Fig. 2.
Pooled associations between air pollutants and total cardiovascular disease morbidity. Excess risks (ERs) are for an increase of 10 μg/m3 of particulate matter, 0.1 ppm of CO, and 10 ppb of other gaseous pollutants. I2 statistic represents the proportion of total variation between effect estimates due to heterogeneity. The p-value is based on Cochran's Q test.