# PM2.5 Metals, Oxidative Potential, Exposure, and Risk Assessment (PM OPERA): A National Morbidity and Mortality Study

> **NIH NIH R56** · COLORADO STATE UNIVERSITY · 2024 · $676,077

## Abstract

Project Summary
Outdoor fine particulate air pollution (PM2.5, particles with aerodynamic diameter < 2.5 𝜇m) is a leading cause
of global morbidity and mortality, contributing to millions of premature deaths each year. Climate change will
worsen the burden of disease from PM2.5 in the coming decades, with severe effects felt by those of low
socioeconomic status and from underrepresented racial and ethnic groups. Little is known about the extent to
which different US populations may experience “different kinds of particles” with respect to PM2.5 composition
and overall toxicity. Recent research suggests that the combined transition metal and sulfur content of PM2.5
may influence the respiratory and cardiovascular health risks that result from acute and chronic exposure.
Oxidative stress is an important mechanism linked to the cardiorespiratory health effects of PM2.5 and several
recent studies have incorporated measures of PM2.5 oxidative potential (a measure of the ability of particles to
promote oxidative stress in cells and tissues) as a complementary metric to PM2.5 mass. Importantly, several of
these studies have noted stronger associations between outdoor PM2.5 mass concentrations and both acute
and chronic health outcomes when the PM2.5 oxidative potential was elevated. We hypothesize that particle
acidity increases the bioavailability of PM metals, allowing them to participate in redox reactions that contribute
to oxidative stress and potential adverse cardiovascular and respiratory health outcomes.
The objective of this research is to determine how spatial and temporal variations in PM2.5 composition and
oxidative potential may modify the strength of associations between PM2.5 mass concentrations and
cardiorespiratory morbidity/mortality. We will deploy a low-cost measurement network to quantify PM2.5
oxidative potential on a national scale. Collected samples will be analyzed for trace elements and oxidative
potential (Aim 1). With these data we will conduct a national-scale time-stratified case-crossover study of daily
variations in outdoor PM2.5 mass concentrations and acute cardiorespiratory morbidity among Medicare
enrollees (Aim 2). Specifically, this analysis will evaluate how monthly variations in PM2.5 components and
oxidative potential across the US modify the strength of associations between day-to-day changes PM2.5 mass
concentrations and acute health outcomes (acute myocardial infarction, ischemic heart disease, congestive
heart failure, chronic obstructive pulmonary disease, and asthma) among potentially sensitive subsets of the
US population. Finally, we will conduct a cohort study in the Medicare cohort (Aim 3) to evaluate how spatial
variations in annual average estimates of PM2.5 components and oxidative potential across the US modify the
strength of associations between yearly changes PM2.5 mass concentrations and chronic health outcomes
among potentially sensitive subsets of the US population. We will also estimate the ...

## Key facts

- **NIH application ID:** 11141315
- **Project number:** 1R56ES035767-01
- **Recipient organization:** COLORADO STATE UNIVERSITY
- **Principal Investigator:** John Volckens
- **Activity code:** R56 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2024
- **Award amount:** $676,077
- **Award type:** 1
- **Project period:** 2024-09-01 → 2025-07-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/11141315

## Citation

> US National Institutes of Health, RePORTER application 11141315, PM2.5 Metals, Oxidative Potential, Exposure, and Risk Assessment (PM OPERA): A National Morbidity and Mortality Study (1R56ES035767-01). Retrieved via AI Analytics 2026-05-24 from https://api.ai-analytics.org/grant/nih/11141315. Licensed CC0.

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