State Study Links Air Pollution to Increased Medical Visits

Rising air pollution leads to increases in strokes, respiratory illnesses and heart conditions, according to the results of federally funded study announced on June 18.

The study, conducted in north Idaho, compared days of increased air pollution to people's visits to doctors, acute care clinics, hospitals and other healthcare providers. Data on healthcare encounters over a two-year period was collected from major health insurance companies and compared to air quality data collected by the Idaho Department of Environmental Quality (IDEQ). The study originally was intended to investigate the relationship between field burning in north Idaho and health effects, but was modified to study air pollution in general due to the low number of burn days during the two-year study period.

"This analysis is unique because of the type of data collected and used," said Jim Vannoy, manager of the Environmental Health Education and Assessment Program in the Idaho Department of Health and Welfare's Division of Health. "While there are more than 2,000 studies that used hospital admissions or mortality data to show how air pollution affects health, this study includes a broader selection of healthcare facilities, such as urgent care clinics, private practice physicians and specialty medical clinics, along with hospitals."

Vannoy said that by including a wider range of medical care facilities, study results are more reliable than those studies only using hospital or mortality data. "From this study we learned that high levels of air pollution markedly increased people's need for medical care for cardiac, stroke and respiratory conditions," he said.

Increases in coarse particulate matter (particulates larger than 2.5 micrometers and smaller than 10 micrometers in diameter) were associated with a 33-percent increase in medical visits for acute. The increases in air pollution also were associated with a 13-percent increase in acute lower respiratory healthcare encounters, such as pneumonia and bronchitis, and a 10-percent increase in acute upper respiratory visits, for illnesses such as sinus infections and laryngitis.

"For people who have suffered a stroke or have respiratory or cardiac conditions, the information from this study shows how important it is for them to avoid or decrease the amount of time outdoors when air quality is poor," Vannoy said.

The study can be accessed in PDF format at For more information on particulate matter, visit

This article originally appeared in the 06/01/2007 issue of Environmental Protection.

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