Delhi is a commercial city and the people’s living standard is also comparatively high. Due to that, different active security agencies hire security guards and deploy them in various areas to protect people and properties. These security guards generally perform their duties outside the premises or near the roadside, leading to their continuous exposure to different size fractions of particulate matter. The present study is an effort to analyze the security guards’ exposure to different size particulate matter (PM2.5, PM1, PM0.5, and PM0.25) and toxic metals in different urban environments. The study showed that the PM2.5 concentrations were higher at all the selected locations, while the construction site depicted the highest concentration of all-size particles among all the identified locations. The ratio of PM1/PM2.5 was observed to be higher and indicated more contribution of PM1 size particles, specifically in commercial, construction, and roadside areas. After analyzing heavy metal presence in PM2.5 and PM1, out of 11 heavy metals, six metals (Fe, Cu, Pb, Cr, Mg, Zn) were found below the detection limit. Mg was found at higher concentrations in commercial, construction, and industrial areas in PM2.5 and PM1, while Zn was also found at higher concentrations in PM2.5 and PM1 at the roadside and residential sites. At the industrial site, the Cr concentration was observed highest in PM1, representing a serious concern to security guards of that area.