Long-term exposure to PM2.5 and NO2 is independently associated with more advanced coronary atherosclerosis at cardiac CT, even at moderate contemporary exposure levels, with obstructive CAD associations observed specifically in women but not men.
Key Findings
Results
Greater PM2.5 and NO2 exposures were independently associated with higher coronary artery calcium scores in multivariable analysis.
PM2.5 association with CACS: incidence rate ratio (IRR) = 1.11, P < .001
NO2 association with CACS: IRR = 1.01, P = .04
Study included 11,128 patients who underwent cardiac CT (mean age 59.1 years ± 11.3; 51.7% men)
Median 10-year PM2.5 exposure was 7.5 µg/m³ (range 4.3–9.2 µg/m³); median NO2 exposure was 13.4 ppb (range 3.2–17.8 ppb)
Negative binomial regression models were adjusted for clinically relevant covariates
Results
Greater PM2.5 and NO2 exposures were independently associated with greater total coronary plaque burden in multivariable analysis.
PM2.5 association with total plaque burden: OR = 1.13, P = .02
NO2 association with total plaque burden: OR = 1.04, P < .001
Ordinal logistic regression models were used for plaque burden analysis
7,313 patients underwent coronary CT angiography (mean age 59.5 years ± 11.5; 48.7% men)
Results
Long-term air pollution exposure was associated with obstructive coronary artery disease (≥70% diameter stenosis) in women but not in men.
In women, PM2.5 was associated with obstructive CAD: OR = 1.81, P = .048
In women, NO2 was associated with obstructive CAD: OR = 1.06, P = .04
In men, PM2.5 showed no significant association with obstructive CAD: OR = 1.14, P = .38
In men, NO2 showed no significant association with obstructive CAD: OR = 1.03, P = .13
These findings came from maximally adjusted models stratified by sex
Methods
The study evaluated long-term air pollution exposure over a 10-year period prior to cardiac CT using a multisite retrospective design.
Adult patients underwent outpatient cardiac CT for CAD evaluation between January 2012 and December 2023
Mean exposure to PM2.5 and NO2 was assessed over the 10-year period before cardiac CT
CT markers evaluated included CACS, total plaque burden, and presence of obstructive CAD (≥70% diameter stenosis)
Regression models were constructed and adjusted for clinically relevant covariates
The study was described as a multisite retrospective study
Results
The associations between air pollution and coronary atherosclerosis were observed at moderate contemporary exposure levels.
Median 10-year PM2.5 exposure was 7.5 µg/m³, with a range of 4.3–9.2 µg/m³
Median 10-year NO2 exposure was 13.4 ppb, with a range of 3.2–17.8 ppb
The authors characterized these as 'moderate contemporary exposure levels'
Air pollution is described as 'the leading environmental risk factor for cardiovascular disease'
What This Means
This research suggests that breathing polluted air over many years is linked to more severe buildup of plaque in the heart's arteries, even at pollution levels considered moderate by current standards. The study looked at over 11,000 patients who had specialized heart CT scans in Canada between 2012 and 2023, and estimated each person's average exposure to two common air pollutants — fine particulate matter (PM2.5, tiny particles from traffic and industry) and nitrogen dioxide (NO2, mainly from vehicle exhaust) — over the 10 years before their scan. Higher long-term exposure to both pollutants was associated with higher calcium scores in the arteries and greater overall plaque accumulation, even after accounting for other risk factors like age and smoking.
One of the most notable findings was a difference between men and women. When looking specifically at the most severe form of blockage (arteries narrowed by 70% or more), the association with air pollution was found only in women, not in men. Women with higher PM2.5 exposure had 81% higher odds of having severe coronary blockage, and higher NO2 exposure was also significantly linked to severe blockage in women. No such association was detected in men. This suggests that women may be particularly vulnerable to the heart-damaging effects of long-term air pollution exposure.
This research matters because it extends previous findings beyond simple calcium scoring to include more detailed measures of coronary artery disease visible on CT scans, and it highlights a potential sex-specific vulnerability. The findings reinforce that air pollution — even at levels within current regulatory standards — may contribute meaningfully to the development of serious heart disease, and that this risk may not be equal across sexes.
Castillo F, Ladak A, DesRoche C, Delaney S, Nethery R, Thavendiranathan P, et al.. (2026). Sex-Specific Associations between Long-term Air Pollution Exposure and Coronary Atherosclerosis at Cardiac CT.. Radiology. https://doi.org/10.1148/radiol.252086