Figure 1.
The percent change in adverse effects (increase or decrease) associated with a 10-ppb increase in ozone (O3) exposure (controlled for particulate matter ⩽2.5 μm in aerodynamic diameter (PM2.5) and O3 loss exposure) and a 10-ppb increase in O3 loss exposure (controlled for PM2.5 and O3 exposure) in the Children study. Only biomarkers that show a statistically significant association (P value < 0.05) with 12-hour, 24-hour (at any of lag days), or 2-week average O3 or O3 loss exposure are shown. If multiple significant or nonsignificant associations were found, the associations with the smallest P value are shown in the figure. Significant and adverse associations between biomarkers and O3 loss exposures: FeNO (fractional exhaled nitric oxide) (12-h, 24-h, lag Day 2, 2-wk), Z5 (24-h), X5 (24-h), Fres (24-h, lag Day 1), FEV1/FVC: (12-h). A positive value (y-axis) indicates an adverse effect, and a negative value indicates a beneficial effect. Fixed-effect covariates: Sex, age, ambient temperature and humidity, baseline eosinophil number (/μl), upper airway tract infection-like symptoms (binary), inhaled corticosteroid usage (binary), asthma exacerbation (binary). A sensitivity analysis for FEV1/FVC: and FeNO by adjusting for height and weight showed similar results. Participant baseline characteristics: Age (mean [SD] = 7.8 [2.3], range = 5–13, and unit = years), sex (17 males and 26 females), eosinophil count (mean [SD] = 379 [265], range = 80–1260, and unit = /μl). CI = confidence interval; Fres = resonant frequency; MDA = malondialdehyde; X5 = reactance at 5 Hz; Z5 = impedance at 5 Hz.