Air pollution in Istanbul declined by 8% in May compared to the same period last year, according to a study conducted by researchers at Istanbul Technical University (ITU).
The research, led by Hüseyin Toros, head of the Climate Science and Meteorological Engineering Department at ITU's Faculty of Aeronautics and Astronautics, analyzed particulate matter (PM10) measurements recorded across the city during May 2025 and May 2026.
The study examined data collected from 26 air quality monitoring stations operated by the Ministry of Environment, Urbanization and Climate Change and Istanbul Metropolitan Municipality.
The study found that the average concentration of PM10, a type of airborne particulate pollution, fell from 34 micrograms per cubic meter in May 2025 to 31.2 micrograms per cubic meter in May 2026.
Among the monitoring stations, the highest particulate matter concentrations in May were recorded at Sultangazi 3, Sultangazi 2 and Tuzla, while the lowest levels were measured at Sultangazi 1, Büyükada and Alibeyköy.
Researchers found that air pollution levels decreased at 17 of the city's monitoring stations and increased at 9 others. The largest increase was recorded in Sarıyer, where PM10 levels rose by more than 90% compared to the previous year. Arnavutköy followed with an increase of nearly 80%.
Meanwhile, the sharpest decline was observed at the Sultangazi 1 station, where particulate matter concentrations dropped by nearly 59%. Significant decreases were also recorded in Esenler and Ümraniye.
According to the study, favorable weather conditions played an important role in reducing pollution levels across the city. Increased rainfall helped remove airborne pollutants, contributing to cleaner air during the month.
Meteorological data showed that precipitation across the Marmara Region rose by approximately 60% compared to the previous year. Researchers noted that the higher amount of rainfall experienced in Istanbul during May helped improve air quality by washing particulate matter from the atmosphere.
Speaking about the findings, Toros said Istanbul's large population, intense traffic and industrial activities continue to be major sources of air pollution.
The city is home to around 6 million registered vehicles, with heavy traffic occurring throughout much of the day on major roads connecting the European and Asian sides of Istanbul, he noted.
Toros explained that particulate matter pollution is generated by several factors, including dust lifted by vehicle movement, industrial emissions and pollutants transported from other regions through atmospheric circulation.
He emphasized that maintaining and improving air quality remains essential for public health, particularly in a densely populated metropolitan area such as Istanbul.
Toros also encouraged residents to monitor air quality data published by government agencies and local authorities and to contribute to efforts aimed at reducing pollution in their communities.
While Istanbul's average PM10 levels remain below Europe's daily air quality limit of 50 micrograms per cubic meter, he said further reductions would bring additional health benefits and improve the quality of life for residents across the city.
