摘要:The sources of gaseous and particulate (PM) pollutants in Polish cities are mainly: municipal sector, industry, emissions from the road transport and the upstream emission (pollution “flowing” to the cities, derived from emission sources located outside of cities). The residents of the cities are mainly exposed to air pollutants from low-emission sources (i.e. municipal sector and road traffic). In the paper, the results of the study from field campaign, conducted in January of 2016 in Wroclaw will be presented. During the field campaign the 24-h concentrations of submicron particulate matter (PM 1 ) and 24-h concentrations of selected PM 1 -bound heavy metals were determined. The cancer risk associated with inhalation exposure to arsenic, nickel, and cadmium to the city’s residents, based on the US Environmental Protection Agency (US EPA) standards methodology including the so-called lifelong chronic exposure of adult and child, was calculated. Measurements results showed that in Wroclaw during the winter season in 2016 the 24-h concentrations of PM 1 -bound arsenic, nickel and cadmium ranged from 0.51 to 4.26 ng/m 3 , 0.21–52.89 ng/m 3 and 0.08–1.01 ng/m 3 , respectively. Obtained calculations results of cancer risk values for inhalation exposure to arsenic were: for men: 6.11·10 −6 , women: 7.30·10 −6 , children: 14.90·10 −6 , to nickel: for men: 1.91·10 −6 , women: 2.29·10 −6 , children: 4.67·10 −6 , to cadmium: for men: 0.37·10 −6 , women: 0.44·10 −6 , children: 0.91·10 −6 . The values obtained for inhalation exposure among children indicated the high potential risk of cancer, mainly for arsenic exposure.