Science Café

Our March topic is Mercury cycling at the Earth’s surface: Working to distinguish between natural and anthropogenic sources. Mercury (Hg) is a globally distributed toxic metal that is ubiquitous in the environment. Atmospheric mercury that is deposited to terrestrial and aquatic ecosystems can be converted to methylmercury, which is a potent neurotoxin that is bioaccumulated in food webs. Importantly, anthropogenic activities have increased the amount of mercury actively cycling at the Earth’s surface by approximately 3-fold, stimulating interest in this pollutant. Recent analytical advancements have allowed the use of mercury isotopic compositions to distinguish between specific natural and anthropogenic sources and offer an important tool to improve our understanding of global mercury cycling. Our speaker this month is Dr. Abir Biswas, Professor of Geology/Chemistry at The Evergreen State College.