Assessing air pollution in a coastal urban setting: contributions of PM₁₀, vehicular emissions, and public health impacts

Abstract

This study investigates the concentration and variation of key air pollutants SO₂, NOx, PM₁₀, and PM₂.₅ from 2009 to 2022 in Thiruvananthapuram, a city relatively free from industrial activities. SO₂ levels consistently remained well below the National Ambient Air Quality Standards whereas, PM₁₀ levels rose significantly, and often exceeded permissible limits. ICP-MS analysis revealed that Na, Zn, and Ca constitute up to 60% of the PM₁₀ mass, with major sources including sea salt, vehicular emissions, and construction activities. SEM and EDS analyses indicated a significant presence of carbonaceous particles and trace elements like Ba and Zn, which are linked to vehicular emissions and pose severe health risks. The presence of black carbon (BC) and organic carbon further underscores the contribution of transportation to air pollution. These findings are found to be consistent with broader national and global air quality challenges. The rising PM₁₀ levels mirror trends observed in other Indian cities, where urbanization and vehicular emissions remain the primary pollution sources. On a global scale, the presence of hazardous pollutants such as BC and heavy metals in urban environments is a critical public health concern. This study underscores the urgent need for targeted local air quality management strategies that align with national and global efforts to mitigate air pollution and protect public health.