Air Pollution…forgotten but not gone

Air Pollution…Forgotten but not gone

An article entitled “Small things make a big difference” in Sports Medicine opens with an alarming statistic about air pollution by the World Health Organization:  some two million people die prematurely each year due to air pollution.  Although the article focuses on athletes participating in sports involving deep breathing, it’s relevant to all who are exposed to air pollution; that would be almost all people (Sports Med 2012:  42 (12)).

In the 1960s and 1970s air pollution got our attention and rightfully so.  Activists took on big companies that were discharging wastes on a regular basis.  Cars had emission controls added and laws were passed to help clear the air.  The article about athletes referenced the air pollution in cities where recent Olympic competitions have been held.  Although compared to cities like Beijing, we seem to be doing fine, were not.  (Sports Med 2012:  42 (12)).

Even though the air looks clear, it isn’t necessarily so.  We may find comfort in the fact that smog is a rarity, and that except for an occasional blocked chimney or the burning of green wood, the air seems pretty clear.

A major source of air pollution is cars and truck exhaust.  When fossil fuels are burned, hydrocarbons and nitrogen dioxide are produced.  Sunlight changes hydrocarbons in car exhaust into ozone.  This latter chemical is very irritating to the respiratory tract, and is an oxidant.  Ozone is also the main constituent of smog.  Even brief ozone exposures can irritate the respiratory tract.  Asthma is more common in children that are frequently exposed to it.  Summer, late morning and early afternoon are times ozone levels are usually the highest.

Another component of air pollution is particulate matter – small particles suspended in air.  It too comes from the fossil fuel combustion, particularly diesel.  Such particles cause local and systemic inflammation.  Inflammation is a non-specific process that makes blood vessels leak fluid and cells into an area.  If it’s

 

 

chronic, it damages tissue and furthers the development of diseases such as arteriosclerosis and COPD.  Regular exposure to air pollutants makes asthma, lung cancer, breast cancer and other chronic diseases more likely to develop.

It’s ironic that exercise, which should help prevent many chronic diseases, when done outdoors near heavy traffic, can make them more likely to develop.  How can that exposure be decreased?   Avoid exercising during the times with the highest ozone levels – from mid-morning to mid-afternoon.  Also try to avoid exercising outside on days with no wind, or at least avoid the areas with significant traffic when there’s little wind.  Try not to exercise on or near busy roads, especially in areas where a lot of vehicles are idling as the pollutants will be more concentrated there.  Wind is actually a good thing when it comes to air pollution because it disperses the pollutants.  Cigarette smoke is harmful to all involved, even those just emptying ash trays.

Vitamin C has anti-oxidant properties that help the body neutralize damaging free radicals; it also decreases histamine production.  Smoke from wood burning is also something to avoid.  If you’re careful, air pollution exposure can be decreased, and that is worth a few extra precautions.

 

Sources:  The Merck Manual, “Fresh Air that isn’t” by Katherine Bowers in Women’s Health March 2011 and the above article noted above “Small things make a big difference” in Sports Med 2012:  42(12)

 

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