Ambient PM2.5 exposure is linked to elevated platelet count and reduced serum creatinine: a cross-sectional study in the UK Biobank

Air pollution, particularly fine particulate matter (PM2.5) is a major risk factor for cardiovascular and renal disease. Using UK Biobank data, we examined associations between World Health Organization PM2.5 classes and 18 blood biomarkers. We conducted (i) descriptive class-mean summaries and (ii) individual-level Pearson trend tests with Benjamini–Hochberg false discovery rate (BH-FDR) control across biomarkers. PM2.5 class showed a positive association with platelet count and a negative association with serum creatinine; both signals were consistent across descriptive trajectories and remained significant after BHFDR adjustment. While several additional biomarkers reached statistical significance, effect sizes were uniformly small. Findings support the hypothesis that ambient air pollution is linked with systemic physiological changes relevant to cardiovascular (pro-thrombotic) and renal health and underscore the potential value of biomarker monitoring in population health assessments.