Methylmercury is produced indirectly by which process?

Methylmercury is produced indirectly by which process?

• A. Photosynthesis
• B. Combustion of coal
• C. Oceanic deposition
• D. Industrial smelting

Answer: (B)

Methylmercury forms when inorganic mercury is transformed by certain microbes in aquatic environments. The key starting point is mercury released into the environment, which happens prominently when coal is burned. This combustion sends mercury into the atmosphere, where it eventually settles into water bodies. There, bacteria in sediments convert inorganic mercury into methylmercury, a form that readily bioaccumulates up the food chain, especially in fish. So the burning of coal is the indirect source that introduces mercury into ecosystems and sets off the microbial methylation that creates methylmercury. Photosynthesis doesn’t produce mercury, oceanic deposition is just part of the transport process, and while smelting can release mercury, the main indirect producer in this context is coal combustion.

Methylmercury forms when inorganic mercury is transformed by certain microbes in aquatic environments. The key starting point is mercury released into the environment, which happens prominently when coal is burned. This combustion sends mercury into the atmosphere, where it eventually settles into water bodies. There, bacteria in sediments convert inorganic mercury into methylmercury, a form that readily bioaccumulates up the food chain, especially in fish. So the burning of coal is the indirect source that introduces mercury into ecosystems and sets off the microbial methylation that creates methylmercury. Photosynthesis doesn’t produce mercury, oceanic deposition is just part of the transport process, and while smelting can release mercury, the main indirect producer in this context is coal combustion.