Chromium more often occurs in nature as a three-valency and relatively seldom as a six-valency metal. Chromium salts are used for pigment production, in leather industry, for corrosion preventive chromium plating, etc. Air pollution data are scanty.

Impact on human health
Six-valency chromium has harmful effect on health, due to its toxicity and carcinogenic action. The most common way of human body penetration by the chromium compounds is through inhalation. About 50% of the chromium is eliminated through urine. A considerable part gets accumulated in the bones and soft tissues. Whereas three-valency chromium is a bio-element, toxic effects are associated with six-valency chromium. The risk-related organ with respect to six-valency chromium is the lung. According to the International Cancer Studies Agency chromium is classified as group I human carcinogenic substance.

The following limit values for cadmium content in the atmospheric air are set by our legislation Regulation No. 14 (State Gazette No. 88/1997, amended SG No. 46/1999, amended and supplemented, SG No. 8/2002): - 24 hour average LV (for 24-hour exposure) - 0,00001 mg/m3;
- annual average LV (for 1 year exposure) - 0,00005 mg/m3.