical. 

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Wellejus, A., Dalgaard, M., and Loft, S. (2002). Oxidative DNA damage in male Wistar rats exposed to di- -bntyl phthalate. Journal of Toxicology and Environmental Health—Part A 65, 813-824. 

The maintenance of the integrity of the information in DNA molecules is of utmost importance to the survival of a particular organism as well as to survival of the species. Thus, it can be concluded that surviving species have evolved mechanisms for repairing DNA damage occurring as a result of either replication errors or environmental insults. 

Costa M, Christie NT, Cantoni O, ZelikofF JT, Wang XW, Rossman T. 1991. DNA damage by mercury compounds an overview. In Suzuki T, Imura N, Clarkson TW, editors. Advances in mercury toxicology — Rochester Series on Environmental Toxicity. New York (NY) Plenum Press, p. 255-273. 

Chen, L. and Dixon, K., Analysis of repair and mutagenesis of chromium induced DNA damage in yeast mammalian cells and transgenic mice, Environmental, Health Perspective, 106, 1027-1032, 1998. 

To develop methods to identify individual or population susceptibility to environmental carcinogens, focusing on regulatory mechanisms for metabolism of carcinogens or repair mechanisms for carcinogen induced DNA damage between individuals or populations. 

Duty SM, Singh NP, Silva MJ, Barr DB, Brock JW, Ryan L, Herrick RE, Christiani DC, Hauser R (2003) The relationship between environmental exposures to phthalates and DNA damage in human sperm using the neutral comet assay. Environ Health Perspect 111 1164-1169... 

Genotoxicity may also be tested with a Mutatox test (Azur Environmental Ltd., Berkshire, England), using a dark mutant strain of bioluminescent bacterium V. fischeri [54]. DNA-damaging substances are recognized by measuring the ability of a test sample to restore the luminescent state in the bacterial cells. The authors pointed to the sensitivity of the test to chemicals that damage DNA, bind DNA, or inhibit DNA synthesis. 

Mutagenic activity. Smoke of cured leaf, in broth culture was active on Salmonella typliimurium . Environmental cigarette smoke, administered by whole-body to p53 mutant (UL53-3 x A/J)Fj mice of both genders for up to 9.5 months, produced similar oxidative DNA damage in lung and heart of both mutants and wild-type littermate con-... 

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