Real time particulate pollution monitoring in Coimbatore using customized commodity monitor
Creators: name: KA, Nishadh
name: Mohanraj R
name: PA, Azeez
Publisher: name: Zenodo
Year: 2019

description: Particulate pollution and its resultant health effects are considered one of the large health problems across the world. Particulate pollutants (or suspended Particulate Matter - PM) are particles with small aerodynamic diameter. The size distribution of the PM is one crucial aspect of monitoring their environmental and health implications. Hence, PM is monitored primarily with the objective of finding the size distribution and concentration. It is commonly monitored in terms of standard measures in two size bins of PM<sub>2.5</sub> and PM<sub>10</sub>, by manual air filtration, optical methods or by continuous and integrated instruments determining mass concentration. However, high investment and running cost for automatic real-time instruments largely hinders their wider deployment. Consequently, particle counters are being widely tried for their explicit low cost, ease of use and very short response time in measuring particle concentration in the ambient air. In this context, the current study aims to evaluate the effectiveness of a customized particulate matter monitor for Indian situation. It is based on a low-cost commodity monitor, fabricated with locally available open-source hardware, tools, and expertise. DylosTM model number DC1100 is a patented indoor air quality monitor commercialized by Dylos Corporation (USA). To customize DylosTM into a real-time ambient particulate monitor, it was equipped with data collection, storage, and real-time data communication setup. For field deployment, the whole setup (monitor with data storage and communication) was housed in an all-weather steel box, specially designed for the purpose. To evaluate the functionality of the developed/customized real-time PM monitor, four units were deployed in various parts of Coimbatore city. To assess the validity of data from the units, collocation samplings were carried out concurrent with industrially calibrated portable particulate monitor MetoneTM Aerocet-531S. To assess the relationship/collinearity across the readings from collocated monitors, plots and adjusted R<sup>2</sup> values of linear regression between pair’s of hourly average samples were used. Four locations in Coimbatore urban region were selected for ambient testing and data validation of the developed monitor. The customized monitor development, for the loosely coupled power source and single board computer, called for intermittent manual interventions. That suggests design overhaul replacing with embedded boards, and stable connectivity with the battery power source. Python programming language based scripts were used for real-time data communication. Ambient testing reflected the general trend and stations’ pollution profile. The system effectiveness of real-time particulate monitor was also assessed in terms of system persistence and data communication. It is observed that the monitor was effective in continuous operation for data collection, storage, and real-time communication and long-duration monitor operation. Collocation sampling was used for data validation and it is found that the developed monitor is correlating well with the industrially calibrated monitor. However, the variations in agreement at different periods indicate the requirement of continuous and more robust calibration of the monitor.
description: Presentation in International Conference on Air Pollution and Monitoring (ICAM-2019), School of Environmental Sciences, Mahatma Gandhi University, Kottayam, India, 8-11 March 2019.