Examining Air Quality in School Districs of Istanbul- 2020 & 2021
It has been revealed that exposure to air pollution has many adverse effects on human health, especially considering its damage on the respiratory and cardiovascular systems (Rivas et al., 2014). However, few studies have focused on the relation of air pollution and brain development.
“Evidence obtained from experimental studies in animals suggests that outdoor air pollution may play a major role in the inflammation of the central nervous system during sensitive periods (such as childhood) and consequently in behaviour and school performance. A growing body of research, albeit limited, from epidemiological studies indicates that exposure to air pollution may be associated with an increased risk of neurodevelopmental disorders and cognitive impairments.” (Rivas et al., 2014)
Children spend most of their days at school. The academic year in Turkey lasts approximately 180 days with an average of 30 hours per week. For this reason, the choice of school location is one of the most important factors for children’s health. However, many schools are located near busy roads, which increases traffic-related air pollution in schools and poses higher health risks due to atmospheric pollutants (Sunyer et al., 2015). In addition, children are considered as a vulnerable population particularly due to their physiological and behavioral characteristics. Due to their high levels of physical activity, they are exposed to more air pollutants than adults (Trasande & Thurston, 2005).
Contaminant concentrations are usually highest at the first meter above ground level and decrease with distance from the road (including altitude). Because of their short stature (especially in kindergarten and primary school), school-going children may be exposed to airborne dust and exhaust gases 60% more than adults (Şahin et al., 2021).
Monitoring of NO2 and particulate matter is important to understand traffic and industry related emissions in school districts. Studies show that prolonged exposure to NO2 increases susceptibility to respiratory infections and can cause permanent structural changes in the lungs. Even short-term exposure in children can increase the risk of a respiratory disease. When exposed to Particulate Matters (PMs), children with a lung disease history may not be able to breathe properly and symptoms such as coughing and shortness of breath may occur (URL1).
One of the main characteristics of Istanbul is its high population density with approximately 16 million inhabitants. Thus, people living in Istanbul are highly exposed to vehicle exhaust and non-exhaust substance emissions. Fine particulate emissions related to traffic comprise about 29% of the total fine particles in Istanbul (Şahin et al., 2020). In 2021, Istanbul’s urban traffic fleet is characterized by a large number of cars (68.5%); motorcycles (8.6%) and heavy vehicles (3%) (TURKSTAT, 2020). In addition, Istanbul is considered one of the most important ports in Europe and receives the largest number of cargo ships in Turkey. This creates an additional source of atmospheric pollutants that are very often carried throughout the city by the sea breeze during the day.
Within the scope of this study, the air quality in 8 different school districsts in Istanbul was examined. Selected regions were determined according to four criteria: Those close to a busy highway, namely D-100 Highway (Yenibosna, Selimiye), those located near the roads with intense urban use (Maslak, Kandilli), and those located in the focal point where mixed use is intense (Aksaray, Uskudar) and those located near industrial facilities (Basaksehir, Tuzla).
Air pollution data is collected by monitoring stations close to the selected regions. These stations are maintained by the Ministry of Environment and Urbanization, the Istanbul Metropolitan Municipality and Airqoon. Air quality of school districts in Aksaray, Basaksehir, Kandilli, Maslak, Selimiye, Tuzla, Uskudar and Yenibosna regions between January-March 2020 and 2021 was examined. The data recorded by these stations were downloaded from the website of the Ministry of Environment and Urbanization (URL2) and from Airqoon’s data recording system. The main goal of this study is to investigate whether the air quality is suitable for children’s health according to the location of the schools where children spend most of the day.
There are a total of 20 schools in the regions examined within the scope of the study. 4 of them are primary school, 8 of them are secondary school and 8 of them are high school. Approximately 2103, 3144, 671, 1850, 4141, 1347, 1634 and 1470 students receive education in schools located in Aksaray, Basaksehir, Kandilli, Maslak, Selimiye, Tuzla, Uskudar and Yenibosna districts, respectively (URL3).
Air Quality of Schools According to PM10 Values
Considering the PM10 (fine particles with an aerodynamic diameter of less than 10 µm) measurements collected by monitoing stations in January-February-March of 2020 and 2021, it was determined that the air pollution was the highest in Yenibosna in March 2020, with an average of 56 µg/m³.
As a result of the measurements made in January 2020, the 24-hour PM10 50 µg/m³ limit value determined according to the Outdoor Air Quality Management Regulation prepared by the Ministry of Environment and Urbanization (T.R. Environment and Urban Ministry, 2008) is 10 days in Yenibosna, 5 days in Basaksehir and Tuzla, 7 days in Aksaray and it was determined that 2 days in Uskudar, Selimiye and Kandilli and 1 days in Maslak were exceeded. Air quality is moderate these days, risky for human health. PM10 was measured at 103.6 µg/m³ in Aksaray on Saturday, January 11th.
