Brief exposure to air pollution particles triggers childhood lung infections, study conducted in Utah finds

SALT LAKE CITY -- A new study indicates that even the briefest exposure to tiny pollution-causing particles is associated with Acute Lower Respiratory Infections in young children in Utah.

According to a press release from Intermountain Healthcare, the study focuses on airborne fine particulate matter PM 2.5, which are pollution-causing particles about 3 percent of the diameter of a human hair.

The press release indicates that increases in PM 2.5 levels led to increased doctors visits for those lung infections.

The research conducted by a team from Intermountain Healthcare, Brigham Young University and the University of Utah involved more than 100,000 patients and is the largest study of its kind, the release states. The findings were published online Friday in the American Journal of Respiratory and Critical Care Medicine, which is an American Thoracic Society journal.

“The most important finding of this study is that infectious processes of respiratory disease may be influenced by particulate matter pollution at various levels,” said lead author Benjamin Horne, PhD, director of cardiovascular and genetic epidemiology at the Intermountain Medical Center Heart Institute in Salt Lake City. “The exact biological implications of the study’s findings require further investigation.”

Researchers studied 146,397 patients treated for ALRI between 1999 and 2016 at Intermountain facilities across the Wasatch Front region. Researchers found ALRI was associated with elevated levels of PM 2.5 in both children and adults—even in newborns and toddlers up to age 2, a group that represented 77% of those with an ALRI diagnosis.

The release states that nearly 60 percent of U.S. children live in counties with PM 2.5 concentrations above the air quality standards.

This study was conducted along the Wasatch Front, where average daily PM 2.5 levels are lower than places like Los Angeles and New York. However, the topography of the region means air pollution may become trapped in high mountain valleys, particularly during inversions.

Those conditions can create sharp increases in PM 2.5 levels that reach the unhealthy range of greater than 35 micrograms per cubic meter, though sometimes the levels approach 100 micrograms per cubic meter.

According to the findings, Bronchiolitis, "a condition in which small breathing tubes in the lungs called bronchioles become infected and clogged with mucus" is the most common form of ALRI found in children.

“Overall, it took about 2-3 weeks for the ALRI hospitalizations or clinic visits to occur in this study after the rapid rise in PM2.5 had been observed,” said Dr. Horne.

Among those studied there were 17 children ages 0-2 who died within 30 days of an ALRI diagnosis. There were nine deaths among children 3-17 years old and 81 adult deaths within 30 days of an ALRI diagnosis.

The press release states that motor vehicles contribute about 48 percent of emissions that lead to the formation of fine particulates, while small industries like gas stations and dry cleaners—along with home heating—account for about 39 percent. Large manufacturing accounts for about 13 percent.

“The practical implications for prevention of ALRI and amelioration of symptoms include that when an acute increase in the level of PM2.5 occurs, people may be able to prevent infections or decrease ALRI symptom severity or duration by reducing their exposure to the air pollution,” said Dr. Horne. “Furthermore, a substantial elevation in PM2.5 may also serve as a nudge that reminds or alerts people to avoid areas and activities where other people may share an infection with them, to not touch their face with dirty hands, to be vigilant about washing their hands when reasonably possible or prudent, and to engage in other preventive behaviors that are known to reduce infection risk.”