Integrated remote sensing and socio-economic evaluation of winter smog and its impacts in Lahore district, Pakistan

Winter smog has become critical for the environment and public health in major cities of South Asia, especially Lahore district, Pakistan. The present study is based on an integrated assessment of winter smog using the remote sensing (RS) observations combined with socio-economic survey data, which is used to analyse the spatial distribution of smog and the impacts associated with it. MODIS MAIAC (MCD19A2) and Sentinel-5P TROPOMI (tropospheric nitrogen dioxide - NO₂) Aerosol Optical Depth (AOD) products were used to study the temporal and spatial variation of the atmospheric pollution over winter seasons (2019–2021). At the same time, a structured questionnaire survey was carried out with vulnerable occupational groups such as labourers, street vendors, and traffic police and service workers in order to find out about their perception of health, environment and socio-economic effects. The AOD values exhibited temporal variations during the study period, ranging from 1.062 to 0.809, indicating changes in atmospheric aerosol loading associated with seasonal and anthropogenic emission sources. A temporary reduction in aerosol and NO 2 concentrations was observed during 2020, likely associated with COVID-19 mobility restrictions. Risk zone assessment identified Lahore and surrounding districts, including Sheikhupura, Kasur and Gujranwala, as highly vulnerable areas. The survey results indicated that the problem of health effects due to smog is very common, such as discomfort of the respiratory tract, decreased outdoor activity, and economic problems. This study underlines the importance of using remote sensing and socio-economic methods to assess air quality comprehensively. The results serve to enhance knowledge of the dynamics of winter smog and to support policy interventions aimed at reducing air pollution in urban areas based on evidence.