Abstract: In most developing countries, the air quality index is a relevant issue since it directly impacts human health and mobility. Commercial devices have already been used to describe the relationship between the air quality index and associated risks. But these results are not readily accessible to the general public, especially in semi-urban areas where threats of air pollution lurk with rapid urbanisation. The main idea is to use open-source wireless technologies for real-time monitoring of outdoor pollutants where free access to data on air pollution is not available. The result of the study shows the mean concentration of nitrous oxide ranges from 1.50 μg/m3 to 3.83 μg/m3 with the maximum being 6 μg/m3 and the minimum being 0 μg/m3. The average daily concentration of P.M10 ranges from 20.58 μg/m3 to 38.43 μg/m3 with a maximum 46 μg/m3 and the minimum 13 μg/m3. The average concentration of particulate matter P.M2.5 ranges from 30.04 μg/m3 to 53.39 μg/m3 with the maximum concentration being 59 μg/m3 and the minimum concentration being 2 μg/m3 in the study period. Similarly, the daily mean concentration of ozone varied between 19.87 μg/m3 and 34.75 μg/m3 with a maximum 52 μg/m3 and the minimum 5 μg/m3. The mean AQI value ranges from 34.54 to 54.30 with a maximum value of 91 and a minimum being 24. PM2.5 and PM10 showed a positive correlation (r2 = 0.998) with each other, indicating they came from the same source. Both PM2.5 and PM10 were negatively and weakly correlated with temperature and humidity. In the study, it is shown that PM10 acts as a single variable that affects the air quality index as a result of the combined effects of multiple factors.
Keywords: Developing countries, Semi-urban area, Air quality monitoring app, Air quality index, Microclimate