More forms of mercury can be converted to deadly methylmercury than previously thought, according to a study published Sunday in Nature Geoscience. The discovery provides scientists with another piece of the mercury puzzle, bringing them one step closer to understanding the challenges associated with mercury cleanup.
Earlier this year, a multidisciplinary team of researchers at Oak Ridge National Laboratory discovered two key genes that are essential for microbes to convert oxidized mercury to methylmercury, a neurotoxin that can penetrate skin and at high doses affect brain and muscle tissue, causing paralysis and brain damage.
The discovery of how methylmercury is formed answered a question that had stumped scientists for decades, and the findings published this week build on that breakthrough.
Most mercury researchers have believed that microbes could not convert elemental mercury—which is volatile and relatively inert—into methylmercury. Instead of becoming more toxic, they reasoned that elemental mercury would bubble out of water and dissipate. That offered a solution for oxidized mercury, which dissolves in water. By converting oxidized mercury into elemental mercury, they hoped to eliminate the threat of methylmercury contamination in water systems.
ORNL’s study and a parallel study reported by Rutgers University, however, suggest that elemental mercury is also susceptible to bacterial manipulation, a finding that makes environmental cleanup more challenging.
Read more at: Phys.org