Qualité de l’air à Prague

What is the air quality index of Prague?

Prague is the capital and largest city in the Czech Republic which is situated on the Vitava River. In 2020 it had an estimated population of over 2.5 million people in the metropolitan area.

In 2019, according to the reputable Awiss air monitoring company, IQAir.com Prague attained a “Good “level based on figures suggested by the World Health Organisation (WHO) with a reading of 11.5 µg/m³. From May through to October it achieved the target figure of 10 µg/m³ or less. March and October brought a “Good” level of between 10 and 12 µg/m³ whilst the remaining 5 months classified it as “Moderate” with figures between 12.1 and 35.4 µg/m³. Overall showing an improvement on previous years of 15.6 µg/m³ in 2017 and 17.4 µg/m³ in 2018, which are “Moderate” readings.

What are the main sources of air pollution in Prague?

In Prague, air quality is one of the biggest environmental problems. The air is polluted mainly by airborne dust (solid particles PM10, PM2.5), ground-level ozone (O₃), nitrogen oxides (NO_x), benzo (a) pyrene (C₂₀H₁₂) and volatile organic compounds (VOC). The city of Prague has seen a large increase in vehicle numbers over the past decade. Exceeding the target permissible concentration in the air occurs in many areas of ​​Prague for the pollutant benzo (a) pyrene, mostly in the winter, when a significant source of emissions is the combustion of fossil fuels in local heating plants. Emissions of volatile organic compounds (VOC)s into the air are due to surface consumption of solvents and transportation, partly the automotive industry and printers. Volatile organic compounds (VOC)s together with nitrogen oxides (NO_x) contribute to the formation of ground-level ozone (O₃). There is, however, one part of the city which is considered to have good quality air.

Is the air quality in Prague getting better or worse?

Nitrogen dioxide (NO₂) is the most common pollutant in Prague’s air, specifically at the intersection of Sokolská and Ječná streets in the city centre. Other places in the vicinity of the main road or near the entrance/exit to the Blanka tunnel also showed high readings. In all cases, these are streets through which tens of thousands of cars pass on a daily basis. Among the localities with the highest values ​​of pollution are places in Brno, Pilsen which also did badly. The results were revealed by the Centre for the Environment, which from March to April measured nitrogen dioxide (NO₂) values ​​at 200 locations across nine regional cities. According to the study, the values ​​in these places ranged from 50 to 80 µg/m³. Values ​​above 33.5 µg/m³ can detrimentally affect human health.

What are the health effects of Prague’s polluted air?

Being subjected to nitrogen oxides (NO_x) may cause respiratory tract irritation, at high concentrations and prolonged exposure may cause asthma. Sulphur dioxide (SO₂) can cause coughs and respiratory tract irritation. It exacerbates existing asthma and bronchitis and is severely irritating to eyes and mucous membranes.

Carbon monoxide (CO) reduces the blood's capacity to carry oxygen to the tissues, which in turn strains the heart and can cause headaches, dizziness and nausea. At very high concentrations, it can lead to death. Ground-level ozone (O₃) causes eye, nose and throat irritation and damages the lungs and respiratory tract. Benzo (a) pyrene PAH (polyaromatic hydrocarbons) irritates the eyes and skin and has negative effects on the kidneys and the liver and may have carcinogenic and mutagenic effects.

The microscopic particulate matter known as PM2.5 is possibly the worst as, due to their small size, they can easily bypass the body’s defence system and lodge themselves deeply in the lungs. Here, they can pass into the bloodstream and eventually reach the heart. Like so many other pollutants, they are thought to be carcinogenic.

What can be done to improve Prague’s air quality?

The intensity of car traffic is not getting any smaller and many cars emit much more nitrogen oxide (NO) than the emission limits. And they do this right in the middle of the city where pedestrians walk amongst them. There are two solutions to this problem either adapt the engines so they produce fewer emissions and punish any excess emissions, or reduce and replace car traffic in other ways. The most common processes include toll collection, bans on certain types of vehicles entering cities and, possibly the most important, the introduction of low-emission zones.

Several energy sources are used to produce heat centrally. Various fuels and energy from the incineration of non-recyclable waste are used together for the joint production of electricity and heat. Thus, fuel is used more efficiently in central sources, and more importantly, the sources are mutually sustainable.

The main advantage of the joint production of heat and electricity is the maximum usability of thermal energy in fuel, including waste. In this way, energy is produced not only very efficiently, but also ecologically. However, production in this way cannot work without a district heating system. Thermal energy is produced centrally in one source and supplied via long-distance distribution to others, which, in addition to reducing the fuel intensity of energy, will also reduce greenhouse gas emissions, including carbon dioxide (CO₂).

The ecologically produced heat is supplied to the Prague heating system by the Malešice Waste Energy Utilization Facility (ZEVO), known among Prague residents as the "Malešice Incinerator". It annually processes 31,000 tons of municipal waste from all over Prague and produces 850 TJ of thermal energy. The heat produced in Malešice is supplied by the Prague Heating System to up to 20,000 households and large industrial areas in the locality.

The Prague heating system is connected to a 34-kilometre long heat feeder from the Mělník Power Plant. Here, heat is produced by the principle of cogeneration, which is the simultaneous and highly efficient production of heat and electricity. The Mělník power plant replaced more than 200 local boilers/heaters, which significantly reduced air pollution in Prague. The power plant has the most modern anti-emission technologies. By modifying the energy source, total emissions will continue to be reduced.

Can the smog in Prague be controlled?

The current level of smog can be found as part of the information provided by the Department of Environmental Protection of the City of Prague working in partnership with the Czech Hydrometeorological Institute.