We don't appear to have a legacy of mercury toxicity in those with only
occasional exposure.
Interestingly, the following source lists emissions by activity source
to the air, land and water of mercury in Australia. The annual 25,000
kg total is spread across 75 categories.
Landfill is No. 74 (with 0.0074kg p.a.)
The top source is paved and unpaved roads (I assume the unpaved was
included for simplicity) with 8800kg
Electricity generation (No5) is 1207.912Kg and when you throw in
number 12 (coal mining) 160kg it does put the matter into some
perspective.
http://www.npi.gov.au/cgi-bin/npireport.pl?proc=substance;substance=53#Details
One might compare the situation with that of coal plants in the US:
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Older coal plants: highly polluting
Fine particles: The fleet of existing coal plants produces large
quanitities of fine particles, also known as PM2.5, formed from soot,
sulfur dioxide, nitrogen oxides, and metals. These fine particles are
estimated to result in 24,000 premature deaths in the United States,
averaging 14 lost life-years per person.[4]
Sulfur dioxide: Because most existing coal plants pre-date current air
pollution laws, current plants emit about 13 million tons per year of
sulfur dioxide, approximately a 40% reduction from 1990 levels.[5]
Mercury: Coal-fired power plants are the largest source of mercury in
the United States, accounting for about 41 percent (48 tons in 1999)
of industrial releases.[6][7] According to the Centers for Disease
Control and Prevention, eight percent of American women of
childbearing age had unsafe levels of mercury in their blood, putting
approximately 322,000 newborns at risk of neurological deficits.[7]
Mercury exposure also can lead to increase cardiovascular risk in
adults.[7]
http://www.sourcewatch.org/index.php?title=Clean_coal
As we are discussing the relative utility of CFls, bearing in mind
they reduce not only mercury emissions but other emissions associated
with operation of coal plants this source may be germane:
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Photochemical oxidation of sulphur and nitrous oxides forms nitric,
sulphurous, sulphuric and nitric acids in the atmosphere and these are
deposited as acid rain downwind to the coal combustion In addition,
particulates with high acidity are deposited and this is called dry
deposition The entire process is therefore called “acid deposition”.
The smelting of metal ores also releases sulphur dioxide but coal
burning remains the predominant source. To place acid deposition in
context, 200 million tons of Sulphur dioxide is released into the
atmosphere each year or more than 20 times the natural emissions from
volcanoes and biological activity.
It is recognised that the damage caused by acid deposition is both
near to the power station and for hundreds of kilometres. The
industrialised Mid-West of the USA is responsible for acid deposition
in the North-East, Britain pollutes Sweden and acid from China is now
found in Western USA. Acid deposition is responsible for two forms of
environmental damage. Firstly, damage to forests and their ecosystems.
Tree leaves and needles are damaged leading to the death of the tree,
and the soil is leached of nutrients. Freshwater fish habitat is
damaged and many lakes and waterways become ‘dead’. The damage lasts
for decades and perhaps permanently in some cases. This becomes an
environmental heath issue because of damage to natural resources,
productive land and fisheries which will become increasingly important
is a world of increasing population living with a shrinking resource
of productive land.
Developed countries also suffer from air pollution from fossil fuel
and in the USA. 23,000 deaths each year are attributed to pollution
from power plants as well as 500,000 asthma attacks, 16,000 cases of
chronic bronchitis and 38,000 non-fatal heart attacks. The practice of
“clean coal” technology will reduce the release of sulphur dioxide and
other pollutants by an amount dependent on the impurities in the coal.
While China has been indicted for its environmental destruction, the
Bush administration has displayed little resolve to put its house in
order In an initiative of Orwellian dimensions called “Clear Skies”,
coal burning power stations have been permitted to increase sulphur
and nitrous oxide emissions to above levels permitted by the USA Clean
Air Act
www.dea.org.au/docs/DEA_e_p_App1CoalandGas.pdf
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Fran