Two Decades of Air Pollution Health Risk Assessment: Insights From the Use of WHO’s AirQ and AirQ+ Tools

Objectives: Authors evaluated studies that used the World Health Organization’s (WHO) AirQ and AirQ+ tools for air pollution (AP) health risk assessment (HRA) and provided best practice suggestions for future assessments.

Methods: Authors performed a comprehensive review of studies using WHO’s AirQ and AirQ+ tools, searching several databases for relevant articles, reports, and theses from inception to Dec 31, 2022.

Results: Authors identified 286 studies that met their criteria. The studies were conducted in 69 countries, with most (57%) in Iran, followed by Italy and India (∼8% each). Authors found that many studies inadequately report air pollution exposure data, its quality, and validity. The decisions concerning the analysed population size, health outcomes of interest, baseline incidence, concentration-response functions, relative risk values, and counterfactual values are often not justified, sufficiently. Many studies lack an uncertainty assessment.

Conclusion: This review found a number of common shortcomings in the published assessments. Authors suggest better practices and urge future studies to focus on the quality of input data, its reporting, and associated uncertainties.