Report highlights necessary changes in air quality standards and
regulations
If you are living in the eastern United States, the environment around
you is being harmed by air pollution. From Adirondack forests and
Shenandoah streams to Appalachian wetlands and the Chesapeake Bay, a new
report 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, Threats From Above: Air Pollution Impacts on Ecosystems and
Biological Diversity in the Eastern United States, is the first to analyze
the large-scale effects that four air pollutants are having across a broad
range of habitat types (see inset). The majority of recent studies focus
on one individual pollutant. Over 32 experts contributed to the effort;
the prognosis is not good.
"Everywhere we looked, we found evidence of air pollution harming
natural resources," comments Dr. Gary M. 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."
Pollutants poison areas far from their point of origin
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.
Co-author Dr. Timothy H. Tear, of The Nature Conservancy, comments,
"Deposited pollutants have tangible human impacts. Mercury contamination
results in fish that are unsafe to eat. Acidification kills fish and
strips nutrients from soils. Excess nitrogen pollutes estuaries, to the
detriment of coastal fisheries. And ground-level ozone reduces plant
growth, a threat to forestry and agriculture."
New air quality standards are critical to protecting natural
resources
At the heart of the report is a call to action. Currently, U.S. air
quality standards 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 and resident plants and animals.
"To safeguard ecosystem health, we need a new way of thinking about air
pollution – one that moves beyond measuring what is put up in the air, and
captures actual impacts to natural areas, wildlife, and the services they
provide," Lovett notes.
The authors urge U.S. policymakers to establish 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. By establishing thresholds, pollutants can be regulated in a way
that preserves functioning ecosystems. In some areas, such as Rocky
Mountain National Park, federal agencies have already adopted this
approach to evaluate the threat from air pollution. It is also being used
to regulate air pollution throughout Europe.
Monitoring is an essential tool
Establishing critical loads will require renewed investment in
monitoring programs for air pollution and the ecosystems it affects. "We
can't assess if ecosystems are harmed by air pollution if we don't monitor
them. While some good pollution monitoring programs exist, our current
system is fragmented, underfunded, and has serious gaps," remarks Lovett.
While there may be initial costs to ramping up monitoring efforts,
consider the alternative. The fishless lakes of the Adirondacks are a
harsh reminder that air pollution does not recognize property lines. Tear
concludes, "In the absence of critical loads, there is a false security in
conventional land conservation. We can manage natural areas with the best
possible protocols, but we can't really 'protect' the land if it is
continually exposed to air pollution."
SOURCE: Cary Institute of Ecosystem Studies