GHEAS Research Team
This working paper presents the first analytical module of the Global Health Evaluation and Assessment System (GHEAS). Using a harmonized country-year dataset, we examine the relationship between ambient PM2.5 exposure and life expectancy across a broad international sample. The descriptive evidence shows a negative association in the latest cross-section, but the association becomes substantially weaker once income, urbanization, demographic structure and health-system context are taken into account. The findings are best interpreted as descriptive and model-based evidence rather than a causal claim.
Air pollution and population health have long been studied together, yet the evidence base often remains fragmented across datasets, methods and disciplinary traditions. GHEAS is designed to bring these elements into a single, transparent workflow so that a research question can be examined from data provenance through interpretation.
The study uses a harmonized country-year structure with 200 countries and 6,800 matched observations in the core sample. The outcome is life expectancy at birth, and the exposure is annual mean PM2.5 concentration. Additional covariates include GDP per capita, urbanization, age 65+ share, health spending and regional indicators.
The raw cross-sectional pattern is negative. In the latest comparison, the correlation is approximately -0.582, indicating a clear descriptive association. However, once development conditions are introduced, the estimated PM2.5 coefficient shrinks markedly.
The findings support a cautious interpretation. The data are consistent with the view that PM2.5 exposure and life expectancy are linked in descriptive terms, yet the relationship appears highly sensitive to context and confounding structure.
This first GHEAS module demonstrates a reproducible research workflow that begins with traceable data, moves through descriptive and adjusted analysis, and ends with a clear statement of uncertainty.