Hospital admissions in Istanbul increase during periods of high air pollution, with older people among the groups most affected, according to a study by Istanbul Technical University’s (ITU) Eurasia Institute of Earth Sciences.

The study, led by ITU researcher Özkan Çapraz, examined the relationship between air pollution levels and hospital admissions in Istanbul by comparing pollution measurements with health data from different periods.

Researchers analyzed approximately 3.94 million hospital admissions between 2013 and 2017 involving asthma, acute bronchitis and chronic obstructive pulmonary disease (COPD).

The findings show a significant relationship between air pollution and hospital admissions for all three respiratory conditions. Nitrogen dioxide and fine particulate matter were among the pollutants with the strongest effects.

"According to our study, hospital admissions increase during periods when air pollution is high,” Çapraz said.

He said pollution from human activities, particularly vehicle exhaust, has a stronger impact on health than some natural sources.

Older people face higher risks

The study separately examined the effects of air pollution on children, adults and people aged 65 and over.

The findings show that older people are particularly vulnerable to elevated pollution levels, while children and people with respiratory conditions such as asthma and COPD also face greater risks.

Çapraz said the health effects of pollution do not always appear immediately.

"For example, the effects can emerge several days after a day of high air pollution. This is called a delayed effect,” he said.

He urged vulnerable groups to limit outdoor activities on days when pollution levels are high.

Particulate matter and nitrogen oxides reach particularly high levels in Istanbul during the winter, according to the research. Autumn and spring follow, while pollution episodes that exceed threshold levels become less frequent during the summer.

The study also examined ground-level ozone, which can irritate the respiratory system and pose a particular risk to children, older people, asthma patients and those who exercise outdoors.

Çapraz said fine particulate matter can penetrate deep into the lungs because of its small size and trigger respiratory conditions including asthma and COPD.

He also noted that areas with heavy traffic, domestic pollution and industrial activity face greater air pollution risks.

Çapraz identified vehicle traffic as one of the major sources of air pollution in Istanbul and said switching from gasoline-powered vehicles to hybrid or electric vehicles could help reduce pollution.

He also recommended replacing coal and wood with natural gas for heating, saying this could have a positive effect on air quality.

Industrial facilities should also be located away from residential areas as much as possible, he said.