Street level air pollution in Istanbul

Air pollution monitoring as a tool for evaluation of urban projects

Edin Golubovic
airqoon
8 min readDec 14, 2018

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Galata tower Istanbul (picture by Rohan Reddy)

Background

By 2050, population increase will result in 68% of the world’s population living in urban areas. More people living in cities will inevitably cause increases in anthropogenic emissions due to traffic, industrialization and energy use. According to the World Health Organization, the effects of air pollution cause about 7 million worldwide premature deaths every year. Most of the health risks are associated with particulate matter of less than 10 μm (PM10) and 2.5 μm (PM2.5) in diameter. When inhaled PM penetrates deep into lungs and enters the bloodstream causing problems to cardiovascular and respiratory systems.

Recently, the idea of a Smart City was put forward to tackle challenges arising from massive urbanization. One of the essential features of a future Smart City is high resolution air pollution mapping. In order to take any step in the direction of reducing adverse health effects, air pollution levels need to be monitored and understood. To this end, a network of geographically distributed pollution monitors can provide an accurate picture for air pollution levels and overall citizen exposure to the pollutants.

Continuous monitoring of pollutants in Smart Cities is done by utilization of modern air pollution monitoring devices. With the advent of IoT, cost effective sensors, connectivity and Cloud technologies, air pollution measurement can now be done for a fraction of the cost of traditional monitoring systems. This allows the coverage of a geographic area by a number of monitoring stations leading to high-resolution air pollution data.

Among other uses, high-resolution air pollution data can be used to determine the requirements of urban projects before they are implemented, and their effectiveness after implementation. Urban projects such as, traffic re-routing, pedestrianization, emission control programs, etc., usually require quantitative metrics to determine their effectiveness with respect to a variety of factors. One of those factors is resulting reduction of air pollution in regions of the city.

In January 2018, we embarked on a journey with Istanbul’s Fatih municipality to monitor and understand air pollution levels along busy streets in Istanbul’s historic peninsula. A peninsula which is a UNESCO World Heritage Site for its historic and cultural importance. The historic peninsula hosts more than 2.5 million daily visitors and has nearly half a million full-time residents. In the past, many pedestrianization and traffic re-routing projects helped minimize human exposure to transportation-related air pollution. Our endeavor involves understanding the effect of pedestrianization of Ordu St. and adjoining streets on the air pollution levels, as part of the municipality’s latest urban project.

Region of interest on Istanbul’s historic peninsula — Ordu St. and adjoining streets with several popular squares

Challenge

Air pollution in the city has a complex dynamic that is dependent on the amount/location of pollution, source-type, weather conditions, urban topography, traffic routes and other human factors. Such a complex air pollution dynamic makes it a difficult situation to model and manage without proper monitoring mechanisms. Nowadays, air pollution monitoring is done on specially identified sites inside the city. Equipment utilized for this goal is inadequate for solving the severity of the air pollution problem and suffers several major disadvantages, namely:

  • high capital and operating costs
  • difficult maintenance
  • poor spatio-temporal resolution
  • poor data availability (frequent outages)

The main challenge of this project is associated with the generation of a dynamic, street-level, air pollution map in the region of interest including Ordu St. and adjoining streets by utilizing a more efficient air pollution management solution. As part of a larger project dealing with the pedestrianization, it is necessary to determine and evaluate the current state of air pollution at the street level. The obtained air pollution map, before and after pedestrianization, will primarily serve as the evaluation metric of the change in pollution due to this urban project. The secondary goal of the project will be to provide air quality information to the general public through a municipal citizen portal. The tertiary goal is to provide long-term air pollution trend data for future use in scientific research.

Solution

In line with the Smart City vision, a new generation of connectivity-enabled, low cost monitoring stations can be utilized for city-wide air pollution monitoring. With a large number of air pollution monitoring stations installed around the city, the desired high-resolution spatio-temporal map of pollution can be easily obtained. The dynamic air pollution map can then be used for public, industry or government goals such as; compliance with air quality standards, smart traffic re-routing, warning systems for sensitive groups of society, identifying of pollution hotspots inside the city, and urban project evaluation etc.

For the realization of this project we utilized Airqoon.

