Mercury
Mercury is a potent neurotoxin, particularly
damaging to the developing fetus and young child. Eight percent of the
women of childbearing age have levels of mercury in their blood that
exceeds the level EPA considers safe. In addition, there is growing
evidence that exposure to mercury can have adverse cardiovascular effects
for adults, resulting in elevated blood pressure and incidence of heart
attack (U.S. EPA, http://www.epa.gov/mercury/information1.htm).
Eating mercury-contaminated fish and shellfish is the primary route
of exposure for most people. All the Northeast states, including Maine,
have issued fish consumption advisories for mercury—but dietary
habits are not easily changed. And humans are not the only ones at risk;
mercury also threatens fish-eating birds and mammals at the top of the
food chain, including species that have long stood as environmental
icons such as loons and eagles.
Sources of mercury pollution include discharges of dental mercury into
wastewater systems or even spills at workplaces or schools. But most
of the mercury responsible for poisoning waterbodies—and the fish
within them—is deposited from the atmosphere. Roughly two-thirds
of all mercury deposited in the United States comes from domestic sources
with the nation’s coal-fired power plants and commercial/industrial
boilers as the largest sources.
A study conducted by a consortium of New England air, water and waste
agencies in 1998 found that nearly a third of the mercury deposited
in the Northeast came from U.S. sources outside the region. The study
also showed that power plants located outside the region contributed
more to mercury deposition in the Northeast than plants within the region
(NESCAUM, NEWMOA, and NEIWPCC, 1998).
In its report to the Legislature in January 1998, the Land & Water
Resources Council outlined the following Mercury Reduction
Strategy for Maine:
- Reduce air emissions and discharges from Maine's largest sources;
- Divert mercury from the solid waste stream;
- Complete a Maine inventory & risk ranking;
- Expand fish sampling;
- Continue remediation activities at mercury contaminated sites;
- Develop regional & national strategies to reduce mercury emissions;
- Urge federal agencies to adopt one health based standard for mercury
in fish;
- Focus biological research on effects of mercury on wildlife; and
- Access & implement strategies to communicate fish consumption
advisories.
This multi-disciplinary approach has signficantly reduced mercury emissions.
In Maine, overall mercury emissions to the air have dropped by more
than 75% from their peak in 1991, with reductions by municipal waste
incinerators leading the way.
Regionally, implementation of the 1998 New England Governors
and Eastern Canadian Premiers Mercury Action Plan has
led to a drop in regional mercury emissions of more than 55 percent.
As in Maine, this is primarily due to controls on municipal waste
combustors and medical waste incinerators, which have achieved
90-95 percent reductions. Ongoing efforts to reduce the use of
mercury in products, remove mercury from schools, and eliminate
mercury releases from dental offices are providing further reductions.
The Maine DEP has publised the following information about mercury deposition
from air.
Document Title and Description |
Microsoft Word or Excel
Format |
Adobe Acrobat PDF |
Mercury Deposition in Maine: Status Report
2003, by Douglas Saball, Jeff Emery, Ellen Parr-Doering,
Andy Johnson and David Wright (July 2003) Summary of mercury
deposition in Maine from air pollution. |
Word
(18 Mb) |
PDF
(1.1 Mb) |
For more information on mercury reductions in other media (water and
waste), visit Maine DEP's Mercury page.
Useful Links
- Mercury Information Page - U.S. EPA (http://www.epa.gov/mercury/index.html) The
Environmental Protection Agency is working to reduce the amount of
mercury in the environment. This is the first stop for information
from controlling power plant emissions to proper disposal of your
home fever thermometer.
- Northeast States for Coordinated Air Use Management (NESCAUM) Mercury
links - (http://www.nescaum.org/topics/mercury-inventory) Find
out what the Northeast States are doing about reducing air emissions
of mercury.
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