Cadmium is a metal which occurs in Nature in combination with zinc. Due to that reason the most common source of atmospheric air pollution is zinc production. Other metallurgy production may also be a source of cadmium pollution. It is discharged in the atmosphere from waste burning. It is as well contained in tobacco smoke.

Impact on human health
Cadmium enters the human organism through breading. Less than 50% of the inhaled cadmium gets absorbed. It is deposited in the liver, from where it is slowly transferred to the kidneys, where its highest concentrations are established. Cadmium excretion from the organism is very slow. About 10 years are necessary for excretion of one half of the quantity contained in the liver and the kidneys.
In addition to inhaling, cadmium may penetrate into the organism through the digestive tract. It deposits into the soil, from where it chances in the plants and via food - into the human body.
Kidneys prove to be the critical organ in the case of long-term exposure to low concentrations of cadmium. They get irreversibly damaged when the cadmium level in the kidney integument exceeds 200 mg/kg.
There is not enough information of the carcinogenic effect of cadmium and its eventual relation to the prostate gland and lung cancer, due to which the International Cancer Studies Agency classifies it into group 2B, i.e. with no proven health risk. Due to that reason the permissible concentrations of cadmium in the air are not defined on the basis of the carcinogenic effect.

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) - 0,00002 mg/m3;
- annual average LV (for 1 year exposure) - 0,00001 mg/m3.