Choking on Metal Particle Emissions

Samantha Zeitz

As society works towards reducing vehicle pollution, one emission contributor has been overlooked – brake and tire dust.

The function of brakes and tires has been found to launch metal particle emissions into the air. A study published in Environmental Science & Technology revealed how metal particle emissions can cause serious respiratory issues. Metals such as copper, iron and manganese react with acidic sulfate-rich particles that are already present in the air, creating a toxic aerosol.

Athanasios Nenes is a professor and Georgia Power Scholar in the School of Earth & Atmospheric Sciences, as well as in the School of Chemical & Bimolecular Engineering. She told science daily that many people assume acidic sulfate burns your lung lining. However, there isn’t enough acid in the air to actually have that effect. A study sponsored by the National Science Foundation and the U.S. Environmental Protection Agency showed how the sulfate made the metal emissions soluble and a threat to respiratory health.

Researchers conducted tests to determine chemical content, size distribution, and acidity of sampled particulate matter. Samples were gathered in two areas in Atlanta. One was taken close to a major interstate highway and the other from an urban area, 420 meters from the roadway. They found that the sulfate particles were similar in size to the metal particles, allowing the sulfate to turn the metal into soluble form within a few hours or days.

The next test was to see the harm this aerosol mixture would have on cellular organisms. Researchers at Georgia Tech and Emory University found a link between the inhalation of the soluble metal particle emissions and hospital admissions in Atlanta for asthma and wheezing. Because the sulfate dissolves the metal into soluble form, it allows those particles to travel from your airway into your blood stream to cause problems all throughout your body.