In February 2020, while the air quality of Yenibosna, Aksaray, Selimiye and Uskudar were improved; there was a decrease in Basaksehir, Maslak and Tuzla. While it is moderate for 4 days in Basaksehir and 8 days in Tuzla; it was observed that the air quality in Selimiye was moderate for only 1 day during the whole month. It has been determined that the air quality in March is worse than in January and February 2020. Air quality was found to be moderate for 12 days in Yenibosna and Basaksehir, 9 days in Tuzla, 8 days in Aksaray and Kandilli, 5 days in Uskudar, and 4 days in Selimiye and Maslak. At the same time, it was observed that the air quality was sensitive and dangerous for the health of children for 3 days in Yenibosna.
While PM10 in January-February-March 2021 is increased compared to 2020 in Maslak and Kandilli regions; it showed a decrease in Yenibosna and Selimiye regions and it was determined that the air quality of Selimiye was always good in all months examined in 2021. In January 2021, air quality was moderate for 10 days in Tuzla, 7 days in Basaksehir, 6 days in Yenibosna and Kandilli, 5 days in Aksaray, 3 days in Maslak, and 1 day in Uskudar; air quality was sensitive for 1 day in Basaksehir. In February 2021, air quality decreased in all regions. PM10 was measured at 106.4 µg/m³ in Yenibosna on Tuesday, February 23. In March 2021, while the air quality was good throughout the month in Selimiye and Uskudar; it was determined that the air quality was moderate for 9 days in Basaksehir, 7 days in Yenibosna, Tuzla and Kandilli, and 4 days in Aksaray and Maslak.
It has been seen that PM10 values are high in Yenibosna region, where schools are close to the D-100 Highway, and in Tuzla and Basaksehir regions, which are close to industrial areas. It is thought that the high PM10 values in these regions may be caused by road dust (non-exhaust emissions from pavement, tire and brake wear and re-suspension of accumulated material on the road) and industrial emissions.
There were insufficiencies in the monitoring station data in the time period of the research. Due to incomplete data entry of Tuzla and Kandilli in January and March 2020, and Maslak in March 2020 air quality could not be examined in this period and therefore the atmospheric pollutants that constitute the health of the children here could not be followed. In 2021, there was a lot of missing data in Maslak in February and March.
By looking at the PM10 measurements of the regions on weekdays and weekends, it was investigated whether the activities to be held at the weekend were appropriate or not. Looking at the PM10 of 8 regions in January 2020, it was seen that the PM10 was higher at the weekend in all regions except Tuzla. The highest pollution was measured in Aksaray and Yenibosna at the weekend.
By examining the hourly PM10 data according to the school entrance time, lunch break and school exit hours of the regions, it was investigated in which time period children are exposed more to air pollution. According to the PM10 data of January 2020, it was determined that air pollution tended to increase during the lunch break in all regions except Uskudar. In Uskudar, on the other hand, pollution is higher at the time of entry to school in the morning.
When we look at the weekday and weekend PM10 of the regions in February 2020, it has been determined that weekday PM10 measurements are higher in all regions, unlike January 2020. Basaksehir, Tuzla and Yenibosna are the regions with the highest PM10 measurement.
When the hourly PM10 of the regions are examined; In Tuzla, on the other hand, PM10 measurements were always found to be risky for children’s health, except for the starting hours of primary school. Compared to January 2020, PM10 values are lower during the day in Aksaray and Yenibosna.
In March 2020, PM10 increased in Yenibosna and Tuzla compared to other months. In Selimiye and Uskudar, while the PM10 level was higher on weekdays than at the weekend; In Aksaray, Basaksehir, Kandilli, Maslak, Tuzla and Yenibosna, the PM10 level was higher at the weekend than during the week. Especially in Basaksehir, Tuzla and Yenibosna, weekends were not suitable for organizing activities at school.
In Yenibosna, where the PM10 measurements were the highest and risky in March 2020, the pollution was highest at the time of entry to school in the morning, and the PM10 level in the air during the lunch break was not suitable for children’s physical activity. In Aksaray and Selimiye, the pollution was highest at the time of entry to school in the morning; pollution was higher in Basaksehir, Kandilli, Maslak and Uskudar during the lunch hour.
