## 4 Discussion  
Usually, the sources of gaseous pollutants are measured in three categories: natural emission mechanism, combustion sources and industrial manufacturing processes. Industrial sources of particulates, like steel, heavy traffic loads, indiscriminate burning of solid wastes and cement factories are the main sources of PM [2, 28] besides gaseous and noise pollutants. The increasing air pollution is, after losses of properties, crops and increased health care costs. Airborne particulate matter is abundant in the atmosphere and varies extensively (temporally and spatially) in size, chemical composition and concentration. Emissions of particulate matter towards air are the focal environmental challenges for the transport and industrial sectors [4]. According to the WHO report, South Asia has developed as one of the most polluted zones in the globe because of its increasing population and rapid industrialization. Acquaintance to PM leads to more appointments to the emergency room or doctor. Health effects include premature deaths with existing lung and heart diseases, lung damage, coughing, aggravated asthma, wheezing and shortness of breath. Specifically, in the dry and cold season in major urban areas of Pakistan, people of almost all ages suffer from throat infections as reported [2, 4, 17]. In Pakistan, like the other developing countries, the emissions from vehicles have been conquered by emissions from poorly maintained and old vehicles that subsidize to heightened mass concentrations of carbon monoxide and fine particulates [17, 28]. The current study focused on particulate volume has reported the highest concentration of PM\({}_{2.5}\) and PM\({}_{10}\) in a commercial area on the average 39.18 \(\pm\) 4.70 ug/m\({}^{3}\), 573.14 \(\pm\) 321.64 ug/m\({}^{3}\) and 40.73 \(\pm\) 2.9 ug/m\({}^{3}\), 575.19 \(\pm\) 225.66 ug/m\({}^{3}\) for summer and winter, respectively (Figure 2). While, the lowest concentration of PM\({}_{2.5}\) and PM\({}_{10}\) was obtained in the residential sector ranging (33.91 \(\pm\) 3.27 ug/m\({}^{3}\)), (35.1 \(\pm\) 2.93 ug/m\({}^{3}\)) and (349.46.75 \(\pm\) 74.49 ug/m\({}^{3}\)), (350.98 \(\pm\) 74.29 ug/m\({}^{3}\)) for summer and winter season correspondingly with a strong positive correlation between PM\({}_{2.5}\) and PM\({}_{10}\) in both seasons on average. According to the guidelines, the reference value for PM\({}_{2.5}\) and PM\({}_{10}\) are WHO (25 ug/m\({}^{3}\) and 50 ug/m\({}^{3}\)) [17, 25], NEQS and US-EPA (35 ug/m\({}^{3}\), 150 ug/m\({}^{3}\)) [26, 27] and most samples examined in the present study had values higher than the reference values. Elemental carbon is discharged from a variety of ignition procedures, categorized as a short-lived climate force that put up to atmospheric warming and also allied with human mortality and morbidity [28]. Common sources of atmospheric primary and secondary organic carbon antecedents are biomass burning, vehicular exhaust, biogenic emission and industrial emissions [29]. During the winter season, a higher level of pollutants especially the mass concentration of PM\({}_{2.5}\) persists in the ambient air of Faisalabad, owing to reduced atmospheric dispersion due to high relative humidity. Similarly, it was observed that PM\({}_{2.5}\) and PM\({}_{10}\) sources were frequently localized as depicted by high concentrations at low wind speeds, mostly by the emissions from road vehicles [2, 29]. This demonstrates the fact that PM\({}_{2.5}\) and PM\({}_{10}\) concentrations were lower in summer than in winter (Figure 2) due to an increase in wind speed and temperature. Prior studies conducted in the carbonaceous aerosols were assessed to account for about 50-60% of the total mass of PM\({}_{2.5}\) in metropolises in Jordan, Israel and Palestine [30]. Not unexpectedly, since production and processing of oil was prevalent transversely in the Middle East, substantial oil burning was valued to contribute 18% to total mass of PM\({}_{10}\) and 69% to the total mass of PM\({}_{2.5}\) in Jeddah, Saudi Arabia [31].