Mercury converted to its most toxic form in ocean waters

[OKIsItJustMe]

http://www.expressnews.ualberta.ca/en/NewsArticles/2011/04/Mercuryconvertedtoitsmosttoxicforminoceanwaters.aspx

Mercury converted to its most toxic form in ocean waters

By Brian Murphy April 27, 2011

(Edmonton) University of Alberta-led research has confirmed that a relatively harmless inorganic form of mercury found worldwide in ocean water is transformed into a potent neurotoxin in the seawater.

After two years of testing water samples across the Arctic Ocean, the researchers found that relatively harmless inorganic mercury, released by human activities like industry and coal burning, undergoes a process called methylation and becomes deadly monomethylmercury. Methylation, in this case, is the addition of a methyl group to heavy metals catalyzed by certain enzymes.

Lead U of A researcher Igor Lehnherr says the greatest exposure to monomethylmercury for humans is through the consumption of marine-based foods. “Unlike inorganic mercury, monomethylmercury both bio-accumulates and bio-magnifies, meaning its toxic effects are amplified as it progresses through the food chain,” said Lehnherr. “Humans are at the top of the food chain, so we’re getting the highest content of this neurotoxin through contaminated seafood.”

Lehnherr, who just last week was awarded his PhD in biological sciences, says the data collected in the Arctic Ocean paints a disturbing picture. “The conversion of inorganic mercury to monomethyl mercury accounts for approximately 50 per cent of this neurotoxin present in polar marine waters,” said Lehnherr. “Those high levels could also account for a significant amount of the mercury found in Arctic marine organisms.”

…

http://dx.doi.org/10.1038/ngeo1134

[kristopher]

1. This was in doubt?

http://www.einap.org/envdis/Minamata.html

http://www.hgtech.com/Information/Minamata_Japan.html


And http://www.nippon-foundation.or.jp/eng/ReadJapan/Non_fiction_030.html
Non Fiction

The Terrible Science behind Minamata Disease
(Minamata byo no kagaku)
Nishimura Hajime and Okamoto Tatsuaki
349 pages, Nippon Hyoronsha, 2001

Minamata disease—a severe neurological disorder caused by mercury poisoning—was perhaps the farthest-reaching, most pernicious environmental disaster of the twentieth century. The Chisso Corporation, located in the city of Minamata in Kumamoto Prefecture, had been discharging methyl mercury, a byproduct of the manufacture of acetaldehyde, into the Minamata Bay for twenty years, when horrifying neurological symptoms began to show up in the Minamata population. Citizens, even as new generations continued to suffer, waged a long, agonizing public battle to seek relief from the government and the company. Many years after the fact, scientific research established the link between mercury poisoning and what today is known to as Chisso-Minamata disease, and only then did the government and the company accept responsibility.
Nishimura Hajime, a scientist who researches environmental pollution, and Okamoto Tatsuaki, the labor chief who fought Chisso alongside the victims of Minamata disease, here take a look at the science behind the disease. They examine the chemical processes involved, the catalysts used in production, and the measures taken—and not taken—to prevent poisoning. In this tragic tale, there are lessons about science and technology for us all.

[OKIsItJustMe]

2. “first direct evidence”

…

The researchers say this is the first direct evidence that inorganic mercury is methylated in seawater. The research team is now going to look at how the process works.

…

[kristopher]

3. It is great to focus attention on this process...

but I still don't see anything new here. I only read the abstract and it isn't stated clearly there whether the mechanism was identified. Was their water sample abiotic? If they've identified a strictly chemical process that occurs without a contribution by biological agents, that would be new; but I don't see that in the abstract.

In any case, thanks for the post. The more people understand this the better.

[ElsewheresDaughter]

4. my heart goes out to the poor Inuit people most

[txlibdem]

5. You mean like the 50 tons of Mercury that coal plants in the US spew out each year

--------------------------------------------
EPA officials
estimated that about 50 tons of elemental
mercury are emitted each year from U.S.
coal-burning powerplants, with lesser
amounts coming from oil- and gas-burn-
ing units.
-------------------------------------------

Links:
http://www.epa.gov/ttnatw01/utility/hgwhitepaperfinal.pdf
http://www.in.gov/dnr/reclamation/files/Ridgeway_ISMR.pps
http://pubs.usgs.gov/fs/fs095-01/fs095-01.pdf

And yet, as usual, not a peep out of the so-called "environmentalists" on DU.