Air pollution is among the most harmful risk factors for cancer.
The air we breathe especially in the cities, contains a mixture of different carcinogenic compounds - the exhaust of diesel engines, solvents, metals and dust. Most air polluting factors are transport, electricity production, emissions from industry and agriculture and domestic heating. Individual heating is the most problematic source in Slovenia, as many households are heated by burning wood, mostly in inappropriate furnaces. The European Environment Agency has published a report that in Europe more than 90 percent of the urban population is exposed to a level of air pollution by ozone and PM2.5 by the World Health Organization dangerous to human health.
Temperature inversion in combination with the heating season meant that, in those days, the concentration of PM10 in several Slovenian towns in central Slovenia exceeded the threshold. The Environment Agency advises people not burning in wood-fired ovens.