Duration of the PM2.5 particles in Lombardy and Macedonia

For this case-study annual time series consisting of daily average concentrations of fine particulates known as PM2.5 are used. The yearly concentrations are consisted into separate data sets. Measuring was done in 11 stations across Lombardy and Macedonia, for a given time-period of 5 years, from 2012-2017. Analysis performed include duration of events where the concentration of pollutant is exceeding certain threshold, where the event is represented by a series of days when the fixed threshold is exceeded without interruption. In order to calculate the total time (TET), number of events (NET) and the duration of the events of exceedance annually, 10 to 16 concentration thresholds ranging from 10 μg m-3 to 90 and 150 μg m-3 with a step of 10 μg m-3, and a special threshold of 25 μg m-3 were used. Followed by parameterized empirical or theoretical models of the yearly data, made to explain the observed data (NET, TET, and the duration of the events of exceedance), and can be further used to estimate concentration levels in future scenarios. Due to the higher concentration levels of PM2.5 than the one regarded as limit by the EU, this case-study including Lombardy and Macedonia makes assessments of the frequency of the duration episodes in order to attain a target average concentration limit for PM2.5 where the annual concentration will be in compliance with the limit.