Impact of Air Pollution and Greenness on Pediatric Pre-/Hypertension Risk
Overview
This study evaluated the long-term effects of air pollution and environmental greenness on the incidence of pre-/hypertension in 2385 European children and adolescents. Reductions in PM2.5 and black carbon were associated with significant decreases in pre-/hypertension risk, primarily through lowering systolic blood pressure, while increases in greenness and reductions in NO2 showed smaller effects.
Background
Hypertension is a critical risk factor for cardiovascular disease that can begin in childhood. Environmental exposures such as particulate matter (PM2.5), black carbon (BC), and nitrogen dioxide (NO2) have been linked to elevated blood pressure in pediatric populations. Conversely, greater residential greenness may offer protective effects. Due to ethical and practical constraints on randomized trials, causal inference methods like g-computation applied to observational data provide valuable insights into the potential impact of environmental interventions on blood pressure outcomes.
Data Highlights
Exposure
Hypothetical Intervention
Risk Reduction in Pre-/Hypertension (%) [95% CI]
PM2.5
Reduced to ≤10 μg/m³
−10.7 [−14.1, −5.7]
Black Carbon (BC)
Reduced to ≤0.8 × 10⁻⁵/m
−5.3 [−10.2, 1.7]
Nitrogen Dioxide (NO2)
Reduced levels
Small, non-significant effect
Normalized Difference Vegetation Index (NDVI)
Increased to ≥0.6
−1.5 [−2.9, −0.4]
Key Findings
The baseline risk of developing pre-/hypertension over 6 years was 14.4% in the cohort.
Reducing PM2.5 to recommended levels (≤10 μg/m³) significantly lowered pre-/hypertension risk by approximately 10.7 percentage points.
Lowering black carbon exposure also reduced risk, though effects were smaller and less consistent.
Reductions in NO2 showed only minor and statistically non-significant protective effects.
Increasing residential greenness (NDVI ≥0.6) modestly decreased risk by about 1.5 percentage points.
Protective effects were mainly due to reductions in systolic blood pressure rather than diastolic pressure.
Clinical Implications
Clinicians should recognize the potential cardiovascular benefits of environmental interventions in pediatric populations. Efforts to reduce particulate air pollution, especially PM2.5 and black carbon, may substantially decrease the incidence of elevated blood pressure in children and adolescents. Additionally, promoting urban greenness could offer modest protective effects. These findings support public health policies targeting air quality improvements to reduce future cardiovascular disease burden.
Conclusion
This study provides evidence that lowering ambient air pollution, particularly PM2.5, and enhancing residential greenness can reduce the risk of developing pre-/hypertension in children and adolescents. Targeted environmental interventions may be an effective strategy to prevent early cardiovascular risk.
References
Ahrens et al. 2024 -- Impact of Environmental Air Contaminants and Green Spaces on the Development of Pre-/Hypertension in Pediatric Populations
by Maike Wolters, Rajini Nagrani, Nour Naaouf, Stefaan De Henauw, Lauren Lissner, Luis A Moreno, Dénes Molnár, Paola Russo, Tanja Vrijkotte, Wolfgang Ahrens, Claudia Börnhorst, on behalf of the IDEFICS/I.Family consortium
