Association between long-term exposure to air pollution and blood pressure in children: an updated systematic review...

Ambient air pollution is a modifiable environmental exposure that may contribute to early cardiovascular risk. Although long-term exposure has been linked to blood pressure (BP) dysregulation, research on its effects in children remains limited, despite their particular vulnerability during critical periods of cardiovascular development. This updated systematic review and meta-analysis aimed to estimate pollutant-specific associations of long-term air pollution exposure with BP and hypertension in children and adolescents.

Following PRISMA guidelines, studies were identified from prior systematic reviews and meta-analyses as well as an updated PubMed and Web of Science searches through March 27, 2025. Twenty-one studies, including 990,157 participants, were included in the systematic review evaluating air pollutants, including PM₁, PM_2.5, PM₁₀, NO, NO₂, NO_x, SO₂, O₃, and CO. Meta-analysis was limited to PM_2.5, PM₁₀, and NO₂ because cohort data for other pollutants were limited, and exposure increments and hypertension definitions varied across studies.

Long-term PM_2.5 exposure showed the most consistent association with higher systolic BP (0.59 mmHg per 10 μg/m³; 95 % CI: 0.28-0.90). PM₁₀ was initially associated with higher systolic (0.28 mmHg per 10 μg/m³; 95 % CI: 0.25-0.31) and diastolic (0.27 mmHg; 95 % CI: 0.24-0.30) BP, but these associations were not sustained in sensitivity analyses. NO₂ showed no significant association with systolic or diastolic BP. Several pollutants, including PM_2.5, PM₁₀, SO₂, O₃, and CO, were associated with increased odds of hypertension.

Current evidence suggests that exposure to fine particulate matter may contribute to early-life elevation in blood pressure; however, given the paucity of longitudinal data and the complexity of multipollutant exposures, further research employing standardized exposure metrics, harmonized outcome definitions, and multipollutant models are needed to clarify independent pollutant effects.