Introduction: Air pollution, particularly smog, is an escalating environmental and public health crisis in urban areas. Smog arises from a combination of anthropogenic activities and natural processes, with human-generated pollutants being the primary contributors. The most significant causes of smog include vehicular emissions, industrial activities, burning of fossil fuels, and agricultural practices. Additionally, environmental conditions such as temperature inversions and high humidity further exacerbate smog formation. The impact of smog on public health and the environment is severe, making its prevention and control an urgent priority for both policymakers and public health officials. In smog prone regions like Lahore, Pakistan, the concentration of pollutants such as heavy metals and particulate matter is particularly high due to industrial emissions, vehicular exhaust, and the burning of fossil fuels. This study evaluates the correlation between smog exposure and blood heavy metals levels (copper, cadmium & zinc) among residents of Lahore and Murree, two regions in Pakistan with significantly differing air quality. Methodology: A cross-sectional analysis was conducted with 90 participants specifically targeted the population of working people in open air like fruits and vegetable seller that mostly time they faced smog pollution (45 from Lahore and 45 from Murree) and these samples are categorized into four age groups (18–30, 31–40, 41–50, and 51–65 years). Blood heavy metals levels like cadmium, copper and zinc were measured using Atomic Absorption Spectroscopy (AAS), and air quality data for both regions were obtained for the months of September to November 2024 from the source of Pak-EPA. Finding: The results revealed significant differences in metal concentrations between the two regions, with Lahore exhibiting markedly higher levels of copper, cadmium, and zinc across all age groups (p < 0.05). Mean serum copper levels in Lahore ranged from 120 µg/dL in the 18–30 age group to 180 µg/dL in the 51–65 age group, compared to 80 µg/dL to 110 µg/dL in Murree. Similarly, cadmium and zinc levels were consistently higher in Lahore, correlating with the Air Quality Index (AQI), which ranged from "Unhealthy" to "Hazardous" in Lahore and "Moderate" in Murree. Older age groups in both regions exhibited higher metal levels, indicating cumulative exposure over time. Conclusion: This study highlights that smog, driven by industrial and vehicular emissions, is a significant source of heavy metal exposure in urban environments. Elevated levels of copper, cadmium, and zinc in the blood are strongly associated with poor air quality, posing substantial health risks. These findings underscore the urgent need for stringent environmental regulations, effective public health interventions, and widespread awareness campaigns to mitigate the adverse health impacts of smog exposure, particularly in densely populated urban areas like Lahore.