In January 2021, the highest pollution was measured in Tuzla during the week. Compared to January 2020, PM10 measurements were increased in Basaksehir, Kandilli, Maslak and Tuzla. Except for Aksaray, PM10 levels were higher on weekdays than at weekends in all other regions.
In Basaksehir and Tuzla, where PM10 were the highest on weekdays, the PM10 was the highest during the lunch breaks of the schools due to this fact it was not suitable for students to spend their time in the school garden. PM10 values at all hours of the day in Kandilli, Selimiye and Maslak were suitable for children’s physical activities.
It was determined that there was an increase in the weekend PM10 of the regions in February 2021 compared to January. While Tuzla’s PM10 level on weekdays had the highest value this month; The PM10 value of Selimiye on weekdays was the lowest level.
When we look at the regions according to the hourly PM10 values, it can be said that the PM10 value is high in all hours except the morning entrance to the school in Basaksehir and therefore the air quality is low. In the same way, PM10 level is high and risky in Tuzla at all hours except the exit time of primary schools.
In March 2021, there was an increase in PM10 level over the weekend in the regions. It has been determined that schools in Maslak and Kandilli, which are located near busy roads, are exposed to more pollution this month. It is not appropriate to do activities in schools on the weekend.
When the hourly PM10 values in March 2021 are examined, while the PM10 was the highest during the lunch break in Basaksehir, Kandilli and Uskudar; in Aksaray, Selimiye, Tuzla and Yenibosna, the PM10 value was highest in the morning at school entry time. In Maslak, on the other hand, PM10 level has the highest value at the starting time of primary schools.
Air Quality of Schools According to NO2 Values
Monitoring NO2 is important to understand the level of traffic emissions. When the NO2 of the regions were examined within the scope of the study, it was observed that the NO2 values were high in the central regions where mixed use is intense (node) and in the regions close to D-100 Highway.
According to NO2, Selimiye, Yenibosna, Aksaray and Uskudar were the regions where the air quality is bad throughout the month. Air quality in Aksaray and Selimiye often reaches sensitive levels. While there was an increase in N02 value in Aksaray in 2021 compared to 2020; it was decreased in Yenibosna. Due to incomplete data entry in Tuzla in 2020 and Aksaray and Uskudar in 2021, air pollution could not be fully monitored.
According to the data obtained from the measurement results, it has been determined that the 1-hour average 200 µg/m3 threshold limit value determined by the WHO (URL4) in Aksaray, where the NO2 level is the highest, was exceeded 1 times in January 2020 and 5 times in March 2020. This limit value was exceeded 42 times in January 2021, 179 times in February, and 219 times in March.
Looking at the hourly NO2 values in February 2020 and 2021, it is seen that air pollution is high in Selimiye, Aksaray and Yenibosna regions, as in January. There was an increase in the NO2 level in Aksaray in 2021 and it poses a great risk for the health of children as it is at a sensitive level throughout the month. In Basaksehir, it was determined that the air quality was good throughout February 2020. Due to the lack of NO2 data for Maslak and Uskudar regions in 2021, a comparison with 2020 could not be made and air quality could not be examined.
As in other months, NO2 levels are high in Selimiye, Aksaray and Yenibosna regions in March. NO2 level is always good in Basaksehir in March 2020. However, it was determined that there was an increase in NO2 value in all regions, including Başakşehir, in 2021. Air pollution could not be monitored in Maslak region in March 2020 and 2021 due to incomplete data entry.
It can be said that the low NO2 values in Tuzla and Basaksehir, where PM10 values are high, and the air pollution in these regions are not caused by traffic but by industrial emissions. At Aksaray and Selimiye stations, which are close to traffic, the NO2 level is 2–3 times higher than the other stations.
When we look at the weekday and weekend values of NO2 in January 2020, it was seen that weekend NO2 values were higher than during the week in all regions except Tuzla, which could not be examined due to the lack of data. In Aksaray, Selimiye, Uskudar and Yenibosna, the NO2 level on weekdays and weekends is not suitable for children to perform their physical activities outside.
Looking at the hourly NO2 values of January, it has been determined that children are exposed to more pollution at the time of entry to school in Maslak, Uskudar and Yenibosna. In Aksaray and Selimiye, the NO2 level in all watches is not suitable for the health of children.
As in January, Aksaray and Selimiye are the regions with the highest NO2 levels in February 2020. However, the NO2 level on weekdays is higher in February than at the weekend, unlike January.
There was no difference in hourly NO2 level in February compared to January. While pollution is high every hour in Aksaray and Selimiye; Pollution is higher in the morning hours in Maslak, Tuzla, Uskudar and Yenibosna. At any time of the day in Basaksehir and Kandilli, NO2 levels are suitable for children’s health.
