Performance of Low-Cost Sensors in Measuring Particulate Matter Concentrations in Indoor and Outdoor Environments

Air pollution is one of the major causes of early death worldwide and is especially widespread in many low-and middle-income nations (LMICs). Preliminary monitoring networks, satellite retrievals of air-quality-relevant species, and air quality models show that in Asian countries, ambient fine particulate matter (PM) concentrations exceed World Health Organization guidelines, despite the fact that many areas generally remain unmonitored and understudied. The size of PM in the air and the ratio of fine to coarse PM determine the ability to affect the environment and health. Although better monitoring of the air quality levels is of prime importance, the costs involved in setting up monitoring stations are often a big hurdle. This study investigates the distribution and proportion of PM1, PM2.5, and PM10 at multiple locations in an educational institute in Goa. In addition to continuous monitoring using low-cost sensors (LCS), including PMS5003, PMS A003, PMS 7003, Winsen ZH 06, SPS 30, Novafitness SDS 011, and Honeywell HPMA, we have also attempted to compare the performance of these sensors with Alphasense OPC N3 at Indian Institute of Technology Goa. The performance of LCS was examined in a variety of environmental settings throughout the research period. The factors such as reference bias, temporal drift, particle composition effect, Pearson correlation, sensor repeatability, and climatic influence on sensor data have been analyzed to assess their significance in the analytical results. Pearson correlations (r = 0.64 - 0.83) between the investigated devices demonstrated the efficacy of low-cost Plantower PM sensors in monitoring PM10 and PM 2.5 in the field. The correlation between the low-cost sensor and OPC was lower in sites with a more significant concentration of coarse particles. As expected, the measurements are also influenced by atmospheric conditions, particularly temperature and relative humidity. The time-series results also clearly show the increased concentration levels during the winter (greater than the national standards) but less in summer and winter. This study also attempts to analyze the air quality at different locations in Goa with LCS, and the PM concentration is compared with gravimetric samplers at those locations.