Do you ever watch a jogger running alongside a busy highway and wonder whether the deep inhalation of exhaust fumes is really all that wise? Some things just run contrary to good sense—how can a person be seeking health and subjecting themselves to counter-health at the same time? It’s a mystery to me.
Automobile exhaust spews hydrocarbons and nitrogen oxides (which react to form ground-level ozone), carbon monoxide (robs the brain of oxygen), and other health hazards—sulfur dioxide, benzene, formaldehyde, and lead. Perhaps even more important to those who live, work, or play alongside busy highways, though, is the respiratory threat of tiny substances known as particulate matter or “PM.”
Tiny assassins in the air
Of special concern are particles measuring 2.5 µm or less in diameter (designated PM 2.5). At 1/30th the width of a human hair, these substances are able to escape normal filtering mechanisms and pass directly to the most sensitive areas of the lungs, potentially causing serious health problems. It may be there are more deaths caused by automobile pollution than by automobile accidents.
Children and the elderly are especially vulnerable. Numerous studies have shown a direct relationship between how close children live in a high-traffic area and ailments like asthma, reduced lung function, and even cancer. California researchers found PM 2.5 concentration to be 25 times greater near interstate highways—and it didn’t drop to normal levels until they reached a distance of about 990 feet downwind.
Prevention and assessment
What can you do to protect yourself and your loved ones from the dangers attributed to PM 2.5 concentrations? Here are some tips to help you assess and respond to the threat.
- Know the danger. The Air Now website (www.airnow.gov) provides the current level of PM 2.5 (and other pollutants) in the United States and Canada, allowing you to take advantage of the good air days and enact preventative measures on unhealthy days.
- Avoid exposure to areas of heavy traffic as much as possible. It may be difficult to move your residence further from a highway, but do all you can to limit your intake of PM 2.5.
- Get sufficient vitamins and minerals—especially antioxidants. This helps defend your body from the harmful effects of particulate matter in the atmosphere.
Of the three primary physical essentials—air, food, and water—air is the most critical. Take measures to protect your lungs against pollution. You don’t have to jog by the four-lane: choose off-highway settings or exercise indoors.
You care about what you eat—now begin thinking carefully about what you breathe.