A paradigm shift: Low-cost sensors for effective air quality monitoring and management in developing countries

This study gives an overview of the air quality monitoring challenges faced by South Asian countries, with a specific focus on Pakistan, and explores the potential application of low-cost sensors (LCS) to address these issues. Currently, 89% of the 4.2 million premature global deaths attributable to ambient air pollution occur in low- and middle-income countries, underscoring the urgent need for improved monitoring and abatement measures. In Pakistan, these challenges result in significant public health and economic consequences due to institutional and financial constraints, limited data availability, and transboundary pollution. The situation is exacerbated by the absence of an effective air quality regulatory network. This study proposes a shift by establishing a hybrid monitoring network that integrates conventional regulatory instruments with LCS. The current PM_2.5 pollution scenario in major Pakistani cities is analyzed using data from 61 LCSs installed nationwide, with one TSI BlueSky sensor validated against a regulatory BAM (Beta Attenuation Monitor) in Chakwal. Results show that the unadjusted BlueSky values demonstrate a strong correlation (Pearson correlation 0.85) with the reference BAM instrument, with acceptable error margins (NRMSE and NMAE of 8% and 6%, respectively), indicating the sensor's potential for reliable monitoring. Though adjusted values aligned better, the analysis focuses on unadjusted data for broader applicability. These findings suggest that combining LCSs with advanced data analytics can serve as a technically and economically viable solution for accurate air quality monitoring and effective management in Pakistan and other developing countries facing similar high PM_2.5 concentrations. This paradigm shift enhances monitoring capabilities and supports informed policy-making and public health initiatives.