Conversion of inorganic mercury to monomethylmercury accounts for around half of this neurotoxin that is present in polar marine waters, reports a study published online this week in Nature Geoscience. Monomethylmercury accumulates in marine organisms, with serious implications for human health.
Igor Lehnherr and colleagues incubated seawater samples, collected from the Canadian Arctic Archipelago, with isotopically labelled inorganic mercury. The inorganic mercury was converted, through methlylation, into monomethylmercury in all samples. They estimate that methlylation of inorganic mercury accounts for around 47% of the monomethylmercury present in these waters, and could account for a signification fraction of the mercury found in Arctic marine organisms.