Measurements for the needs of calculating national indicator were started in 2010. According to the above the national average exposure indicator for 2010 was calculated as the arithmetic mean of the average annual PM2.5 concentrations in 2011. The index for 2011 was calculated as the arithmetic mean of the average annual PM2.5 concentrations in 2010-2011 in 2012. For 2012 and subsequent years, the national average exposure indicator is calculated as the arithmetic average of the average annual PM2,5 concentrations from the last three years (eg for 2015 the indicator was calculated in 2016 as the arithmetic mean of the average annual PM2,5 concentrations for 2013-2015).

For the purposes of calculating national indicator, 30 measuring stations were created whose locations were approved by the Chief Inspectorate of Environmental Protection. Measuring stations are located in areas with a very high population density remote from dust emission sources. In cities over 100,000 inhabitants and agglomerations not exceeding 1 million inhabitants, these measurements are carried out on one measuring station. In the Warsaw Agglomeration and the Upper Silesian Agglomeration, measurements are carried out on two measurement stations. Detailed information on the location of air pollutant measuring stations PM2,5 for the purposes of calculating KW are included in voivodship environmental monitoring programs. Measurements are made using low-flow PM2.5 dust collectors, i.e. the reference method by voivodships inspectorates for environmental protection. Measurements are carried out continuously.