Estimating Acute Cardiovascular Effects of Ambient [Formula: see text] Metals

BACKGROUND: Few epidemiologic studies have investigated health effects of water-soluble fractions of [Formula: see text] metals, the more biologically accessible fractions of metals, in their attempt to identify health-relevant components of ambient [Formula: see text]. OBJECTIVES: In this study, we estimated acute cardiovascular effects of [Formula: see text] components in an urban population, including a suite of water-soluble metals that are not routinely measured at the ambient level. METHODS: Ambient concentrations of criteria gases, [Formula: see text] , and [Formula: see text] components were measured at a central monitor in Atlanta, Georgia, during 1998–2013, with some [Formula: see text] components only measured during 2008–2013. In a time-series framework using Poisson regression, we estimated associations between these pollutants and daily counts of emergency department (ED) visits for cardiovascular diseases in the five-county Atlanta area. RESULTS: Among the [Formula: see text] components we examined during 1998–2013, water-soluble iron had the strongest estimated effect on cardiovascular outcomes [[Formula: see text] (95% CI: 1.005, 1.019), per interquartile range increase ([Formula: see text])]. The associations for [Formula: see text] and other [Formula: see text] components were consistent with the null when controlling for water-soluble iron. Among [Formula: see text] components that were only measured during 2008–2013, water-soluble vanadium was associated with cardiovascular ED visits [[Formula: see text] (95% CI: 1.000, 1.025), per interquartile range increase ([Formula: see text])]. CONCLUSIONS: Our study suggests cardiovascular effects of certain water-soluble metals, particularly water-soluble iron. The observed associations with water-soluble iron may also point to certain aspects of traffic pollution, when processed by acidifying sulfate, as a mixture harmful for cardiovascular health. https://doi.org/10.1289/EHP2182