Associations between Ambient Fine Particulate Oxidative Potential and Cardiorespiratory Emergency Department Visits

Abstract

Background:Oxidative potential (OP) has been proposed as a measure of toxicity of ambient particulate matter (PM).Objectives:Our goal was to address an important research gap by using daily OP measurements to conduct population-level analysis of the health effects of measured ambient OP.Methods:A semi-automated dithiothreitol (DTT) analytical system was used to measure daily average OP (OPDTT) in water-soluble fine PM at a central monitor site in Atlanta, Georgia, over eight sampling periods (a total of 196 d) during June 2012–April 2013. Data on emergency department (ED) visits for selected cardiorespiratory outcomes were obtained for the five-county Atlanta metropolitan area. Poisson log-linear regression models controlling for temporal confounders were used to conduct time-series analyses of the relationship between daily counts of ED visits and either the 3-d moving average (lag 0–2) of OPDTT or same-day OPDTT. Bipollutant regression models were run to estimate the health associations of OPDTT while controlling for other pollutants.Results:OPDTT was measured for 196 d (mean=0.32 nmol/min/m3, interquartile range=0.21). Lag 0–2 OPDTT was associated with ED visits for respiratory disease (RR=1.03, 95% confidence interval (CI): 1.00, 1.05 per interquartile range increase in OPDTT), asthma (RR=1.12, 95% CI: 1.03, 1.22), and ischemic heart disease (RR=1.19, 95% CI: 1.03, 1.38). Same-day OPDTT was not associated with ED visits for any outcome. Lag 0–2 OPDTT remained a significant predictor of asthma and ischemic heart disease in most bipollutant models.Conclusions:Lag 0–2 OPDTT was associated with ED visits for multiple cardiorespiratory outcomes, providing support for the utility of OPDTT as a measure of fine particle toxicity. https://doi.org/10.1289/EHP1545

The acidity of atmospheric particles and clouds

“…One reason for this could be that aerosol acidity influences solubilization and the concentrations of toxic forms of trace species, such as transition and heavy metals, that have been linked to negative health effects (Kelly and Fussell, 2012;Lippmann, 2014;Rohr and Wyzga, 2012;Chen and Lippmann, 2009;Frampton et al, 1999). Transition metal ions (TMIs), such as soluble Cu and Fe from acid dissolution, contribute significantly to the oxidative potential of particles Pöschl and Shiraiwa, 2015), which has been linked to cardiorespiratory emergency department visits with a stronger association than PM 2.5 mass (Abrams et al, 2017;Bates et al, 2015). Ye et al (2018) report a strong association between soluble Fe, which is modulated by particle acidity and aerosol water content, and cardiovascular endpoints.…”

“…The bisulfate anion is often more abundant than the sulfate ion in fine particles; however, TSO 4 is often conceptualized has having an effective charge of negative 2. Adams et al, 1999) has been suggested, defined as…”

“…As West et al (1999) showed, the GR still requires complementary thermodynamic modeling to robustly explore the PM response for large sulfate reductions. Other applications of the GR include calculation of the GR as a function of altitude (Adams et al, 1999); characterization of the sulfate-nitrateammonia-water aerosol system in the context of natural and transboundary pollution over the US (Park et al, 2004); and exploration of the sensitivity of aerosol nitrate to changes in temperature, RH, TNH 4 , TNO 3 , and sulfate for Pittsburgh (Takahama et al, 2004). In addition, Blanchard and Hidy (2003) considered the GR in a study of the response of nitrate to changes in TNH 4 , TNO 3 , and sulfate in the southeastern US.…”

Comparison between five acellular oxidative potential measurement assays performed with detailed chemistry on PM<sub>10</sub> samples from the city of Chamonix (France)

“…The AA assays would be more specific to the oxidative potential of transition metals (Godri et al, 2011;Yang et al, 2014), but ascorbic acid is known to react with organics such as quinones (Shang et al, 2012;Visentin et al, 2016). All of these assays have shown some correlations with health outcomes in epidemiological studies (Abrams et al, 2017;Bates et al, 2015;Fang et al, 2016;Strak et al, 2017;Weichenthal et al, 2016a, b;Yang et al, 2016). Detailed PM 10 characterization was performed in parallel, by analyzing up to 130 chemical species that incorporated a broad array of organic species and trace elements (Chevrier, 2016).…”

Review of PM Oxidative Potential Measured with Acellular Assays in Urban and Rural Sites across Italy

“…In recent years, the oxidative potential (OP) of particulate matter (PM) has been proposed as a biologically relevant metric to be associated with a number of health endpoints and biomarkers of toxic effects in humans [1][2][3][4][5][6][7]. It is based on the increasing consensus that the oxidative stress is an important mechanism of human toxicity related to exposure to atmospheric aerosols.…”