Figure 7
Effect modification by regional air pollution in the relationship between personal NO 2 and O 3 and SDNN. All models are adjusted for ambient temperature during exercise, mean heart rate during exercise, and alcohol/caffeine consumption in the past 24-hours. Regression coefficients reflect interquartile range increases in exposure. All models are mutually adjusted for all other air pollutants. The high/low cut points were 11.5 μg/m3 for 24-hour PM2.5, 13.5 μg/m3 for 5-day PM2.5, 6.59 ppb for 5-day NO2, and 26.47 ppb for 5 day O3.