Dust Gets in Your Eyes…and in Your Lungs. In contrast to invisible pollutants in the air – like ozone, nitrogen dioxide, sulfur and dioxide – we are used to seeing dust in the air. In fact, we are so accustomed to seeing dust or haze (smog) that we seldom think about it. However, there is an invisible danger in “dust,” better called “particulate matter.”
The danger is from very small particles of soot and sulfate crystals – so small that they are invisible. How small? Smaller than 2.5 microns (millionth of a meter), or roughly one fiftieth the thickness of a human hair. Such particles largely come from coal-fired power plants and exhaust of diesel buses, trucks and tractors.
Why are these particles dangerous? Because they can reach the deepest recesses (the alveoli) of the lungs, where oxygen and carbon dioxide exchanges occur. There are reports that some of these particles can pass through the very thin walls of the alveoli and into the blood stream – certainly not a good thing! In addition, the particles of carbon (soot) from diesel exhaust are usually coated with a complex chemical substance called polyaromatic hydrocarbons (PAHs), which are known carcinogens. Not good!
The hazards have been quantified. Scientific American (September 2011) quotes data for U.S. Health Burden Caused by Particulate Pollution from Fossil-Fueled Power Plants (Number of cases per year).
- 4,040 pneumonia
- 9,720 cardiovascular ills
- 30,100 premature deaths
- 59,600 acute bronchitis
- 603,000asthman attacks
- 5,130,000 lost workdays
Can you do anything to protect yourself and family from such invisible dust? Not really, not as long as you drive along metropolitan roads/freeways, or live downwind from coal-fired power plants, or live in an agricultural area with stagnant air (such as the central valley of California). What you and every one of us can do, and should do, is urge your U.S. representatives to support stronger regulation of air pollution by the EPA. We can each do our small part to have healthier air.