Mercury converted to its most toxic form in ocean waters: study

Apr 27, 2011

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 itself.

After two years of testing water samples across the Arctic Ocean, the researchers found that relatively harmless inorganic mercury, released from human activities like industry and coal burning, undergoes a process called methylation and becomes deadly monomethylmercury.

Unlike inorganic mercury, monomethylmercury is bio-accumulative, meaning its toxic effects are amplified as it progresses through the from small sea creatures to humans. The greatest exposure for humans to monomethylmercury is through seafood. The researchers believe the methylation process happens in oceans all over the world and that the conversion is carried out by microbial life forms in the .

The research team, led by recent U of A biological sciences PhD graduate Igor Lehnherr, incubated seawater samples collected from the Canadian Arctic Archipelago. Lehnherr says conversion of inorganic mercury to monomethylmercury accounts for approximately 50 per cent of this neurotoxin present in polar marine waters and could account for a significant amount of the mercury found in Arctic . The researchers say this is the first direct evidence that inorganic is methylated in seawater.

The research was published earlier this month online in Nature Geoscience.

Explore further: Wave energy impact on harbour operations investigated

Related Stories

Bacterial genome may hold answers to mercury mystery

Apr 08, 2011

A newly sequenced bacterial genome from a team led by the Department of Energy's Oak Ridge National Laboratory could contain clues as to how microorganisms produce a highly toxic form of mercury.

Why mercury is more dangerous in oceans

Jun 27, 2010

Even though freshwater concentrations of mercury are far greater than those found in seawater, it's the saltwater fish like tuna, mackerel and shark that end up posing a more serious health threat to humans ...

Arctic home to mysterious mercury deposits

Feb 01, 2011

More mercury is deposited in the Arctic than anywhere else on the planet. Norwegian NTNU researchers think one explanation for this may lie in the meteorological conditions in the Arctic spring and summer.

Recommended for you

NASA sees zombie Tropical Depression Genevieve reborn

9 hours ago

Infrared imagery from NASA's Aqua satellite helped confirm that the remnant low pressure area of former Tropical Storm Genevieve has become a Zombie storm, and has been reborn as a tropical depression on ...

Wave energy impact on harbour operations investigated

13 hours ago

Infragravity period oscillations—waves that occur between 25 and 300 seconds with a wavelength between 100m and 10km—can have an impact on berthing operations, depending on a harbour's geometry.

User comments : 1

Adjust slider to filter visible comments by rank

Display comments: newest first

Vendicar_Decarian
3.7 / 5 (3) Apr 28, 2011
These oceans are causing no end of problems. I am afraid we will have to rid ourselves of them.