To understand how persistent hazardous industrial chemicals travel through the air and are deposited back on Earth's surface, we created a new computer model that combines meteorology and chemistry in clouds and clean air. Using the most recent global emissions data, this model represents the trajectory and changes of these chemicals, matching patterns in many areas and overlooking others. The work seeks to improve global monitoring and modeling of hazardous chemicals.

This paper introduces the Multi-Compartment Mercury (Hg) Modeling and Analysis Project (MCHgMAP) aimed at informing the effectiveness evaluations of two multilateral environmental agreements: the Minamata Convention on Mercury and the Convention on Long-Range Transboundary Air Pollution. The experimental design exploits a variety of models (atmospheric, land, oceanic ,and multimedia mass balance models) to assess the short- and long-term influences of anthropogenic Hg releases into the environment.

This paper combines a literature review with a 1D coupled Hg speciation and bioaccumulation model to assess how feeding strategy influences inorganic and methylmercury levels at the food web's base. We find that filter feeders have higher MeHg concentrations, while suspension feeders show very low MeHg. These results highlight feeding strategy as a key driver in MeHg bioaccumulation variability.

In this study, we analyze mercury bioaccumulation, including both methylated and inorganic Hg. While methylmercury is the primary toxin of concern, modeling inorganic Hg bioaccumulation reveals its role in marine mercury cycling. We find that bioaccumulation strongly influences mercury dynamics, increasing methylmercury levels. This effect is more pronounced in well-mixed coastal waters than in permanently stratified deep waters.

The mercury (Hg) form of most concern is monomethylmercury (MMHg⁺) due to its neurotoxicity and ability to bioaccumulate in seafood. Bioaccumulation in seafood occurs via bioconcentration (direct uptake) and biomagnification (trophic transfer). Our study separates these processes, showing that bioconcentration increases MMHg⁺ in high trophic level fish by 15 % per level, contributing 28–48 % of MMHg⁺ in Atlantic cod. These findings can be used to inform efficient Hg modeling strategies.