In literature on arsenic toxicology, little is known about the concentration of arsenic in the air. Inhalation exposure to arsenic is mainly related to the presence of stationary sources of arsenic, such as pyrometallurgical nonferrous metal installations, e.g., copper smelters active in the past and present. Inhalation exposure is important in workers who are occupationally exposed to arsenic and not very important in a population environmentally exposed to this metalloid. Copper smelters emit arsenic into the air in the form of dust and aerosols. The size of the molecules of arsenic compounds in the air depends on the state of steelworks products (metallurgical vapors contain small particles with a diameter of <1 μm, and solid metallurgical wastes contain larger particles with a diameter of >1 μm). Metallurgical smokes are more dangerous to the body because small particles easily penetrate through the respiratory tract and enter the bloodstream. They also have a greater bioavailability following from a larger surface to volume ratio. In the world population, the main route of absorption of arsenic is the digestive tract. The main source of exposure is drinking water, and the highest degree of arsenic contamination occurs in Australia, New Zealand, Thailand, India, Argentina, and Mexico. Arsenic in food can be a significant risk, especially for infants and young children. The assessment of arsenic impact on human health requires the assessment of total exposure to arsenic, in which the inhalation route is a minor part.