An Air Hygiene Index was developed by the National Public Health Center in 2007 to provide information on the health risk associated with ambient air pollution for the different populations (e.g., children, elderly, people with chronic diseases). The evaluation takes into account the air pollutants with the highest risk (i.e., PM2.5, PM10, NO2, O3). The categorization is based on the latest national and international studies and recommendations, and the latest review of the categories was performed in 2020. The Air Hygiene Index contains four categories (satisfactory, moderate, unhealthy, dangerous). The previous day’s air quality data are used for the calculations and the meteorological forecast is used to provide information for the upcoming days. The Air Hygiene Index is calculated for all municipalities where monitoring station is in operation and the map is updated daily. General short-term health effects which might be associated with the exposure to air pollutants are described for each category. Furthermore, health messages are also available for the general public and special attention is paid for the communication towards the public by using different communication channels in the case of worsening air quality. Furthermore, frequently asked questions and answers are also available on the website of the Air Hygiene Index.
Based on our observations, the ambient air quality improved considerable in the past two decades due to effective measures implemented in the different sectors as well as favourable changes in the meteorological conditions (e.g., mild winters) were also contributed to lower concentrations; however, it is clear that further measures must be carried out in some sectors.