Environment & Energy
Related: About this forumEnv. Canada Finds 40% Increase In Birds' Eggs Upstream From Tar Sands Operations
OTTAWA Environment Canada scientists have observed evidence of toxic contamination of wildlife upstream from Alberta's natural bitumen deposits that coincides with the oilsands industry's expansion, Environment Minister Peter Kent was told last summer.
According to internal documents obtained by Postmedia News, the government was urged to investigate recent scientific observations of a 40 per cent increase of mercury in bird eggs, considered to be a key environmental indicator of contamination of the natural ecosystems.
"Environment Canada has already undertaken contaminants monitoring in wildlife and that work is continuing," said an internal document outlining the government's communications plan for the launch of its oilsands monitoring initiative from last July. "We have seen an increased exposure of mercury in bird eggs which is why more research is required to evaluate trends and sources of the contamination."
The advice, released through access to information legislation, followed peer-reviewed research, led by Environment Canada scientist Craig Hebert, that reported a 40 per cent increase of mercury levels in California gull eggs from a Lake Athabasca colony between 1977 and 2009 a period of significant growth for the oilsands industry. Hebert's research said that "contamination from oilsands development (was) one possibility, but other external (mercury) sources must also be considered."
EDIT
http://www.edmontonjournal.com/business/Mercury%20contaminating%20bird%20eggs%20oilsands%20region%20Environment%20Canada/6709356/story.html
Ecotruth
(1 post)Mercury is emitted to the air by human activities, such as manufacturing or burning coal for fuel, and from natural sources, such as volcanoes.
Typically, mercury is released into the atmosphere in one of three forms:
elemental mercury: can travel a range of distances, may remain in the atmosphere up to one year and may travel globally before undergoing transformation
particle-bound mercury: can fall out of the air over a range of distances
oxidized mercury (sometimes called ionic or reactive gaseous mercury (RGM)): found predominantly in water-soluble forms, which may be deposited at a range of distances from sources depending on a variety of factors including topographic and meteorologic conditions downwind of a source.
What happens to mercury after it is emitted depends on several factors:
- the form of mercury emitted
- the location of the emission source
- how high above the landscape the mercury is released (e.g., the height of the stack)
- the surrounding terrain
- the weather.
Depending on these factors, atmospheric mercury can be transported over a range of distances before it is deposited, potentially resulting in deposition on local, regional, continental and/or global scales. Mercury that remains in the air for prolonged periods of time and travels across continents is said to be in the "global cycle."
Recent emissions estimates of annual global mercury emissions from all sources, natural and anthropogenic (human-generated), which are highly uncertain, are about 4800-8300 tons per year.
U.S. anthropogenic mercury emissions are estimated to account for roughly 3 percent of the total global emissions, and the U.S. power sector is estimated to account for about 1 percent the total global emissions. EPA has estimated that about one third of U.S. emissions are deposited within the contiguous U.S. and the remainder enters the global cycle.
Current estimates are that less than half of all mercury deposition within the U.S. comes from U.S. sources, although deposition varies by geographic location. For example, compared to the country as a whole, U.S. sources represent a greater fraction of the total deposition in parts of the Northeast because of the direction of the prevailing winds.
http://www.epa.gov/hg/exposure.htm#1
Nihil
(13,508 posts)Any chance you could change your title please?
"40% Increase In Birds' Eggs Upstream From Tar Sands Operations"
sounds a hell of a lot nicer than
"40 per cent increase of mercury in bird eggs (Upstream From Tar Sands Operations)"
Thought I was going to read a positive post for a change ...