Spatio-temporal variability of particulate matter and associated mortality risk over major urban areas across the Indo-Gangetic Plain

Abstract

Environmental pollution due to fine particulate matter (particulate matter ≤ 2.5 μm; PM_2.5) is a major health concern worldwide, especially in India. In the post-monsoon and winter seasons, meteorological conditions favor the confinement of aerosols, leading to higher concentrations of PM_2.5 in the Indo-Gangetic Plain (IGP). Scientific research has associated PM_2.5 exposure with various causes of premature mortality, including ischemic heart disease (IHD), chronic obstructive pulmonary disease (COPD), and lung cancer (LC). This study investigates spatial and temporal variability and transport of particulate matter (utilizing the airmass back trajectory analysis) over six states in the IGP to gain insights into their origin and transport, during the most polluted (post-monsoon and winter) seasons. Among all monitored locations, Delhi reported the greatest PM_2.5 loading during the winter and post-monsoon seasons (170.47 ± 84.80 µg m⁻³), followed by Patna, Bihar (130.47 ± 61.97 µg m⁻³). Using the Integrated Exposure–Response (IER) model, our analysis indicates that annual exposure to PM_2.5 could lead to more than 3,000 premature deaths per million people in each city, based on the WHO guideline limits. This study presents a comparative assessment of PM concentrations and the associated mortality risks across six states of the Indo-Gangetic Plain (IGP), with two monitoring sites in each state. The findings provide valuable insights to support policymakers in developing effective air quality management and mitigation strategies.

Graphical abstract