Airqoon is a fully-fledged hyperlocal air pollution management solution that enables monitoring, visualization and understanding of location based air pollution data in real-time.

Hyperlocal air pollution management value chain

Monitoring of air pollution is done using internet-connected miniature sensor units that utilize state-of-the-art sensing technology. Air pollution data, collected by sensor units, is visualized in a coherent and clear manner using advanced web and mobile tools. Real-time and historic air pollution data is analyzed using machine learning algorithms to discover hidden insights in data. Based on the meaningful patterns in air pollution data, management goals are defined and case-specific actions can then be taken. Airqoon can be used to manage air pollution levels at indoor or outdoor locations such as streets, schools, hospitals, factory floors, campuses and office buildings.

Airqoon solution components

Implementation

Airqoon sensor units provide air pollution data in real time. They are equipped with particulate matter (PM2.5 & PM10), temperature and humidity sensors. Airqoon sensor units are compact in size, easy to deploy and maintain, and powered by a combination of batteries and solar energy which makes them an ideal choice for Smart City deployments. Sensor units deployed at the regions of interest on the peninsula are shown below.

Deployed air pollution sensors

These sensors were installed at 5 strategic locations as shown on the map below. Such distribution of the sensor allows for air pollution monitoring at three possible pollution hotspots (1,3,5) and two places at the inner street areas (2,4). Sensor unit “1” is located near the busy intersection where there is a lot of daily traffic. The sensor unit “5” is located near the busies tourist square in the entire city. The sensor “3” is located near a busy bus stop and Grand Bazaar, the oldest covered market in the world. The other two sensor units monitor air pollution in the inner street areas. Such distribution of the sensors can provide an accurate picture of street-level pollution in real-time.

Air pollution sensors locations on peninsula

Air pollution data is collected in a periodic manner and real time data is visualized on the web dashboards. Air pollution data is stored and further processed to obtain 24-hour analytics. Using the same system, data is shown to citizens through the municipality portal.

Results so far

Collected data at the strategic locations on the peninsula indicate several phenomena worth taking into consideration when planning a pedestrianization project. To demonstrate the hidden insights in data we have compiled some results and shown them below. These are just partial results, if you are interested to know more please contact us. Average hourly PM2.5 concentrations were computed with respect to the days of the week for every hour of the day, e.g., results marked “Monday” stand for accumulated metrics for every hour of every Monday ever since we started project. Our goal here is to make a comparison of air pollution levels for different days of the week. Data are shown in the form of box plots in the figures below.

Comparison of average concentrations of PM2.5 at the farthest east (right) and farthest west (left) points of the street

Looking at the results, we can see that Fridays are the least polluted days on Istanbul’s historic peninsula. We can also see that at the sensor location “5”, the Sultanahmet square, weekends are relatively more polluted than at the other spots. This can be explained from two standpoints, first, the square has much more “people traffic” during the weekends, and second, traffic re-routing that occurs during the weekend may adversely affect this area. The measurements at the sensor location “1”, at the beginning of Ordu St., show relatively less pollution on Sundays when compared weekdays, which may be due to this street being closed to traffic on Sundays.

These are just partial results, if you are interested to know more details about insights produced as a result of data analysis please contact us and we will share them with you.

Involved parties

Inovatink

Inovatink is Istanbul based technology startup that develops IoT products and services. Inovatink’s products and services help improve human lives and stimulate business activity in disruptive manner. Airqoon, the solution utilized in this project is one of the solutions offered by Inovatink for hyperlocal air pollution management. Airqoon provides data-driven and actionable environmental intelligence to enterprises, cities and institutions that manage air quality as a part of their value creation processes.

Fatih Municipality

Fatih Municipality invests it’s resources in people, city and information. It is continuously improving the quality of the services it provides to its citizens, preventing internal migration while transforming the district of Fatih into livable area. Municipal services provide social, environmental and economic sustainability through principles of governance such as transparency, accountability, participation, the rule of law, efficiency and equality.

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Edin Golubovic
airqoon
Editor for

Senior Embedded Software Engineer @EnOcean. Interested in #IoT, #renewableenergy, #machinelearning, #wearables, #smartcity.