Figure 4.

Ischemic heart disease (IHD) risk ratios for the oxidative potential of water-soluble ${\mathrm{PM}}_{2.5}$ as measured by the DTT assay (${\text{OP}}^{\text{DTT}}$) and other pollutant measures in bipollutant models, for (A) lag 0–2 pollutants and (B) lag 0 pollutants. Risk ratio for ${\text{OP}}^{\text{DTT}}$ (diamond markers) are per interquartile range (IQR) of ${\text{OP}}^{\text{DTT}}$ ($0.21{\text{nmol}/\text{min}/\mathrm{m}}^3$); risk ratio for all other pollutant measures (circular markers) are per IQR of that particular pollutant. Note: $\mathrm{CO}$, carbon monoxide; $\mathrm{Cu}$, copper; $\mathrm{EC}$, elemental carbon; $\mathrm{Fe}$ iron; $\mathrm{Mn}$, manganese; ${\text{NH}}_4$, ammonium; ${\text{NO}}_2$, nitrogen dioxide; ${\text{NO}}_3$, nitrate; $\mathrm{OC}$, organic carbon; ${\mathrm{O}}_3$, ozone; ${\mathrm{PM}}_{2.5}$, fine particulate matter; ${\text{SO}}_2$, sulfur dioxide; ${\text{SO}}_4$, sulfate. $\mathrm{EC}$, ${\text{NH}}_4$, ${\text{NO}}_3$, $\mathrm{OC}$, ${\text{SO}}_4$, $\mathrm{Mn}$, $\mathrm{Fe}$, and $\mathrm{Cu}$ are components of ${\mathrm{PM}}_{2.5}$.