Resumen: Aims
This study estimates long-term effects of air pollution and greenness on the incidence of pre-/hypertension in children and adolescents.
Methods and results
Exposures to particulate matter <2.5 µm (PM2.5), black carbon (BC), and nitrogen dioxide (NO2) at the residential addresses of 2385 children and adolescents of the IDEFICS/I.Family cohort were estimated using land use regression models; environmental greenness was assessed using the Normalized Difference Vegetation Index (NDVI). Applying g-computation, we estimated the effects of hypothetical reductions of PM2.5, BC, NO2, and increases of NDVI on the incidence of pre-/hypertension over a 6-year period compared with no intervention. The observed risk of developing pre-/hypertension was 14.4%. We found a dose-dependent relationship showing higher risk reductions when imposing lower hypothetical levels or larger percental reductions for the air pollutants. The largest effects were observed for PM2.5, e.g. reducing PM2.5 to ≤10 μg/m3 lowered the risk of developing pre-/hypertension by −10.7 [−14.1, −5.7; 95% bootstrap CI] percentage points compared with no intervention. Effects of BC reductions were less strong, e.g. −5.3 [−10.2, 1.7] when reducing BC to ≤0.8 × 10−5/m and small (non-significant) effects were found for NO2. Hypothetically increasing NDVI to ≥0.6 lowered the pre-/hypertension risk by −1.5 [−2.9, −0.4]. Sensitivity analyses suggested effects of air pollution mainly on systolic (SBP) but not diastolic blood pressure.