Sea water turns inorganic mercury toxic

EDMONTON, Alberta, April 27 (UPI) -- Canadian researchers say they've confirmed a relatively harmless inorganic form of mercury becomes a potent neurotoxin when released into the world's oceans.

A study led by University of Alberta scientists tested water samples in the Arctic Ocean and found that inorganic mercury, released from human activities such as industry and coal burning, undergoes a process called methylation in seawater and becomes toxic monomethylmercury.

Monomethylmercury, unlike inorganic mercury, is bio-accumulative, meaning its toxic effects increase as it moves through the food chain from small sea creatures to humans, a university release said Wednesday.

The methylation process occurs in oceans all over the world, the researchers said, and is thought to be initiated by microbial life forms.

Biological sciences researcher Igor Lehnherr said the process could account for a significant amount of the mercury found in Arctic marine organisms.

The research was published in the journal Nature Geoscience.