Other airborne sources include emissions from chemical processing, other industries, and municipal waste incinerators.
Smoking is another important source of cyanide.
Cyanide may be found in water from discharges from organic chemical industries, iron and steel works, and wastewater treatment facilities. Exposure to cyanide may also occur in the workplace. The electroplating, metallurgical, firefighting, steel manufacturing, and metal cleaning industries are a few of the workplaces where exposure may occur. However, because the body normally contains very small amounts of these chemicals, these measurements are only useful when exposure to relatively large amounts of cyanide has occurred. Cyanide is extremely toxic to humans.