I work on the biogeochemical cycling of mercury (Hg). Mercury is a naturally occurring element, but humans have perturbed the natural cycle through activities such as mining, fossil fuel combustion, and industry. Mercury is a global health concern because of its ubiquitous presence in the environment and toxicity to humans and wildlife.
A multi-millennia legacy of mercury pollution
Humans have been releasing mercury to the air, soil, and water since antiquity. We are left with a long legacy of mercury pollution as a result and evidence suggests that the environment is enriched several-fold above background. Our current research efforts are focused on quantifying the extent to which mercury releases in the past affect the levels of mercury we see today.
Amos et al. (2013) in Global Biogeochemical Cycles
Gas-particle partitioning of atmospheric mercury
Mercury in the atmosphere can either exist as a gas or be associated with particles. The phase of mercury is important for understanding its fate in the atmosphere because the physical processes that remove gases and particles are different. Empirical relationships show that mercury partitioning is a function of temperature and the amount of particles in the air (the gas-phase is favored at warm temperatures with few particles in the air and the particle-phase is favored at cold temperatures with higher particle burdens). Taking gas-particle partitioning into account in global models has important implications for simulated deposition in the subtropics and high latitudes.
Amos et al. (2012) in Atmospheric Chemistry & Physics