Modeling spatial PM_2.5 risk dynamics and projecting disease burden in Pakistan

Area of Science:

• Environmental Health
• Public Health
• Epidemiology

Background:

• Air pollution, particularly PM2.5, poses a significant public health challenge in Pakistan.
• Long-term health impacts and spatiotemporal variations in PM2.5 exposure and mortality are understudied.
• A high-resolution analysis is needed to understand exposure trends and associated mortality over time.

Purpose of the Study:

• To investigate spatiotemporal variations in PM2.5 exposure and its associated mortality burden in Pakistan from 2000 to 2021.
• To project future spatiotemporal changes in mortality under business-as-usual and mitigation scenarios.
• To identify high-risk zones and demographic vulnerabilities related to PM2.5 exposure.

Main Methods:

• Applied the Global Exposure Mortality Model (GEMM) using 0.01° resolution gridded PM2.5 and population data.
• Quantified PM2.5-attributed mortality for ischemic heart disease (IHD), cerebrovascular disease (CEV), COPD, LRI, and lung cancer (LC).
• Analyzed spatiotemporal trends and projected future mortality based on different exposure scenarios.

Main Results:

• PM2.5 levels and associated mortality have escalated and expanded geographically across Pakistan.
• High-risk zones with PM2.5 concentrations exceeding 80 μg/m³ were identified in densely populated areas.
• PM2.5-related deaths increased from 57,100 in 2000 to 157,762 in 2021, with IHD being most sensitive.
• Hotspots for IHD and LRI mortality were found near the Indus River basin.
• Central regions showed an annual PM2.5 increase of over 2 μg/m³.

Conclusions:

• Uncontrolled PM2.5 rise could lead to over 290,000 deaths annually by 2030, with IHD significantly increasing.
• Mitigation scenarios show potential to drastically reduce mortality to 29,062 by 2030.
• Urgent implementation of mitigation policies is crucial to address demographic vulnerabilities and reduce the existential risk posed by air pollution.