Air quality in Zilina

Is Žilina currently a very polluted city?

Žilina is a city in north-western Slovakia. It is located approximately 200 kilometres from the capital, Bratislava and is extremely close to both the borders with Poland and the Czech Republic. It is the fourth largest city in Slovakia as shown by the census from the end of 2020 which estimated the population to be 82,000 city residents and 160,000 when the metropolitan area is also included. It is an important industrial centre, conveniently placed on the Váh river.

At the start of 2022, Žilina was experiencing a period of air quality classed as being “Unhealthy for sensitive groups” with a US AQI reading of 124. This United States Air Quality Index number is an internationally used set of metrics supported by the World Health Organisation (WHO) and is used to compare the air quality in different cities throughout the world using comparable standards. It is calculated by using the levels of the six most commonly found pollutants such as nitrogen dioxide, sulphur dioxide, ozone, carbon monoxide and both sizes of particulate matter, which are PM2.5 and PM10. If all six figures are not always available in which case, a level is calculated by using what data there is. There were three of these main pollutants measured in Zilina which were PM2.5 - 45 µg/m³, PM10 - 51 µg/m³ and nitrogen dioxide (NO₂) - 39 µg/m³.

This level of PM2.5 is four and a half times above the recommended safe level of 10 µg/m³ as suggested by the World Health Organisation (WHO) as being an acceptable level. Although no amount of air pollution is considered to be safe.

When air pollution is classified as being “Unhealthy for sensitive groups” the given advice would be to remain indoors as much as possible, closing doors and windows to prevent the ingress of more polluted air. The use of an air purifier would be advantageous if one is available but ensure it is set to recirculate the existing air and not import more dirty air from outside. Those who are more sensitive to poor quality air should avoid venturing outside until it improves. If this is unavoidable, then a good quality face mask should be worn at all times. All types of outdoor exercise should be avoided until the air quality improves. There is a downloadable app from AirVisual.com which is suitable for all operating systems and gives the latest information regarding air quality in real-time.

Does the level of air pollution vary much throughout the year in Žilina?

Air quality can be affected by many things, therefore it can and does change rapidly depending on the local conditions. Looking back at the 2020 figures published by IQAir.com, it can be seen that the months between the start of May to the end of September enjoyed “Good” air quality with figures between 10.1 and 12 µg/m³. The best month was July with a figure of 10.2 µg/m³. February through April and October through December saw air quality from the “Moderate” bracket with readings between 12.1and 25.4 µg/m³. This just leaves the month of January when the air quality was at its worst. The reading of 37.3 µg/m³ put it firmly in the class of being “Unhealthy for sensitive groups”. To be classified as such, the figures must fall between 35.5 and 55.4 µg/m³.

Records regarding air pollution were first kept in 2017 when a figure of 25.9 µg/m³ was recorded. The following year saw an improvement with a reading of 21.8 µg/m³ and the trend continued in 2019 with a figure of 18.6 µg/m³. 2020 saw another improvement with an annual average of 17.2 µg/m³, but this lower figure was almost expected because it would have been affected by the COVID-19 pandemic as many vehicles were no longer in daily use because the offices were closed and the staff encouraged to work from home, in an attempt to halt the spread of the virus. Many factories and non-essential production units were also required to close which removed their emissions from the atmosphere, albeit on a temporary basis. Worldwide, cities reported a much better quality of air due to the general lack of traffic pollution in city centres due to the pandemic.

Where does all the air pollution come from in Žilina?

One of the most serious environmental problems in Slovakia is air pollution. Environmental reports from the Slovak Hydrometeorological Institute, as well as the Air Quality in Europe report from the European Environment Agency, agree that the most significant problem is air pollution with particulate matter PM10 and PM2.5. Exceeding the limit values is also recorded by Slovak cities. A significant source of solid particles is local heating, transport and resuspension of particles from the road surface. The city of Žilina has taken several measures in the past period to mitigate the impact on the environment and the state of the air in the future.

Can anything be done to improve air quality in Žilina?

There are some ways to reduce emissions from a solid-fuel family home. Solid fuel should be sufficiently overdried. It is optimal to burn pieces of wood with a humidity below 20 per cent. Less energy is used to evaporate water from the fuel, more energy is used for domestic heat. The boiler and chimney must be cleaned regularly. It is also not recommended to incinerate waste, as harmful emissions also flow into the interior. Burning chlorinated materials, such as polyvinyl chloride (PVC) produces highly toxic compounds. A temperature above 1,200 ˚C is required to dispose of such materials. Dioxins and formaldehyde can also be released by burning chemically treated wood, such as old pallets, broken furniture or painted boards. Long-term inhalation of polluted air is the cause of many respiratory diseases.

The city of Žilina is combating air pollution with several measures. In the field of transport, it is mainly a matter of long-term support for alternative modes of transport. Congestion of public transport connections has been introduced in the city, its preference and the entry of cars into the pedestrian zone is regulated. Cycling has long been supported by the construction of new cycle paths, additional cycling infrastructure, bike sharing and shared electric scooters are popular.

What are the detrimental effects of breathing in polluted air?

Particulate matter (PM) is the air pollutant that causes the greatest damage to human health in Europe. Think of them as particles that are so light that they can flow in the air. Some of these particles are so small (one-thirtieth to one-fifth the diameter of a human hair) that they not only get deep into our lungs, but can also enter our bloodstream as oxygen.

These particles can consist of various chemical components and their impact on our health and the environment depends on their composition. Some heavy metals such as arsenic, cadmium, mercury and nickel can also be found in particulate matter.