Meteorological effects on particulate matter PM₁₀, PM_2.5 concentrations with diurnal and seasonal variations in cities neighboring desert lands

The presence of desert lands in some countries along with meteorological factors makes particulate matter their main pollutant. Particulate matter PM_2.5 and PM₁₀ have attained more concern due to their adverse effects on human health. This study aimed to investigate the temporal characteristics of PM_2.5, PM₁₀, PM_2.5–10 and PM_2.5/PM₁₀ and their relationship with meteorological factors. In addition, the exceedances will be described according to WHO guidelines. Two cities neighboring desert areas with large population, Baghdad and Mosul/Iraq were selected to conduct the study. The study is based on hourly data from the official monitoring networks for a year from Jan to Dec 2022. The results showed significant variation in PM according to month and season in Mosul and Baghdad. The highest PM_2.5 occurred in autumn versus summer for PM₁₀ and PM_2.5–10 in Mosul city. While, the highest PM_2.5 in Baghdad city was found in winter and spring versus summer for PM₁₀ and PM_2.5–10. The annual average of PM_2.5 was more than twofold WHO interim Target-IV annual guideline in Mosul city versus more than threefold in Baghdad city. The number of polluted days in Mosul city was 226 versus 358 in Baghdad according to PM₁₀ WHO Target-IV. Wind speed has the highest and direct ability to predict PM, while short wave radiation has the highest inverse prediction ability according to regression analysis. The highest and lowest PM_2.5 concentrations occurred with winds coming from same direction, but at highest concentration the wind was faster in Mosul and Baghdad. The diurnal variation of PM_2.5 has unimodal in Mosul and Baghdad, while PM₁₀ showed a bimodal pattern. These results highlight the need to reduce the impact of desert areas on air quality and it can be very beneficial for the management and control of PM.