Air quality dynamics and health risks: particle morphology and chemistry during pre and post-holi festival in a Tourist City in India

Abstract

The study examines the impact of Holi 2023 and the Holika Dahan ritual on air quality in Agra, India with a focus on health risks associated with increased particulate matter (PM) exposure and the chemical nature of the emitted particles. Air samples were collected before, during, and after the festivities, and the results showed a sharp increase in particulate matter (PM) concentrations, exceeding the World Health Organization's 24-h average guidelines and the National Ambient Air Quality Standard of India. Morphological and compositional analysis revealed distinctive particle types across different phases of the festival. Pre-Holi samples showed minimal particulate deposits, primarily carbon-rich particles mixed with mineral dust from vehicular emissions, construction, and resuspended soil. During Holika Dahan, a significant deposition of fine carbonaceous particles was observed, including soot aggregates and fullerenes like structure. These highly stable carbon structures contribute to atmospheric warming. Additionally, silica-based particles re-solidified from molten minerals at high temperature were identified, indicating intense combustion processes. Hybrid organic-mineral particles containing metals and sulphur were also present, suggesting interactions between soil dust and combustion emissions, posing inhalation risks and potential soil acidification upon deposition. Health risk assessments showed a significant increase in mortality risks linked to short-term PM exposure. Relative risk (RR) for PM_2.5 in terms of cardiopulmonary mortality increased by 86.35% during Holika Dahan while for lung cancer mortality, PM_2.5 exhibited an increase in RR by 153.83%, suggesting a substantial proportion of health risks could be directly linked to the elevated PM levels during the festival. These findings highlight urgent environmental concerns and the need for increased public awareness and regulatory measures to mitigate the adverse health impacts associated with traditional cultural and ritual practices that contribute significantly to air pollution.