Air pollution can cause mutations

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Science Matters by David SuzukiScience Matters is published weekly in newspapers across Canada. To postyour comments about this week's topic, or others, please visit ourdiscussion forum.Air pollution can cause mutationshttp://www.davidsuzuki.org/about_us/Dr_David_Suzuki/Article_Archives/weekly12200201.aspShorterLink: http://shorterlink.com/?RQDQU2Six years ago, scientists found that herring gulls living near steel millsaround the harbour in Hamilton, Ontario tended to have high DNA mutationrates. These mutations were then transferred to the next generation ofgulls, increasing the offspring's chances of developing genetic diseaseslike cancer and birth defects. Researchers suspected at the time that airpollution was causing the mutations, but they couldn't eliminate otherfactors, such as polluted water or contaminated fish, that also could havebeen responsible.Last week, scientists published a paper indicating that air pollution isindeed the likely culprit behind the mutations. What's more, there's noreason why human DNA should be immune from the same pollution. So our genesmay also be damaged and inherited by our children. It's sobering to thinkthat chemicals in our air affect us at a genetic level. Few studies havebeen done on this topic outside examinations of animals exposed toradioactive dust from nuclear accidents.To examine the effect of air pollution, the researchers exposed two groupsof mice for 10 weeks - one just one kilometre from two of Hamilton's steelmills, the other 30 kilometres away in a rural area. They fed both groupsthe same diet, gave them bottled water and tended to them in the same way.Essentially, the only difference between the two groups was the air theybreathed.The offspring of the group housed near the steel mills suffered from up totwice as many mutations as offspring from the rural group. Those "steelmill" mice also produced 20 per cent smaller litters. The researchersconclude: "We therefore attribute the effect on inherited mutations in theoffspring of sentinel mice directly to variation in air quality between thesteel and the rural field sites."First gulls, now mice. There's a good chance that air pollution is causingmutations in humans as well. Mice and humans are both mammals and share 99per cent of the same genes. What's bad for them is generally bad for us too.In this case, the damage seems to affect mostly male mice and theiroffspring, but the researchers caution that female mice are likely notimmune.That male mice were especially affected is cause for concern given that theywere only exposed to the polluted air for 10 weeks. Steelworkers tend to bemale and may be exposed to high levels of pollutants for years. Similarly,those living in the immediate vicinity of mills will be exposed for longperiods of time, thereby increasing the chances of genetic damage.Yet the steel industry response to the study was shocking. One industryspokesperson actually told the Canadian Press: "We dismiss this study asspeculative and irresponsible." I guess I shouldn't be surprised. Theresponse is reminiscent of the tobacco industry line when confronted withevidence of the harm caused by smoking. Rather than saying, "Wow, that's adisturbing finding. We'll fund further studies and look at ways to reduceour emissions in the meantime," the industry simply dismisses sound scienceout of hand.Tobacco and steel share another commonality - the chemicals thought to beresponsible for the mutations in the Hamilton mouse study are also found incigarette smoke. They're called polycyclic aromatic hydrocarbons, or PAHs, agroup of about 100 different chemicals that are created largely when fossilfuels are burned, but are also found in charred food and cigarettes. PAHlevels around steel mills in Hamilton are 50 times higher than in ruralareas."There is an urgent need to investigate the genetic consequences associatedwith exposure to chemical pollution through the inhalation of urban andindustrial air," say the Hamilton researchers. Indeed, with the vastmajority of us now living in urban areas and millions of people exposed toair pollution from steel mills, coal-fired power plants and automobiles, wecannot afford to simply accept the industry line of doing nothing -especially when it could be the next generation that suffers the most.********If this email is cut short, changingplanet/messagesYou can help us make a difference. Click here for details:http://changingplanet.supremalex.org/help.htmChanging Planet News - Where Ethics, Science and Spirituality BlendCOLLECTIVE CONSCIOUSNESS PROJECT: If this email sparked emotions in you, positive or negative, please pray, meditate, visualize or concentrate on the best possible outcome for Humanity and Earth for AT LEAST 10 seconds. On the web at http://changingplanet.supremalex.orgNews and service since 1995