New map pins down air pollution

Every day the average person breathes in over 2,000 gallons of air. With every breath, the lungs draw in millions of microscopic particles from the air. This particulate matter travels deep into the lungs, dodging the hair-like cilia in the respiratory tract, and triggers conditions like asthma, bronchitis and cardiovascular disease. Even healthy people can find themselves short of breath. Researchers aim to map out exactly how particulate matter spreads across the globe and how much it affects human health.

Canadian researchers have made this task easier by publishing the first long-term global map, which blended aerosol measurements from two NASA satellites with vertical measurements from a computer model. The new map will allow researchers to look at less studied parts of the world, like Asia's growing cities, and determine how PM2.5 affects people over a longer period of time. Particles exist everywhere in Earth's atmosphere, but urban areas usually host the smaller, human-generated PM2.5 particles. Activities like farming, construction and traffic form PM2.5 in fine dust and soot, which can then travel on the wind or remain suspended in the air for weeks at a time.

The abundance of PM2.5 has been hard to measure in both developed and undeveloped countries due to a lack of air pollution sensors and errors caused by clouds and bright land surfaces, which blur the line between particles in the upper atmosphere and the particles in the lower atmosphere that actually affect people. The new map shows average PM2.5 results over a period of five years, from 2001 to 2006. It also gives the first look at PM2.5 data in developing countries.

According to the map, more than half of Asia's population is breathing air deemed unacceptable by the World Health Organization's air quality standards. PM2.5 particles are about one-tenth the width of a human hair and are so small they can slip into the bloodstream. Nearly 60,000 deaths each year can be attributed to diseases sparked by air pollution, according to the American Heart Association. In the United States, the Midwest and East have the highest levels of PM2.5, but overall the United States has a lower amount of air pollution than developing countries.

According the Environmental Protection Agency, PM2.5 doesn't just endanger human health. It also disrupts ecosystems, reduces visibility, depletes nutrients from the soil, turns lakes acidic and erodes stone monuments. You can track your own state's levels of air pollution at the EPA website. To further reduce air pollution, you can help by driving less, using hand-powered landscaping equipment instead of gas-powered, refueling in the evening to reduce ground-leve ozone, avoiding oil-based paints and solvents and, of course, reducing, reusing and recycling.