Air pollution in Istanbul increased by 11% in August compared with the same month last year, according to a study by Istanbul Technical University (ITU).
The study, conducted by Dr. Hüseyin Toros, head of the Department of Climate Science and Meteorological Engineering at ITU’s Faculty of Aeronautics and Astronautics, examined PM10, or particulate matter consisting of tiny airborne particles 10 micrometers or smaller, recorded across the city in August 2025 and August 2026.
Data from air quality monitoring stations operated by the Ministry of Environment, Urbanization and Climate Change and Istanbul Metropolitan Municipality (IBB) were analyzed.
The average PM10 concentration recorded at 26 monitoring stations across Istanbul rose to 31.9 micrograms per cubic meter in August 2026, up from 28.87 micrograms per cubic meter in August 2025.
PM10 pollution increased at 17 of the 26 stations, while levels decreased at nine.
The highest PM10 concentration was recorded at Sultangazi 1, at 53.06, followed by Sultangazi 2 at 51.26 and Tuzla at 44.28.
Sarıyer recorded the largest year-on-year increase, with PM10 pollution rising 120.05%, from 15.45 in August 2025 to 33.99 this August.
Kumköy followed with a 95.29% increase, while Arnavutköy recorded a 70.04% rise.
PM10 concentrations also increased by 57.45% in Sultangazi 2 and 48.58% in Sultangazi 1.
Meanwhile, Yenibosna recorded the largest decline, with PM10 pollution falling 30.89%, followed by Bağcılar at 23.77% and Maslak at 21.82%.
Toros said meteorological conditions played an important role in the increase in particulate matter concentrations in Istanbul in August.
He said prolonged hot, dry and atmospherically stable conditions, particularly during the second half of the month, contributed to the deterioration in air quality.
“Air quality in Istanbul in August 2026 was more unfavorable than in August 2025,” Toros said, attributing the change particularly to prolonged hot and dry conditions and greater atmospheric stability.
He explained that weaker winds and reduced atmospheric mixing lowered the boundary-layer height and the city’s capacity to disperse pollutants.
Limited rainfall and a lack of strong convective systems also made it more difficult for pollutants to be removed from the atmosphere, he added.
Toros noted that measurements varied considerably between stations, with pollution increasing in some areas while declining in others, showing that both local conditions and meteorological factors influence air quality.
He stressed that air pollution should be monitored more closely during periods of weak winds, limited rainfall and increased atmospheric stability, when pollutants are more likely to accumulate in the city.
