Short-Term Particulate Matter, Ultrafine Particles, and Blood Pressure among Children of the CorPuScula Study in Munich, Germany

Abstract

BACKGROUND AND AIM: Short-term changes in particulate matter (PM) have been linked to blood pressure, but limited evidence exists on effects among children and for ultrafine particle (UFP) exposures. METHODS: We used data from 50 children (ages 6-10) in the German CorPuScula study, in which children attended up to 30 school health examinations in 2001 and 2002. Systolic and diastolic blood pressure (SBP and DBP, respectively; mmHg) were collected at each examination after children had rested for at least 5 minutes. PM10 (diameter ≤10 µm; µg/m3) and PM2.5 (diameter ≤2.5 µm; µg/m3) levels were measured at school using a low volume sampler for the entire study period, and UFPs (n/mL) were measured for six months using a particle counter. All exposures were evaluated for same-day working-hours (9:00-21:00) as well as one- and two-day lags, with UFPs also assessed for the 1-, 3-, 12-, and 24-hours prior to examination. Associations between air pollutants and blood pressure were evaluated using mixed linear regression models with a random participant intercept and adjusted for weekday as well as study day and physiological equivalent temperature index using natural cubic splines. Multipollutant models were conducted adjusting for centrally-monitored NO2. RESULTS:For the PM data (nobs=1,079; average 22 observations/child), median daily PM2.5 levels were 12.7 µg/m3. In the UFP data (nobs=420; average 8 observations/child), median daily UFP exposures were 21,544 particles/mL. We observed positive associations between PM and SBP that attenuated slightly upon adjustment for NO2, with strongest associations for 2-day lags (e.g., 1.45 mmHg [95% Confidence Interval: 0.78, 2.11] increase in SBP per 13.4 µg/m3 increase in PM2.5). PM10 was weakly inversely associated with DBP. No associations between UFP exposures and either outcome were apparent. CONCLUSIONS:While positive associations were observed between PM and SBP, we observed no evidence that UFP exposure influences blood pressure in children. KEYWORDS: Children's environmental health, Short-term exposure, Air pollution, Cardiovascular diseases, Multi-pollutant