
Air Pollution Causes Sperm Mutations In Mice 53
Reservoir Hill writes "Epidemiological studies in humans have suggested a link between air pollution and reduced male fertility, but such studies are often confounded by other lifestyle differences such as diet, genetic background, and economic class. Now a study of mice, reared in cages kept in a shed downwind of two steel mills and a busy highway in a Canadian city, showed a host of genetic changes compared to similarly housed mice breathing filtered air. DNA in the sperm of the mice in the polluted area contained 60% more mutations, had more strand breaks, and had more bases that had been chemically modified via the addition of a methyl group. Precisely how the pollution caused the DNA damage remains unclear but changes may be a more general response to particulate pollution. 'It's important to move this forward to the next step: determining whether there are any human corollaries to this,' says Jonathan Samet, an epidemiologist at Johns Hopkins University."