Prevalence of hypertension and cross-sectional associations between household air pollution exposure and blood pressure among children in rural Rwanda

Household air pollution (HAP) contributes to the global cardiovascular disease burden. Early life exposures may impact future disease risk; however, evidence of HAP’s impact on blood pressure (BP) among children in low-resource settings is limited. We assessed baseline cross-sectional associations between personal exposure to fine particulate matter (PM 2.5 ) and black carbon (BC) and children’s (8–15 years) systolic and diastolic BP (SBP, DBP) from the Sustainable Household Energy Adoption in Rwanda study. We enrolled 626 households in rural Eastern Rwanda that used traditional biomass fuels for cooking. Children wore Ultrasonic Personal Aerosol Samplers for 48 h monitoring of personal exposure, followed by BP measurement using standard protocols. Multiple linear regression was used to characterize associations between PM 2.5 and BC exposure and BP in separate models; effect modification by age and sex was evaluated. Among 622 children (mean age = 11.8 years, standard deviation [SD] = 2.1; males = 303, females = 319), the average SBP and DBP were 105.8 mmHg (SD = 10.0) and 68.3 mmHg (SD = 7.6), respectively. BP percentiles were higher than those in a US reference population (e.g. 59.0% and 85.5% had SBP and DBP percentiles >50th, respectively; 24% were classified as having elevated BP and/or were hypertensive, defined as ⩾90th percentile). The median 48 h PM 2.5 and BC concentrations were 192.9 µ g m −3 (25th percentile [ Q 1] = 119.7, 75th percentile [ Q 3] = 336.0) and 9.85 µ g m −3 ( Q 1 = 6.56, Q 3 = 13.23), respectively. We did not observe evidence of associations between HAP and BP levels (e.g. PM 2.5 –SBP = 0.51 mmHg per interquartile range [IQR, 211.7 μ g m −3 ] increase, 95% confidence interval: −0.46, 1.49). We did not observe clear evidence of effect modification. Exposures well above international health-based guidelines may have limited our ability to observe associations if the true exposure–response is flat in that part of the global exposure continuum. Importantly, our BP data suggest an elevated cardiovascular disease burden among children in this low-resource setting compared to in the US, demonstrating a need for more research and the development of more appropriate reference data in these settings. ClinicalTrials.gov Identifier: NCT05668624.