The Hungarian Air Quality Index allows users to understand more about air quality where they live, work or travel. Displaying up-to-date information for Hungary, users can gain insights into the air quality in individual regions and cities. The Index is based on concentration values of pollutants listed below:

·       Benzene (C₆H₆);

·       Carbon monoxide (CO);

·       Nitrogen dioxide (NO₂);

·       Ozone (O₃);

·       Particulate matter (PM₁₀);

·       Fine particulate matter (PM_2,5);

·       Sulphur dioxide (SO₂);

It reflects the potential impact of air quality on health, driven by the pollutant for which concentrations are poorest due to associated health impacts. The index is calculated hourly for 58 fixed air quality monitoring stations and 2 mobile stations, using up-to-date data reported Hungarian Air Quality Network.

These data are not formally verified and must be used only for information purposes.

Hungarian legislation sets air quality standards for both short-term (hourly or daily) and long-term (annual) air quality levels. Standards for long-term levels are stricter than for short-term levels since serious health effects may occur from long-term exposure to pollutants. The Index indicates the short-term air quality situation. It does not reflect the long-term (annual) air quality situation, which may differ significantly.

The air quality index is not a tool for checking compliance with air quality standards and cannot be used for this purpose.

Methodology

The Index uses up to date air quality data reported every hour by Hungarian Government Offices. Concentrations values determine the index level that reflects air quality at each monitoring station. The index corresponds to the poorest level for any of the pollutants, according to the table shown below. Circles on the map represent the locations of air quality monitoring stations. The colours reflect air quality at the given hour at that station.

Stations missing data for certain pollutants

To avoid leaving out stations that do not report data for all pollutants or for which missing, the index is calculated for all monitoring stations with data for at least one pollutant. Those stations that do not report data at all, the index is not calculated and the station is coloured as grey. Grey dots indicate stations for which no data have been reported for 3 days. After this time the station will not appear on the map.

Averaging time for pollutants

For CO, NO₂, O₃ and SO₂, hourly concentrations are fed into the calculation of the index. For benzene (C₆H₆), PM₁₀ and PM_2.5, the 24-hour running means for the past 24 hours are fed into the calculation of the index. A 24-hour running mean will be calculated if there are values for at least 18 out of the 24 hours.

Bands of concentrations and index levels

The bands are based on the relative risks associated to short-term exposure to PM_2.5, O₃ and NO₂, as defined by the World Health Organization in its report on the Health Risks of Air Pollution in Europe project (HRAPIE project report).

The relative risk of exposure to PM_2.5 is taken as basis for driving the index, specifically the increase in the risk of mortality per 10 µg/m³ increase in the daily mean concentration of PM_2.5.

Assuming linearity across the relative risks functions for O₃ and NO₂, we calculate the concentrations of these pollutants that pose an equivalent relative risk to a 10 µg/m³ increase in the daily mean of PM_2.5.

For PM₁₀ concentrations, a constant ratio between PM₁₀ and PM_2.5 of 1:2 is assumed, in line with the World Health Organization´s air quality guidelines for Europe.

For SO₂, the bands reflect the limit values set under the EU Air Quality Directive.

Air quality measurements that exceed the maximum values in the “extremely poor” category are not taken into account for the index calculation, since these values are typically found to be erroneous.

Health messages

The index bands are complemented by health related messages that provide recommendations for both the general population and sensitive populations. The latter includes both adults and children with respiratory problems and adults with heart conditions.

Additional information

When clicking on a station on the map, a pop-up window appears with the following additional information:

1.   The name of the station.

2.   The air quality index of the main pollutants at that station over the last 3 days. The last colour shows the actual index.

3.    On the “Air Quality” subpage the last hourly concentration data can be seen. This data cannot be seen on the main website.

4.   “Further data” links the measurement data of the automatic network.

Attention! On the “Air Quality” subpage in the pop-up window the values indicate the last hourly concentrations for all components. The index reflects the hourly concentrations for CO, NO₂, O₃ and SO₂ and the 24 hour running means for C₆H₆ (benzene), PM₁₀ and PM_2.5 . There may be a case for these pollutants where the index shows worse or better air quality than the hourly value.

Further information

Further information on air quality:

-          Under „Measurement data”: up-to-date air quality measurement

-          Under „Evaluations”: air quality statistics, diagrams and maps for the main pollutants

-          Under „Information”: information on the air quality network, air quality zones, AQ index and legislation

The European Air Quality Index – which is the base of the Hungarian air quality index – was developed jointly by the European Commission’s Directorate General for Environment and the European Environment Agency to inform citizens and public authorities about the recent air quality status across Europe.