Short-term exposure to ambient ozone and inflammatory biomarkers in cross-sectional studies of children and adolescents: Results of the GINIplus and LISA birth cohorts.

Background: While exposure to ambient particulate matter (PM) and nitrogen dioxide (NO2) is thought to be associated with diseases via inflammatory response, the association between exposure to ozone, an oxidative pollutant, and inflammation has been less investigated.Aim: We analyzed associations between short-term exposure to ozone and three inflammatory biomarkers among children and adolescents.Methods: These cross-sectional analyses were based on two follow-ups of the GINIplus and LISA German birth cohorts. We included 1330 10-year-old and 1591 15-year-old participants. Fractional exhaled nitric oxide (FeNO) and high-sensitivity C-reactive protein (hs-CRP) were available for both age groups while interleukin (IL)-6 was measured at 10 years only. Maximum 8-h averages of ozone and daily average concentrations of NO2 and PM with an aerodynamic diameter <10 mu m (PM10) were adopted from two background monitoring stations 0 (same day), 1, 2, 3, 5, 7, 10 and 14 days prior to the FeNO measurement or blood sampling. To assess associations, we utilized linear regression models for FeNO, and logistic regressions for IL-6 and hs-CRP, adjusting for potential covariates and co-pollutants NO2 and PM10.Results: We found that short-term ozone exposure was robustly associated with higher FeNO in adolescents at age 15, but not at age 10. No consistent associations were observed between ozone and IL-6 in children aged 10 years. The relationship between hs-CRP levels and ozone was J-shaped. Relatively low ozone concentrations (e.g., <120 mu g/m(3)) were associated with reduced hs-CRP levels, while high concentrations (e.g., >= 120 mu g/m(3)) tended to be associated with elevated levels for both 10- and 15-year-old participants.Conclusions: Our study demonstrates significant associations between short-term ozone exposure and FeNO at 15 years of age and J-shaped relationship between ozone and hs-CRP. The finding indicates that high ozone exposure may favor inflammatory responses in adolescents, especially regarding airway inflammation