STUDY: New Research Links Higher Street-Level Traffic-Related Air Pollution with Increased Emergency Room Costs

(Washington, D.C. – August 9, 2022) A new study published in the journal Atmospheric Environment finds that long-term exposure to traffic-related air pollution is associated with higher health care costs for older adults. 

Scientists from Environmental Defense Fund and Kaiser Permanente Division of Research analyzed data from their joint study of block-by-block study of air pollution in Oakland, CA as well as five years of electronic health records of more than 25,000 members of Kaiser Permanente Northern California ages 65 and over. The study found that even small differences in concentrations of nitrogen dioxide, a key traffic-related air pollutant, were associated with increased health care costs. 

Specifically, living in an area with concentrations of nitrogen dioxide that are 5.9 parts per billion higher than another area was associated with a 22% increase in emergency room costs and 5% increase in outpatient costs. Among residents with existing cardiovascular disease, the effect was more pronounced. Higher air pollution was associated with 7% higher total annual direct health care costs and 23% higher emergency room costs compared to a similar population with lower pollution exposures.

This study is the first to empirically assess the invisible impact of long-term exposure to traffic-related air pollution on direct total health care costs. Air pollution is the biggest environmental health risk globally, resulting in heart and lung disease, strokes, diabetes, emergency room visits, hospital admissions and even death. Nitrogen dioxide, a key traffic-related air pollutant, is primarily generated from truck, bus and vehicular exhaust, and this study builds upon a growing body of evidence indicating that long-term exposure to this pollutant is associated with poor health outcomes. 

The study linked air quality data, gathered from monitors affixed to Google Street View cars that repeatedly measured block-by-block air pollution concentrations, with residential addresses. To calculate comprehensive health care costs, researchers analyzed detailed records of health care costs, including annual total health care, inpatient, outpatient, emergency room and pharmacy costs. 

“Street-level air quality data shines a light on pollution hotspots, enabling a better understanding of traffic-related air pollution's impacts on health and associated costs within cities,” said Ananya Roy, EDF senior health scientist and a co-author of the study. “We know reducing traffic-related air pollution presents an opportunity to protect public health. This new research suggests it could also help substantially reduce health care costs.”

“Nearly 80% of the U.S. population lives in an urban area, and our research adds to the evidence that air pollution in these areas has numerous recognized adverse health impacts as well as economic ones,” said senior author Stephen Van Den Eeden, a research scientist at the Kaiser Permanente Division of Research. “We believe analyses like ours can help us to understand the full health and economic impacts of air pollution.”