Journal of Environmental Sciences · Jan 21, 2025
Cumulative effect of PM2.5 chemical components surpasses PM2.5 mass on hypertension in older adults: A China-based national analysis
By Chen C, Su B, Wang Y et al.
The specific and cumulative effects of fine particulate matter (PM2.5) components on hypertension remain less defined, notably in susceptible older adults. This national study utilized a representative sample of 220,425 older adults in China, to scrutinize their relationship. Residential PM2.5 and five chemical components (black carbon (BC), organic matter (OM), sulphate (SO₄²⁻), nitrate (NO₃⁻), and ammonium (NH₄⁺)) were estimated by the bilinear interpolation. Associations between PM2.5 and five chemical components with hypertension were examined through two-stage logistic regression models, with population attributable fractions (PAFs) determined via counterfactual analysis. Elevated exposure to PM2.5 and its components was generally linked to higher hypertension prevalence. With each interquartile range increase, the odds ratio (OR) of hypertension rose by 1.09 (95 % CI: 1.08-1.11) for NO₃⁻, 1.06 (95 % CI: 1.05-1.08) for NH₄⁺, 1.06 (95 % CI: 1.05-1.07) for OM, 1.05 (95 % CI: 1.04-1.06) for BC, and 1.06 (95 % CI: 1.04-1.07) for SO₄²⁻. Notably, the cumulative impact of five PM2.5 chemical components (OR: 1.13, 95 % CI: 1.12-1.13) was significantly greater than the effect of total PM2.5 mass alone (OR: 1.04, 95 % CI: 1.03-1.05). Regarding PAFs, NO₃⁻ represented the strongest contribution to hypertension, followed by OM, NH₄⁺, SO₄²⁻, and BC. Furthermore, the effects were accentuated in low socio-economic population. These findings underline that using total PM2.5 as a surrogate marker may underestimate the comprehensive impact of its chemical components, underscoring the necessity for targeted interventions to reduce emissions of specific PM2.5 chemical constituents.