Qualité de l’air à Linz

What is the air quality index of Linz?

Linz is the capital of Upper Austria and the third-largest city in Austria. It is located in the north of the country some 30 kilometres south of the Czech border. It straddles the Danube River. In 2018 it had an estimated population of just over 200,000 people.

An interesting fact is that Linz has approximately 157,000 jobs of which its population cannot possibly fill all the vacancies. This leads to a huge commute from the surrounding area on a regular basis, but this in turn leads to tremendous traffic problems and excess pollution.

At the beginning of 2021, Linz was experiencing a period of “Moderate” quality air with a US AQI reading of 59. This classification is in line with the recommendations from the World Health Organisation (WHO). The recorded levels of the pollutants were as follows: PM2.5 - 10 µg/m³, PM10 - 14 µg/m³, nitrogen dioxide (NO₂) - 34 µg/m³, sulphur dioxide (SO₂) - 2 µg/m³ and carbon monoxide (CO) - 350 µg/m³.

With a level such as this, the advice is to close doors and windows to prevent the ingress of dirty air. Those of a sensitive disposition should avoid outdoor activity until the air quality improves.

What is the main source of air pollution in Linz?

As with most large cities throughout the world, the main source of air pollution comes from the emissions produced by vehicles burning fossil fuels. After that, the next major source comes from industrial practices and power plants and the emissions which they create. During the colder winter months, home heating systems which burn wood produce a large amount of small particulate matter. Weather conditions often occur in which the air exchange is severely restricted. The year-round constant emissions of fine dust and nitrogen oxides from traffic are therefore particularly noticeable during this time of year. Pollutants are often trapped in the layer of air closer to the ground due to thermal inversion. Colder air is trapped underneath an upper layer of warmer air. Because air near the base of an inversion tends to be cool, fog or smog is frequently present there.

A major cause of the extremely high levels of dust precipitation in the Linz area is, as shown in a report on the air quality of Linz, essentially in the two most important industrial sectors of fertiliser production and steel production.

Why is air quality so poor in Linz?

Pollutants enter our air primarily through industrial production processes, exhaust gases from road traffic and through combustion through heating rooms and are referred to as emissions. These emissions are diluted as a result of wind and air turbulence caused by solar radiation. The effect of the diluted contaminants is called immission.

Special weather conditions such as calm, fog (often a combination of both) have the consequence that the dilution of the emitted substances is limited, which can lead to increased air pollution and even smog.

However, the latter has not been an issue in Linz for many years due to the numerous measures taken in the past.

What can be done to improve the air quality in Linz?

The state of Upper Austria collects data on air quality in Linz at five (excluding SO₂, PM2.5, CO) or seven measuring stations. The following pollutants are measured: fine dust (PM10), fine dust (PM2.5), carbon monoxide (CO), sulphur dioxide (SO₂), hydrogen sulphide (H₂S), nitrogen dioxide (NO₂) and nitrogen monoxide (NO). For this purpose, general data on wind speed and wind direction are documented. In Linz, the limit values for nitrogen oxides are exceeded, sometimes dramatically. The fine dust pollution is also often above the limit values.

It is emphasised that the exposure values with harmful pollutants have decreased, but it is downplayed that these are still in many cases above the EU limit values, well above the WHO limit values. In comparison, the city of Linz points out that there are significantly worse environmental conditions in Athens, Milan or Zagreb. But that doesn't mean that the situation in Linz is even remotely good. It just means that there are significantly worse conditions elsewhere.

Limit values indicate that there are no health risks as long as the limit values are not exceeded over a specified period of time. They also ignore the fact that people are not standardised and have different levels of sensitivity to pollutants, for example children, the elderly, pregnant women and those with pre-existing medical conditions.

Nor do they do not take into account interactions between different pollutants and their accumulation in humans. They do not allow a reliable statement about long-term effects.Above all, limit values can be negotiated and altered.

Limit values are the result of a political decision on which scientists have an impact through their research results, but which are essentially influenced by powerful lobbies in industry and business, including multi-national organisations and international corporations. Accordingly, different limit values for the same pollutants apply in different countries.

What are the effects of breathing Linz’s poor quality air?

Far too little is known in detail about the health risks of air pollution. This may also be due to the fact that air pollution, especially when it is not visible, receives little attention from the population. In addition, in the case of lung cancer and questions about a connection with air pollution, doctors usually answer that the causes are multifactorial and that these often date back more than twenty years. This is probably also used by politicians as a superficial argument for not really doing anything, at least far too little, to protect the population. Sometimes you get the impression that politicians act according to the motto: out of sight, out of mind.

However, the situation is slowly changing as more and more people are now aware of air pollution and the possible dangers it can cause. This is partly due to the COVID-19 pandemic in 2020 when it was impossible not to notice the local environment.

Air pollution is a proven cause of illness and premature death. The greatest danger comes from excessive pollution with fine dust and ozone.

For people who are already ill, air pollution represents a further burden. The higher the pollution in the air (e.g. on busy streets), the shorter the symptom-free phases. The polluted air leads to a reduction in the average lung capacity as well as more emergency consultations and hospital admissions for respiratory diseases. It also reduces life expectancy due to cardiovascular and respiratory diseases, including lung cancer.