Abstract
Some of the major stressors of air quality in the urban areas are nitrogen oxides, ozone and suspended particles. The effect of air
pollution on respiratory diseases can increase considerably at high levels of pollution and might trigger asthma symptoms. Longterm
exposure can increase the rate of respiratory infections and symptoms at population level, but particularly in children. The
goal was to analyze with statistical techniques the pollutant concentrations (NO, NO2, and SO2) recorded by 15 automated
monitoring stations, to establish weekdays-weekend trends in various towns of the South Muntenia Region during cold months
when residential heating contributes to the overall emissions. Raw data of the monitored parameters were acquired from 7
stations for NO and NO2, and 14 stations for SO2. Data acquisition and processing were performed between November 15, 2013
and February 28, 2014 and hourly-recorded time series were characterized for central tendency, dispersion and distribution. The
statistical analysis determined the degree of differentiation between different sites and time intervals of the monitored pollutants
using the screening of air quality trends based on hourly concentrations of each weekday using a specific grouping of data. The
results support the characterization of weekday/weekend patterns in air pollutant concentrations in several urban areas of
Southern Romania, where air pollution data were available: 4 cities (NO, NO2) i.e., Ploiesti, Slobozia, Turnu Magurele, and
Giurgiu, respectively 6 cities (SO2), i.e., Ploiesti, Pitesti, Cimpulung, Giurgiu, Alexandria and Turnu Magurele.