Investigation of Vertical Particulate Matter Distribution using Low-cost Sensors in Istanbul, Turkey

 Abstract — Particulate matter (PM 2.5 and PM 10 ), which is one of the most important pollutants in the atmosphere, has serious effects on both human health and the environment. Air quality monitoring stations may not accurately represent pollutant gradients in a city due to the large spatial variability of these pollutants in urban environments, especially for traffic-related air pollutants such as PM 2.5 . Recently, the use of Unmanned Aerial Vehicles (UAVs) in air quality applications is a new popular approach that is believed to overcome several limitations of existing methods. In this study, the vertical distribution of PM 2.5 and PM 10 pollutants and the variation of meteorological parameters including temperature, relative humidity, and pressure were investigated in an urban area of Istanbul using low-cost sensors mounted on a UAV. Three field experiments were conducted on August 20, August 25, and September 3, 2021 using two different laser PM sensors, GROVE HM3301 and NOVA SDS011. The data was collected every 10 meters, with a 30-second hover, ranging in height from ground level to 100 m and the results were averaged for each altitude. According to the GROVE HM3301 and NOVA SDS011 measurement results at 100 m, PM 10 concentrations decreased by about 15.5% and 9.4%, while PM 2.5 concentrations decreased by about 11.1% and 0.8%, respectively. The GROVE HM3301 PM 10 and PM 2.5 measurement concentrations were found to be closer to each other, and the NOVA SDS011 particle sensor provided more sensitive measurement results. All the peak PM 2.5 and PM 10 concentrations were found at the ground level except for the NOVA SDS011 PM 2.5 measurement results, where the maximum PM 2.5 concentration was observed at 80 m altitude. Temperature, pressure, and relative humidity were found to be negatively correlated with