Figure 3From: Cardiac effects of seasonal ambient particulate matter and ozone co-exposure in ratsMean change in Heart rate (HR) from pre-exposure values during summer and winter exposures. HR values for each animal at each time point during exposure or after exposure were subtracted from corresponding time-matched pre-exposure baseline data, which was recorded while the animals were either in the chamber (for “during exposure” data) or in their home cages (for “after exposure” data). Values represent mean change in HR in beats per minute ± standard error of the mean (n = 6). a - significantly less than filtered air control (p < 0.05). b - significantly greater than filtered air control (p < 0.05).Back to article page