Proper indicators for the presentation of changes in the concn. of air pollutants in a multi-year period on a single site and in the country on the example of particulate matter 10 pm (PM10) concns. were selected. As PM10 indicators, the ay. annual concn. Sa and the S90.4 percentile of the annual series of daily concns. of PM10 were used. The indicator for the whole territory of Poland was calcd. for each year in 2 stages, as a weighted ay. of the ay. indicators found for the particular provinces.