Environmental and Molecular Mutagenesis (EMM) Editor's Choice - August 2014
The Editor's Choice for August is "Silver ions enhance UVB-induced phosphorylation of histone H2AX” by X. Zhao, T. Toyooka, and Y. Ibuki.
This Editor’s Choice article describes how combined exposures of human keratinocytes to silver ions and UVB radiation synergistically induce gamma-H2AX foci due to increased formation of UVB-induced cyclobutane pyrimidine dimers and (6-4) photoproducts. Silver is widely used in many different industrial and medical applications including the production of photovoltaic cells and panels, dentistry, and chemical manufacturing. It is also used in water purification systems in hospitals, community water systems, pools and spas because the catalytic action of silver with oxygen kills bacteria and algae and thereby eliminates the need for chlorine in these systems. The widespread use of silver ultimately results in increased levels of silver ions in our environment. Silver is considered to be an important water pollutant second only to mercury in its toxic effects on freshwater fish and invertebrates. While originally considered nontoxic, more recent studies point to possible health effects of silver on exposed human populations. Zhao and colleagues provide evidence for an interaction between silver ions and sunlight-induced DNA damage. Combining silver ions with exposure to UVB radiation (the carcinogenic component of sunlight), the authors found increased formation of key types of DNA damage associated with risk of sunlight-induced skin cancer. These studies highlight the potential for silver pollutants to enhance the carcinogenic effects of ultraviolet sunlight and thereby further increase the already growing rates of skin cancer observed world-wide. This study also underscores the need to investigate the genotoxic effects of complex mixtures containing both natural and man-made components in our environment. Environ. Mol. Mutagen. 55:556–565, 2014. © 2014 Wiley Periodicals, Inc.