Qualité de l’air à Tabriz

What is the air quality index of Tabriz?

Tabriz is situated in the northwest of Iran in the Quru River valley. In 2016 it had an estimated population of over 1.7 million people.

At the beginning of 2021, Tabriz was experiencing some very poor quality air with a US AQI figure of 143 which classified it as “Unhealthy for sensitive groups” according to the recommendation by the World Health Organisation (WHO). The recorded concentrations of the pollutants were as follows: PM2.5 - 52.6 µg/m³, PM10 - 65.2 µg/m³, ozone (O₃) - 20 µg/m³ and nitrogen dioxide (NO₂) - 20 µg/m³. With such elevated concentrations, it is advisable to wear a good quality mask when venturing outside. Doors and windows should be kept closed to prevent the ingress of dirty air into the house. Outdoor exercise is not recommended until the air quality shows signs of improvement. The use of an air purifier would be beneficial if one is available.

What is the main source of air pollution in Tabriz?

Fixed sources such as industries, factories, refineries, gas stations, power plants, offices and mobile sources of pollutants such as gasoline vehicles and diesel vehicles have a significant role in air pollution in various cities, especially metropolises. The results of a local study show that the share of particulate matter emission from fixed sources is between 75 to 95% per cent and the share of mobile sources is between 5 to 25 per cent and the share of fixed sources, including industries in air pollution in this city, is heavy on mobile sources. In Tabriz, however, statistics show that the share of mobile sources in air pollution is 60 per cent and the share of fixed sources is 40 per cent.

What is the pollution level in Tabriz?

According to figures released in 2019, Tabriz met the WHO target figure for PM2.5 of 10 µg/m³ or less for four consecutive months from March. July and August showed “Good” quality air with figures between 10 and 12 µg/m³. “Moderate” quality air was recorded for the remaining 6 months with figures between 12.1 and 35.4 µg/m³. There has been a small decline in air quality when compared with the previous year. In 2018 the figure was 12.2 µg/m³ whereas 2019 saw a figure of 13.2 µg/m³.

Is air pollution in Tabriz getting better or worse?

There are some light and heavy industries located on the North-western, Western, and South-western sides of the city. Industries such as oil refineries, thermal power plants, and petrochemical complexes are located on the South-western side, while a cement factory is situated on the North-western part of the city. In recent years, because of the development of industries and also the increase in the number of vehicles in urban areas, Tabriz has been faced with serious air pollution problems, especially in the winter season. In addition, air pollution in Tabriz is mostly under the influence of atmospheric thermal inversion in colder seasons and especially during the Middle East dust storm (originating from Iraq) in the warm season exacerbated the air pollution in this area.

The annual trend of PM10, PM2.5 and sulphur dioxide is decreasing whilst concentrations of nitrogen dioxide, nitrous oxide and carbon monoxide are increasing but was almost constant for ozone during the study period. During some of the studied days for PM10, PM2.5 and sulphur dioxide levels were exceeded greater than the WHO recommended levels.

The World Health Organisation (WHO) had in 2018 put Tehran in the category of ‘most polluted cities in the world but 2020 has been worse, according to government officials and environmentalists, with the AQI touching a record high not only in Tehran but also in other major cities such as Tabriz, Isfahan and Mashhad.

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

It has been suggested that industrial units who knowingly cause pollution should pay 1 per cent of their sales figures as a fine. This money could be used to develop green areas within the city, especially the planting of native trees.

Heavily polluting industries should retrofit their chimneys with filters and other devices to prevent harmful release into the atmosphere.

A more efficient means of public transport could alleviate the need for private vehicles in the city which would reduce pollution. The quality of fuel available should be at a premium with cheaper, higher sulphur content fuels banned.

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

Air pollution is the fourth leading cause of premature death after high blood pressure, smoking and malnutrition worldwide: Air pollution is also the second leading cause of death due to non-communicable diseases after smoking.

Adolescents, children under 14 years, people over 65, pregnant women, people with underlying diseases and cardiovascular, respiratory, metabolic problems such as diabetes, workers and these include people who work outdoors, especially those involved in strenuous activities, those in poor economic conditions such as the homeless and those who do not have access to adequate health care.

Young healthy people can experience health problems from polluted air including respiratory irritation or breathing difficulties during exercise or outdoor activities. The actual risk of adverse effects depends on the current health status of the individual, the pollutant type and concentration, and the length of the exposure to the polluted air. Extremely high levels of air pollution as often seen in Tabriz can cause immediate effects.

It was estimated that attributable proportions due to long-term exposure to PM10 were between 7.9 and 28.7 per cent for post-neonatal infant mortality and between 20.7 and 61.5 per cent for incidences of chronic bronchitis in adults. Long-term exposure to PM2.5 was attributed to about 11.8 per cent from all-causes, 34.6 per cent from ischemic heart disease, 26.7 per cent from stroke, 23.4 per cent from chronic obstructive pulmonary disease, 24.2 per cent from acute lower respiratory infection, and 16.5 per cent from lung cancer mortalities.

Even short-term exposure can lead to aggravated lung diseases and bring on asthma attacks and acute bronchitis. It increases the body’s chances of succumbing to respiratory diseases and infections. For those with pre-existing heart problems, it can cause a heart attack.

Even temporary symptoms can be annoying such as coughing, tightness in the chest and shortness of breath.