Threats From Above: Air Pollution Impacts on Ecosystems and Biological Diversity in the Eastern United States

Nature Conservancy / by Gary Lovett and Tim Tear
http://www.ecostudies.org/Threats_from_Above.pdf

[Press release] This report assessed the impacts of four major pollutants on six ecosystem types in areas that receive some of the nation’s highest levels of atmospheric deposition (air pollution deposited to the landscape). These areas are often located downwind from large power plant, industrial and urban pollution sources. Among the concerns:

• Ground-level ozone reduces plants’ ability to harness sunlight for growth harming both natural ecosystems and agricultural crops.
• High levels of deposited mercury have negative impacts on wildlife – from salamanders in the Appalachian Mountains to loons in the Adirondacks and bald eagles in Maine.
• Acid rain is making sensitive lakes and streams uninhabitable by fish in the mountains of the Northeast and the Southern Appalachians.
• Excess nitrogen – in part from air pollution – is harming waterways from Rhode Island’s Narragansett Bay to Long Island Sound to Chesapeake Bay. Nitrogen also decreases the disease resistance of trees, leaving them more vulnerable to pests and pathogens.

Important background information from other studies on each of the pollutants includes:

• Ground level ozone has been estimated to cause $3-6 billion in reduced crop production annually.
• Current levels of mercury deposition are 4 to 6 times higher than in 1900. In one study, over 15,000 fish were sampled, and 10 of 13 recreational fish species had average mercury concentrations in the fillet that exceeded the EPA levels set to protect human health.
• More than 40 percent of the lakes in the Adirondacks of New York are chronically acidic or sensitive to episodic acidification.
• People are responsible for doubling the rate of nitrogen entering the active nitrogen cycle over the last half century.

Air quality standards in the United States are determined by direct impacts to human health, with regulations targeting emission levels – what leaves tail pipes and smoke stacks. They do not take into account where airborne pollution is actually deposited in the landscape or how this pollution compromises our soil and water resources, natural habitats or the species that live in them. (Docuticker)