A kit of low-cost sensors for measurements of dust-PM in arid urban environments

Dust storms (DSs) are a common phenomenon in many areas worldwide and a natural source for particulate matter (PM) in the atmosphere. Yet the knowledge about the impacts of DSs on the spatio-temporal distributions of PM in urban environments is limited. Air pollutants are regularly monitored by environmental stations in very few locations within large cities. This limits our ability to assess the exposure to PM in space and time. A kit of low-cost sensors (LCS) was developed in our lab (BGSense) to measure air-quality and meteorological data in outdoor and indoor environments, with high spatial and temporal resolutions. The BGSense is designed to be used in stationary or mobile modes of measurement networks in the city. Data from the BGSense sensors are being compared to the reference instruments of the environmental station, located in an arid urban environment. The sensors are tested under various meteorological conditions, including DSs (1-hour average PM₁₀ concentrations < 100 µg m^-3), in which hourly concentrations can reach ~2000 µg m^-3. The calibration process shows strong correlations (R²=0.9) between the reference instruments and the BGSense for both air temperature and relative humidity. The PM data of BGSense vs. TEOM are well correlated for PM₁₀ in DS (R²=0.8) and in non-DS (R²=0.7) time periods. A similar trend is obtained also for PM_2.5. Preliminary measurements, done simultaneously with BGSense kits in several locations around the university campus, demonstrate variations in PM₁₀ concentrations in space and time. The BGSense has the potential to provide high-resolution data to explore the dust-PM distribution and health exposure risk in urban environments.