Fluorides are released into the environment naturally through the weathering and dissolution of minerals, the emissions from volcanoes and from marine aerosols (WHO, 2002). Fluorides are also released into the environment via coal combustion and process waters and waste from various industrial processes, including steel manufacture, primary aluminium, copper and nickel production, phosphate ore processing, phosphate fertilizer production and use, petroleum refining, glass, brick and ceramic manufacturing, and glue and adhesive production (WHO, 2002).
Based on available data, phosphate ore production and use as well as aluminium
manufacture are the major industrial sources of fluoride release into the environment.