Study: Air pollution a grave danger

Think twice before driving when walking is an option — and the environment will thank you in more ways than one.

According to a new report by the Nature Conservancy and the Cary Institute of Ecosystem Studies, the Earth’s ecosystems are in grave danger. The problem? Air pollution caused by emissions from smokestacks, agricultural activities and tailpipes. Thirty-two experts studied four pollutants in the eastern United States — ground-level ozone, nitrogen, sulfur and mercury — and discovered they cause far-reaching harm to wildlife, rivers, forests and humans.

“One of the things that we’re trying to get people to think about is that air pollution is not a problem with cities only but that it happens anyplace,” said Judy Dunscomb, a contributor to the report who works in the Nature Conservancy’s Charlottesville branch.

Researchers found that nitrogen in the air leads to acidic deposits in rivers and soils. High levels of acidity in soil lead to a decrease in nutrients.

As for bodies of water, air pollution is having an effect locally, according to Dunscomb. She said that many rivers and streams in Shenandoah National Park have become far too acidic to support life and have lost large numbers of wildlife, from trout to insects.

The harmful effects of air pollution are even affecting the economy, according to Tim Tear, a co-author of the report. The decrease of nutrients in soil reduces the disease resistance of trees, which, in turn, reduces the growth rates of forests by as much as 10 percent, hurting the timber industry, Tear said. Ground-level ozone also impedes plants’ growth, reducing crop production.

Researchers underscored the dangers posed by high levels of mercury, which cause behavioral and neurological changes in land and water animals. While mercury may not kill the fish in a stream, it can potentially sicken humans who eat the fish.

The report includes a “call to action” that urges the United States to crack down on air pollution by enacting regulations based on the maximum level of pollutants that ecosystems can handle, known as “critical loads.” More important than the amount of pollutants is how the pollutants are deposited, as they can travel hundred of miles in the air, the report states.

According to Tear, such an approach has been used by the European Union for the last 10 years. Rocky Mountain National Park is one of the few areas in the United States with an established critical load.

“Critical loads is a concept that the [Environmental Protection Agency] is beginning to look at much more closely,” Tear said. “What we are hoping to do is elevate the importance of that approach. Congress needs to provide the EPA the authority to develop the critical loads approach.”

The approach will not succeed, however, without more monitoring of pollutant deposits, according to the report. U.S. air quality regulations focus only on direct effects on health.

“There are many other impacts that have direct and indirect impacts on society through the ecosystem,” Tear said. “We need to pay much closer attention to what’s going on in our natural world.”