Qualité de l’air à Hamedan

What is the level of air pollution in Hamedan city?

Hamedan is the capital city of Hamadan Province of Iran. According to a census conducted in 2019, Hamedan had an estimated population of approximately 783,300 people. The majority of which identify as being ethnic Persians. It is believed to be the oldest Iranian city and is located 360 kilometres south west of Tehran in the foothills of the Alvand Mountains.

In the third quarter of 2021, Hamedan was experiencing a period of “Moderate” air quality with a US AQI reading of 52. This United States Air Quality Index figure is calculated by collating the recorded levels of six of the most prolific air pollutants. These may include, both diameters of PM (PM10, PM2.5), nitrogen dioxide, sulphur dioxide, ozone and carbon monoxide. If figures are not available for all six, a level can still be calculated by using what information there is. It can then be used as a metric when comparing one city with another, anywhere in the world. For Hamedan, both sizes of the PM pollutant were measured which were PM2.5 - 12.1 µg/m³ and PM10 - 57 µg/m³. With this level of PM2.5, it is just higher than the recommended level of 10 µg/m³ as suggested by the World Health Organisation (WHO) as being an acceptable level. Although no amount of air pollution should be considered to be safe.

With pollution at this level, the given advice would be to remain indoors if possible and close windows and doors to prevent the ingress of more dirty air. Those who are more sensitive to air quality should avoid outdoor activities until the situation improves. If it is unavoidable, then a good quality face mask should be worn at all times of exposure. There is a downloadable app available from AirVisual for all mobile operating systems which has real-time levels of air quality at the touch of a button.

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

Air quality can be very volatile and can change very quickly. It can be affected by many variables such as meteorological conditions and even the local topography.

Looking back at the figures for 2020 as published by IQAir.com, it can easily be seen that the quality of air remained in the “Moderate” category for the full 12 months. To fall into this category, figures need to be between 12.1 and 35.4 µg/m³. The month with the best quality was March with a figure of 13.5 µg/m³ and the worst air quality was found during May with a figure of 29.3 µg/m³.

Records pertaining to air quality were first kept in 2019 when an average annual figure of 21.8 µg/m³ was recorded. This improved in the following year when 2020 revealed a figure of 18.8 µg/m³. This reading may have been affected by the COVID-19 situation as many vehicles were no longer in daily use as staff were encouraged to work from home in an attempt to slow the spread of the virus. Many factories and non-essential production units were also required to close which removed their emissions from the atmosphere.

Where does the polluted air come from in Hamedan?

According to field studies, one of the major causes of air pollution is the use of motor vehicles, cars and gas-powered vehicles, heavy-duty trucks and also motorbikes.

Natural factors such as cold weather and temperature inversion are effective on pollution, and rain and wind can have a significant effect on reducing air pollution.

Just recently, air pollution in the province has not been in a critical condition and it is not true that Hamedan was recently introduced as the most polluted city in the country, which could be due to an air monitoring device in Hamedan that measures specific conditions so that air pollution may be measured over a 24-hour period and at a pivotal point.

Can anything be done to improve air quality in Hamedan?

It is possible to use less private and single-passenger cars and use public vehicles and technical inspection of cars so that we do not see this amount of pollution in the country and the province.

The head of air pollution control at Hamadan University of Medical Sciences stressed that the technical inspection of cars in Hamadan should be seriously pursued, adding: "Unfortunately, this issue is not considered in Hamadan, while in Tehran, a car that does not have a technical inspection is automatically fined every day. He also stated that gasoline burning of intercity buses is one of the important issues: many buses in Hamedan are very polluting because they use diesel as a form of fuel which has a higher sulphur content than gasoline.

He pointed out that sometimes these buses keep their engine running for a long time in the city whilst waiting for passengers, and said: "Keeping the bus engine running is also a cause of pollution, and because they are located in the city centre, the pollution will definitely spread to residential areas. As far as possible, these vehicles should use natural gas because the pollution of this type of fuel is less than gasoline or diesel.

What are the detrimental effects on the human body caused by polluted air in Hamedan?

According to doctors, specialists and community health professionals, the phenomenon of air pollution has effects on internal organs such as the cardiovascular and respiratory systems, as well as external organs such as the eyes and skin that are directly exposed to air pollution. It is destructive.

The occurrence of chronic diseases such as asthma and skin allergies and sometimes incurable diseases such as cancer are among the destructive and irreversible effects of air pollution on the health of society.

Air pollution and fine particles of less than 2.5 microns can cause abnormal heartbeats and disturb the heartbeat by disrupting the order of heart function.

In some countries, the number of people who die due to air pollution is higher than the number of victims of traffic accidents. These deaths are specifically related to diseases such as asthma, bronchitis, shortness of breath, heart attacks and various respiratory allergies. Air pollution can have long-term and short-term harmful effects on human health. The impact of air pollution on different people varies.

Patients who are at high risk for heart attack or stroke are more likely to be admitted on hot, dry days when air pollution is high and there are high levels of carbon monoxide in the air. One of the reasons for this phenomenon is the irreversible binding of carbon monoxide to haemoglobin in the blood, which reduces the transport of oxygen in the blood. The occurrence of such a process in patients is very dangerous and can lead to exacerbation of the patient’s condition.