## 1 Introduction  
Urbanization and industrialization are the main sources of air pollution in the world. Consequently, air pollution has become the main topic of many environmental studies [1, 2, 3, 4, 5]. The World Health Organization states that air pollution is a threat to human health and is responsible for millions of deaths annually [6, 7, 8, 9]. Annually, about 21,000 Canadians die due to exposure to polluted air [10]. Several studies have shown a positive correlation between cancer and exposure to polluted air in different parts of the world [11, 12] and in the Arabian Peninsula [13]. The industrial areas in the world are the main contributors to air pollution and are responsible for the deteriorating health of the population. In Riyadh, the capital of Saudi Arabia, industrialization has increased dramatically during the past couple of decades in response to the increase in population and urban development. Establishment of two industrial cities has resulted in better employment opportunities and, consequently, a high population growth of about 4% in Riyadh [14]. The First Industrial City was established in 1973 and has an area of 0.5 km\({}^{2}\). The Second Industrial City was established in 1976 and has an area of 19 km\({}^{2}\)[15]. Though the Second Industrial City and the Saudi Aramco Oil Refinery (Al-Misfat) were established in the south of Riyadh, far from the city, urban expansion and associated economical activities forced the people to live around the industrial cities. Accordingly,overcrowded buildings, especially along roads; an increase in traffic and vehicular emissions; and frequent desert dust storms in the area were the principal sources that increased the level of environmental pollutants [16], leading to air pollution [17]. The cumulative effect of these factors resulted in deterioration of air quality indoors and outdoors at many sites in Riyadh [18]. During several visits to the study area in southern Riyadh, it was evident that the area is suffering from multiple aspects of pollution, reduction in visibility during the mornings, and dirty and eroded buildings. Accordingly, residents and workers complained of unhealthy air quality in the area. Several efforts have been made to study the concentration of chemicals and particulate matter in the air in Saudi Arabi [19; 20; 21]; however, most studies were limited and not comprehensive due to insufficient data [18]. As a result, the Royal Commission for Riyadh City and the General Authority of Meteorology and Environment Protection are operating 32 air quality control stations in Riyadh, over the past few years, to monitor the air quality. Some of these monitoring stations are fixed, whereas others are mobile. In addition, the General Authority of Meteorology and Environment Protection launched a dashboard for Riyadh air quality [22] to visualize the air quality index (AQI). Mapping techniques are useful to assist decision makers in quantifying and locating pollution sites, even with limited measurements. (Geographic information system) GIS and remote sensing are useful tools for spatial analysis and detection of thermal pollution. Geostatistics is a strong technique to assess the spatial analysis of the studied variables [23]. The kriging technique is widely used for investigating sources of pollution as it is a reliable technique with fewer errors, even with small samples [24; 25; 26]. In addition, remote sensing imageries, especially in the thermal bands, provide simpler and more accurate information about surface temperature and emissivity [27] to detect urban heat islands (UHIs) [28; 29; 30]. Accordingly, this study aims to shed light on the opinions of residents living in southern Riyadh, near the industrial city, regarding emissions of oxides and particulate matter from industrial areas and traffic congestion. Most studies when surveying about the quality of life in cities do not take into account people's opinions about air pollution aspects.