## 4 Discussion
Likewise, in Faisalabad, Pakistan, the quality of air not only reflects the impact of regional and local dust but also momentous local sources which include numerous industries and a heavy traffic weight. In municipal areas, the higher concentrations of PM\({}_{2.5}\) and PM\({}_{10}\) are symbolic of the higher density of traffic as presented in the current study (Figures 2 and 4). Additionally, the burden of particulates is higher in the daytime than nighttime one, demonstrating more urban activities throughout day time. In Faisalabad, the textile industry, the topographical configuration and the geographical location make the problem of air pollution so perilous that it is very crucial to study it (Figure 5). The current study aimed at finding out whether or not the situation of air pollution in Faisalabad was previously seriously abundant to warrant the establishment of a regular air quality management system through which intercession measures can be premeditated and executed. The analysis result of ambient air samples of selected sites of Faisalabad city displays that the level of particulate matter in most of the areas of the city is above the indorsed levels of the WHO, NEQS and US-EPA. Most of the city's commercial and residential areas are within the sensitive zone with the maximum concentrations of PM, which is constant with their proximity to the city's industrial areas. When compared with the other studies conducted in other cities, it was found that the PM\({}_{2.5}\) level at Industrial Estate I-10 and IJP Road has reached the critical level (\(>\)35 ug/m\({}^{3}\)) whereas at Industrial Estate I-9 it was moderate to the high level (31.9 ug/m\({}^{3}\) to 41.1 ug/m\({}^{3}\)) [27]. While, the mean concentration of PM\({}_{2.5}\) and PM\({}_{10}\) for Peshawar city during the study period has been calculated to be respectively 172 ug/m\({}^{3}\) and 480 ug/m\({}^{3}\)[32]. A similar high mass concentration of particulate matter was observed by [33] at Lahore, Pakistan and documented that the average PM\({}_{2.5}\) mass was 190 ug/m\({}^{3}\), and ranged from 89 ug/m\({}^{3}\) to 476 ug/m\({}^{3}\), far over US-EPA standards. Much higher PM\({}_{10}\) mass concentration was experienced in Faisalabad when compared with other megacities [34]. In addition, the PM\({}_{10}\) concentrations were quite higher than the annual mean PM\({}_{10}\) concentrations in Eastern Mediterranean and Africa [35; 36] (WHO. Ambient (outdoor) 2014), Malaysia [34] and Bogota, Egypt, Los Angeles and Mexico [34]. It was also identified that PM\({}_{10}\) is the dominant pollutant in the index value [37]. While, according to the results obtained after the analysis of particulate matters samples, the highest concentration of elemental carbon was 103.12 \(\pm\) 1.46 ug/m\({}^{3}\) and the highest concentration of organic carbon was 196.9 \(\pm\) 1.79 ug/m\({}^{3}\). While, 300.02 \(\pm\) 3.25 ug/m\({}^{3}\) was the highest TC concentration found in the samples of coarse particulate matter collected in the vicinity of Nazria Pakistan (Figure 3). When compared, it was found that these concentrations are comparatively higher than in other metropolises in the areas like Punjab, India (116 ug/m\({}^{3}\)), Hangzhou, China (119 ug/m\({}^{3}\)), Kolkatta, India (197 ug/m\({}^{3}\)), New Delhi, India (219 ug/m\({}^{3}\)) and Lahore, Pakistan (233 ug/m\({}^{3}\)) [38; 39; 40]. For elemental carbon, a large number of sources are identified, e.g., biomass and coal-fired power plant, two-stroke vehicles, fossil fuel burning, diesel engines and low burning efficiency. Elemental carbon is also utilized as a tracer for vehicular emission [17; 40]. It was stated by [41] that diesel and gasoline motor vehicles and traffic exhaust are key sources of elemental carbon, followed by biomass burning. Organic carbon can be released straight from sources identified as primary carbon as a result of biomass and fossil combustion or can be formed as a result of a chemical reaction recognized as secondary organic carbon [42].