Role of Outdoor Air Pollution, Noise Pollution, and Green Exposure on Abdominal Aortic Aneurysm Progression

Recent evidence suggests an association between air pollution exposure and abdominal aortic aneurysm (AAA) rupture. It is unclear whether environmental factors also influence the rate at which AAAs grow. This study aimed to determine how environmental factors contribute to aneurysm growth using a prospective cohort study design.

This study used data from the UK Aneurysm Growth Study (UKAGS), a national cohort of men with AAA representative of the UK population in AAA surveillance. Participant records were linked with environmental exposure data from a validated land use regression model, including nitrogen dioxide (NO₂) concentrations (μg/m³), particles with an aerodynamic diameter < 2.5 μm (PM_2.5) concentrations (μg/m³), satellite measures of greenness (normalised difference vegetation index, enhanced vegetation index, and tree cover density), Ordnance Survey derived greenspace, and noise pollution exposure (dB) from three sources (aircraft, railway, and road), over a ten year period (2010 - 2019) with a 25 × 25 m grid cell resolution. Linear mixed effect growth modelling was used to explore the association with AAA growth.

Environmental data were available for 3 360 (86.0%) participants. Mean follow up ± standard deviation was 5.64 ± 2.47 years. There were no statistically significant associations between NO₂, PM_2.5, and transport noise pollution with AAA growth in adjusted models, whereas relationships with greenspace measures were inconsistent.

The link between environmental factors and AAA growth remains unclear. Potential issues include use of those participating in a screening programme (who may be healthier than the general population and less susceptible to environmental influences). Managing traditional risk factors, especially smoking, remains key to clinical care.