When we look at the weekday and weekend values of NO2 in March 2020, it has been determined that weekend NO2 is higher in all regions except Tuzla. There is no data for the month of March for the Maslak region. In Basaksehir and Kandilli regions, NO2 level does not pose a danger in terms of air pollution; NO2 level in other districts is risky for children’s health.
In March 2020, there was an increase in the NO2 level in Tuzla compared to January and February. NO2 levels are higher and risky in the morning hours in Selimiye, Tuzla, Uskudar and Yenibosna; In Kandilli and Basaksehir, the air quality is suitable with NO2 level at all hours.
When the NO2 values in January 2021 are examined, there has been an increase in the NO2 level in Aksaray compared to the other year. In Basaksehir and Kandilli, the NO2 level is very low. As for the Maslak region, there was no NO2 data, so no evaluation could be made. While NO2 levels on weekdays and weekends in Selimiye and Uskudar are risky for children’s health; In Tuzla and Yenibosna, it is risky only on weekdays.
Considering the hourly NO2 values in January 2021, the NO2 level increased in Aksaray compared to January-February-March of 2020; It was determined that NO2 levels were decreased in Basaksehir and Kandilli regions. While the NO2 level is higher in the morning hours in other months in Selimiye; NO2 level is higher at lunch break time in January 2021.
In February 2021, there was an increase in NO2 levels in all regions compared to January 2021. NO2 values in Aksaray, Selimiye, Tuzla and Yenibosna were not suitable for children’s outdoor physical activities.
In February 2021, it was observed that there was an increase in NO2 values in the evening school leaving time in all regions. In Selimiye, Tuzla and Yenibosna, the NO2 level was the highest in the morning when entering school; It was measured in Aksaray, Basaksehir and Kandilli in the evening, after school. NO2 data is available for Maslak and Uskudar.
In March 2021, it was determined that the NO2 level increased at the weekend compared to other months in the regions. Aksaray, Selimiye and Yenibosna are the areas with the highest NO2 air pollution, and the NO2 level is the same on weekdays and weekends. In the Maslak and Uskudar regions, air pollution in the region could not be determined due to the lack of data.
When the NO2 values in March 2021 are examined, it has been determined that the NO2 level is high at all hours in Aksaray and Selimiye, and at the time of entry to school in the morning in Tuzla and Yenibosna. In Basaksehir and Kandilli regions, the amount of NO2 is higher in the morning hours, however; It does not pose a problem for children’s health.
The air quality of the schools in 8 selected regions in Istanbul was examined daily, weekly and hourly according to the PM10 and NO2 data obtained from the air quality measurement stations. In line with the analyzed data, it has been determined that NO2 measurements are significantly high in Selimiye, Aksaray and Yenibosna stations, which are close to traffic. It has been determined that the schools in the regions are built on the sides of the main roads due to the ease of transportation, the school entrance gates are close to the road, and the intersections and bus stops are located around the school. This causes vehicle emissions to easily enter school buildings, including classrooms, and expose children to more NO2. In Tuzla and Basaksehir, it can be said that air pollution may be caused by the industries in this region due to the low NO2 levels and the very high PM10 values. It has been observed that children are less exposed to air pollution than other regions, since the study area in Kandilli and Uskudar is in a more urban background compared to other regions. Due to the large number of missing data, especially in Maslak, a desired examination on air quality could not be achieved.
In order to protect the future of our world and our children’s health, plans of school districts should be revisited with the guidance from environmental intelligence technologies. It is quite important to enhance the quality of life of our children by reducing the traffic in school districts via new age traffic monitoring and management systems and by increasing the supervision of industrial facilities. A clean air zone should be created around schools.For the health of our children, air pollution measurement stations should be placed in more school districts and air pollution should be monitored. In this regard, students, teachers, parents and school management should be encouraged to raise awareness and take necessary precautionary measures.
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URL1: https://havakalitesi.ibb.gov.tr/Icerik/bilgi/hava-kirleticileri The Istanbul Metropolitan Municipality, Pollutants and Health Effects. 10 August 2021.
URL2: https://sim.csb.gov.tr/STN/STN_Report/StationDataDownloadNew T.R. Environment and Urban Ministry, Air Quality Station Data Download. 1 August 2021.
URL3: https://www.meb.gov.tr/baglantilar/okullar/index.php T.R. Ministry of Education, Schools and Other Institutions. 10 August 2021.
URL4: https://www.who.int/news-room/fact-sheets/detail/ambient-(outdoor)-air-quality-and-health World Health Organization, Ambient (outdoor) Air Pollution. 17 August 2021.
