A new report released Monday by the Cary Institute of Ecosystem Studies and The Nature Conservancy has found that air pollution is degrading every major ecosystem type in the northeastern and mid-Atlantic United States.

The report is the first to analyze the large-scale effects that four air pollutants are having across a broad range of habitat types. However, the majority of recent studies focus on one individual pollutant.

"Everywhere we looked, we found evidence of air pollution harming natural resources," said Gary Lovett, an ecologist at the Cary Institute and the lead author of the report. "Decisive action is needed if we plan on preserving functioning ecosystems for future generations."

The pollutants assessed – sulfur, nitrogen, mercury, and ground-level ozone – largely originate from smokestacks, tailpipes, and agricultural operations. While initially airborne, these pollutants eventually return to the landscape, where they contaminate the soil and water.

Airborne emissions can travel long distances before making their way back to the ground. Because the eastern United States is downwind from large industrial and urban pollution sources, it receives the highest levels of deposited air pollution in North America. This is bad news for vulnerable wildlife, forest productivity, soil health, water resources, and ultimately, economies.

The authors urge US policymakers to establish new air quality standards that are based on critical loads. This is defined as the maximum level of deposited pollution that ecosystems can tolerate before harmful effects occur.

(Xinhua News Agency July 22, 2008)