title: Urban-nonurban relationships of halocarbons.
mesh_terms: D000393:Air Pollutants / Q000032:analysis*; D006846:Hydrocarbons, Halogenated / Q000032:analysis*; D012423:Rural Health; D014504:Urban Health
chemical_list: D000393:Air Pollutants; D006846:Hydrocarbons, Halogenated