Methylmercury Found in Antarctic Sea Ice

The atmospheric dumping of the mercury occurs all year but is most evident during the Antarctic spring when the most sea ice melts and releases the toxicant.

A toxic form of mercury in Antarctic’s atmosphere and sea ice was discovered by Australian scientists.

The study, led by a team from the University of Melbourne, found significant amounts of methylmercury, an especially dangerous strain of mercury, in the Southern Ocean.

Mercury in Seafood Does Not Appear To Increase the Risk of Dementia: Study
Those who ate more seafood had higher levels of mercury in the brain, but the autopsies showed no signs of brain disease in those who had mercury in the brain.

‘Toxic mercury enters the bloodstream and reaches the brain, leading to developmental problems in the fetus, infants, and children.’

Caitlin Gionfriddo, a PhD student at the University of Melbourne who worked on the project, said the study revealed that methylmercury released by Antarctic ice into the ocean could be contaminating the food chain.

"There are high levels of methylmercury in our ecosystems, especially in the marine environment, but we don't know how it's being produced," said Gionfriddo.

"We see it accumulate in the food web and most of it likely comes from atmospheric deposition of mercury onto sea water. "

Inorganic Mercury Exposure Causes More Damaged Cell Processes Than Organic Mercury
Inorganic mercury, which was previously thought to be a less harmful form of the toxic metal, is very damaging to key cell processes.

The research, published in the journal Nature Microbiology, said the atmospheric dumping of the mercury occurs all year but is most evident during the Antarctic spring when the most sea ice melts and releases the toxicant.

Researchers associated with the project expressed concerns that as global warming continues humans will be subject to greater exposure to mercury by consuming fish from the region.

Higher Blood Mercury Level may Increase Glaucoma Risk: University of California
Lower blood manganese levels and higher blood mercury levels are associated with greater glaucoma prevalence, affecting many organ systems, including eye.

Methylmercury can travel easily from the stomach to the bloodstream when ingested by humans, eventually reaching the brain and potentially causing developmental problems in fetuses, infants, and children.

John Moreau, lead author of the study, said it is still unknown why the bacteria in methylmercury can cause developmental problems.

Arsenic, Mercury and Selenium in Bighead and Silver Carp Not a Health Concern
The concentrations of selenium, mercury and arsenic in silver carp and bighead from the lower Illinois river may not be a health concern for the consumers, a new study found

"After half a century of research, we still don't know why. Most people think it's just an accidental side reaction; some people think it's a reaction to toxicity," Moreau said.

The next step in the research is to study what environmental factors are creating the methylmercury and the extent of the contamination in Antarctic waters.

Source-IANS