Bratislava air quality map

What information is generally available on the air pollution map for Bratislava?

The air pollution map for Bratislava is very accessible once the main city page is opened. It can be found at the top left-hand side of this main page and a click anywhere on the map will open up that page.

Once opened, the viewer will probably notice the overall background colour of the map. Currently, it is greenish/yellow which would classify it as being “Good” to “Moderate”. The explanation of the meaning of the colours is explained in the legend at the foot of the page. Generally, the colours range from pale green to dark maroon. The other noticeable thing will be the coloured discs which are dotted around the map. These represent the location of the ground-level air monitoring stations. If they are overlapping each other, they will soon separate once the map is slightly expanded. Each station can then be selected and another page will open with all the information about that particular part of the city.

Each disc displays a number which is the US AQI reading from that station. It is calculated by measuring the levels of up to six of the most prolific air pollutants found in the city air. It is then used as a metric when comparing different air quality in cities across the globe. It is endorsed by the World Health Organisation (WHO).

Looking back to the main city page, it can be seen that in August 2022 Bratislava was experiencing a period of “Moderate” air quality with a US AQI reading of 68. There were four main pollutants measured but the level of PM2.5 is the one considered to be the benchmark. The recorded level was 20 µg/m³ which is four times higher than the WHO recommended target level of 5 µg/m³.

What other information can be found on the air pollution map for Bratislava?

When the air pollution map for Bratislava is viewed in full-screen mode, a list of four options will appear down the left-hand side of the screen. These can all be chosen individually and deactivated if required.

The first option reveals the location of all of the ground-level air monitoring stations situated in and around the city and its environs. As stated in the first paragraph, these appear as coloured discs each of which displays its US AQI reading in the centre. Sometimes the discs appear to sit on top of each other, but they will separate once the map is expanded.

The second option reveals the location of any fires which may be burning in the vicinity. In August 2022, there were no fires burning in the vicinity. If fires were detected, then option four needs to be considered at the same time. This option shows the direction of the prevailing winds and gives an indication of airspeed. This can be a good guide as to whether or not the ensuing smoke from the fire will affect the city or not.

Option three is perhaps the most theatrical in that it can change the entire colour of the map to reflect the overall air quality. If the colour is a little too distracting, when it is deactivated, the map will revert to a more natural set of colours.

Across on the far right of the screen can be seen a table which ranks world cities according to their levels of air pollution. They are ranked according to their US AQI reading.

Directly below the map can be seen the number of stations which actively provide the data regarding air quality in the city. There are currently four stations in and around the city. Three are operated by the Czech Hydrometeorological Institute and the fourth is by the Slovensky Hydrometeorologicky Ustav (SHMU).

Can areas of high pollution be readily seen on the air pollution map for Bratislava?

There are two main routes to find the most heavily polluted area within the city of Bratislava. The first would be to look at the various discs on the map and choose the one with the darkest colour or highest US AQI reading. Or by scrolling down to below the map, the most polluted stations are listed in descending order. Currently, the dirtiest area of the city is around the Bratislava, Kamenné nám station which returned a US AQI reading of 78 which is classified as being “Moderate”.

Below this list is the one which places the stations in order of their popularity and the number of followers they each have. The most popular is the Kamenné nám station with 742 followers.

Is the source of air pollution shown on the air quality map for Bratislava?

Air pollution in Bratislava is a problem that should definitely not be underestimated. Slovakia is facing a lawsuit brought by the European Commission to the European Court of Justice due to poor air quality. The subject of the lawsuit is exceeding the limit value for solid pollutants and failure to take adequate measures to improve air quality.

In Bratislava, according to the Ministry of the Environment of the Slovak Republic, the biggest problem is with nitrogen dioxide, which comes primarily from transport. According to the Study of Air Quality in the Bratislava SHMÚ agglomeration, in terms of PM and benzo(a)pyrene emissions, the main source of emissions is from the transport sector and, to a lesser extent, the heating of households connected to central heating sources.

Road transport is largely responsible for carbon dioxide and benzene emissions. The main source of sulphur dioxide emissions is industry, and specifically, the Slovnaft refinery has a high share of benzene and nitrogen dioxide emissions. “The major industrial source of pollution in Bratislava is the Slovnaft refinery," states the study.

What is PM2.5 which is quoted so often on the air pollution map for Bratislava?

Particulate Matter (PM) is a mixture of solid and liquid particles that are suspended in the air. These are categorized into coarse, fine and ultrafine. Coarse particles have a diameter of 2.5 micrometres to 10 micrometres (about 25 to 100 times thinner than a human hair), are relatively heavier and thus tend to settle. Dust, spores and pollen are some examples. PM2.5 refers to particles that have a diameter of less than 2.5 micrometres (more than 100 times thinner than a human hair) and remain suspended for longer.

These particles are formed as a result of burning fuel and chemical reactions that take place in the atmosphere. Natural processes such as forest fires also contribute to PM2.5 in the air. These particles are also the primary reason for the occurrence of smog.