Halomethanes are a group of organic compounds that consist of a methane molecule where one or more hydrogen atoms are replaced by halogen atoms, such as fluorine, chlorine, bromine, or iodine. They are commonly used in various industrial applications, including solvents, refrigerants, and as intermediates in chemical synthesis. These compounds can be found in the environment, often as byproducts of industrial processes. Some halomethanes, like chloroform and bromoform, are known to have harmful effects on human health and the environment, leading to concerns about their presence in drinking water and air pollution.