Air pollution may alter genes

[Susan L Gawarecki <loc@icx.net>]

I thought this opinion piece might interest RadSafers.  The story

references "examinations of animals exposed to radioactive dust from

nuclear accidents" (2nd paragraph).  Does this refer to studies at

Chernobyl?  What were the results and how do they compare to what is

reported below?



--Susan Gawarecki



Air pollution may alter genes

By David Suzuki

Tuesday, January 07, 2003

http://enn.com/news/enn-stories/2003/01/01072003/s_49194.asp



Six years ago, scientists found that herring gulls living near steel

mills

around the harbour in Hamilton, Ontario, tended to have high DNA

mutation rates. These mutations were then transferred to the next

generation of gulls, increasing the offspring's chances of developing

genetic diseases like cancer and birth defects. Researchers suspected at

the time that air pollution was causing the mutations, but they couldn't

eliminate other factors, such as polluted water or contaminated fish,

that also could have been responsible. 



Now other scientists have published a paper indicating that air

pollution

is indeed the likely culprit behind the mutations. What's more, there's

no reason why human DNA should be immune from the same pollution.

So our genes may also be damaged and inherited by our children. It's

sobering to think that chemicals in our air affect us at a genetic

level.

Few studies have been done on this topic outside examinations of

animals exposed to radioactive dust from nuclear accidents. 



To examine the effect of air pollution, the researchers exposed two

groups of mice for 10 weeks — one just one kilometer (.62 miles) from

two of Hamilton's steel mills, the other 30 kilometers (18.6 miles) away

in a rural area. They fed both groups the 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 they breathed. 



The offspring of the group housed near the steel mills suffered from up

to twice as many mutations as offspring from the rural group. Those

"steel mill" mice also produced 20 percent smaller litters. The

researchers conclude: "We therefore attribute the effect on inherited

mutations in the offspring of sentinel mice directly to variation in air

quality between the steel and the rural field sites." 



First gulls, now mice. There's a good chance that air pollution is

causing

mutations in humans as well. Mice and humans are both mammals and

share 99 percent 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 their offspring, but the researchers caution that female mice

are likely not immune. 



That male mice were especially affected is cause for concern, given that

they were only exposed to the polluted air for 10 weeks. Steelworkers

tend to be male and may be exposed to high levels of pollutants for

years. Similarly, those living in the immediate vicinity of mills will

be

exposed for long periods of time, thereby increasing the chances of

genetic damage. 



Yet the steel industry response to the study was shocking. One industry

spokesperson actually told the Canadian Press: "We dismiss this study

as speculative and irresponsible." I guess I shouldn't be surprised. The

response is reminiscent of the tobacco industry line when confronted

with evidence of the harm caused by smoking. Rather than saying,

"Wow, that's a disturbing finding. We'll fund further studies and look

at

ways to reduce our emissions in the meantime," industry simply

dismisses sound science out of hand. 



Tobacco and steel share another commonality: the chemicals thought to

be responsible for the mutations in the Hamilton mouse study are also

found in cigarette smoke. They're called polycyclic aromatic

hydrocarbons, or PAHs, a group of about 100 different chemicals that

are created largely when fossil fuels are burned, but are also found in

charred food and cigarettes. PAH levels around steel mills in Hamilton

are 50 times higher than in rural areas. 



"There is an urgent need to investigate the genetic consequences

associated with exposure to chemical pollution through the inhalation of

urban and industrial air," the Hamilton researchers say. Indeed, with

the vast majority of us now living in urban areas and millions of people

exposed to air pollution from steel mills, coal-fired power plants and

automobiles, we cannot afford to simply accept the industry line of

doing nothing — especially when it could be the next generation that

suffers the most.



-- 

.....................................................

Susan L. Gawarecki, Ph.D., Executive Director

Oak Ridge Reservation Local Oversight Committee

102 Robertsville Road, Suite B, Oak Ridge, TN 37830

Toll free 888-770-3073 ~ www.local-oversight.org

.....................................................

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