Qualité de l’air à Thessaloniki

What is the current level of air pollution in Thessaloniki?

Thessaloniki, also known as Thessalonica in English, Saloniki or Salonica is the second-largest city in Greece. According to a survey conducted in 2011, Thessaloniki had an estimated population of over 824,000 people in the urban area and over another million in the metropolitan area. It is Greece’s second major economic, industrial, commercial and political centre as well as a major transportation hub.

Towards the end of 2021, Thessaloniki was experiencing a period of “Moderate” air quality with a US AQI reading of 65. This United States Air Quality Index number is calculated using the levels of six of the most commonly occurring air pollutants, such as nitrogen dioxide, sulphur dioxide, ozone, carbon monoxide and both sizes of particulate matter, which are PM2.5 and PM10. It can then be used as the metric when comparing air quality in other cities around the world. If data is unavailable for all 6 pollutants, a figure can still be calculated by using what figures there are. The only pollutant measured in Thessaloniki was PM2.5 which was 18.8 µg/m³.

This level of PM2.5 is almost twice 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 the level of air pollution is classed as “Moderate”, the given advice would be to remain indoors as much as possible, closing all doors and windows to prevent the ingress of more polluted air. Those of a sensitive disposition should limit their time spent outside and should always wear a good quality face mask when doing so. For up-to-date information about air quality, there is an app available from AirVisual which is downloadable for all mobile devices.

Does the level of air pollution vary throughout the year in Thessaloniki?

Air quality is very volatile as it is subject to many external influencing factors such as meteorological and atmospheric changes.

Looking back at the figures for 2020, released by IQAir.com, it can be seen that the month with the best quality air was June with a figure of 11.8 µg/m³ which is classed as being “Good”. The month of January saw figures from the “Unhealthy for sensitive groups” category with a figure of 40.1 µg/m³. The remaining ten months of the year saw figures from the “Moderate” category with readings between 12.1 and 35.4 µg/m³. Out of these months, the best was May with a reading of 13 µg/m³, the worst was November with a reading of 29.4 µg/m³.

Records for air pollution were first held in 2019 when a figure of 23.3 µg/m³ was recorded. An improvement was seen in 2020 when the figure was 20.9 µg/m³, however, this reading may have been affected by the COVID-19 situation as many vehicles were no longer in daily use because the offices were closed, 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.

What is the chief source of air pollution in Thessaloniki?

The emissions of pollutants into the atmosphere of Thessaloniki are due to the following factors: road transport is the main source of nitrogen oxides (NOx) and carbon monoxide (CO). Also, the industry and the refinery are the main source of sulphur dioxide (SO₂), but as the study notes, no excesses are observed and the quality of the atmosphere in relation to the sulphur dioxide (SO₂) emissions is characterised as good.

Regarding the PM10 suspended particles, for which there is a serious problem and have led to the referral of Greece to the European Court, the main sources are: central heating, industry, the burning of agricultural biomass, the use of fertilizers and road transport.

The presence of suspended particles in the area of Thessaloniki during the winter months is increased, due to the operation of fireplaces (biomass burning), increased traffic and industrial activity.

There are several external sources of pollution surrounding Greece, for example in the south there are desert areas in North Africa such as the Sahara, in the east there are countries above the Black Sea where there is a systematic biomass burning from agriculture and in the northwest, there are the industrial areas of Central Europe.

What can be done to improve air quality in Thessaloniki?

On 1^st July 2020, the General Directorate of Development and Environment - sent to the Ministry of Environment and Energy the results of a study on "Preparation of an operational plan to address air pollution" and expects the reaction of the ministry. As noted in the relevant document, the measures required are control - enforcement, investment, organizational, institutional and citizen information, while relating to industry, heating, transport, agriculture and the operation of the city. Most of them require legislation and to a small extent relate to the responsibilities of the Local Government at this stage.

Several municipalities, including the municipality of Thessaloniki, use the financial subsidies offered to them and are already proceeding with the supply of electric vehicles to meet their needs. Charging units are in the process of being installed.

What are the health impacts of breathing dirty air in Thessaloniki?

Although air pollution affects everyone, it does not affect everyone to the same degree and in the same way. More people are exposed to air pollution in urban areas due to higher population densities. Some groups are more vulnerable, and include people with cardiovascular and respiratory diseases, people with reactive airways and airway allergies, the elderly and infants.

Carbon dioxide is the gas with the biggest cause of Global Warming in the so-called greenhouse effect. It comes from the combustion of coal, oil and natural gas. In high concentrations it is toxic and can cause death.

Carbon monoxide is due to the incomplete combustion of fuels such as gasoline, oil and firewood. When it is inhaled, it is transferred to the blood, where it prevents oxygen delivery. In small relationships it feels like fatigue, headaches and dizziness, and in a large relationship it can be fatal.

Nitrogen oxides are a cause of smog (fog and smoke) (nitrogen oxides with volatile organic compounds common respiratory disorders) and the cause of acid rain (it damages vegetation and water in lakes and rivers, and eliminates bacteria that are food for fish). It is created by burning gasoline, coal and other fuels.