How is Iowa City landfill fire affecting air quality?

Air quality remains a concern with the three-day Iowa Arts Festival approaching and black smoke continuing to billow from the fire at the Iowa City Landfill. And while breathing smoke from any fire can be harmful, health officials say the landfill fire doesn't pose an elevated cause for concern.

Doug Beardsley, director of Johnson County Public Health, said the wind direction will play a role in monitoring air quality for the festival, which starts today and runs through Sunday in Iowa City.

"I want to do tests where the smoke is," he said. "I don't want to minimize the risk, but by the time it's off the landfill property, it dilutes very quickly."

Landfill staff, assisted by the University of Iowa and the State Hygienic Laboratory, continue to monitor pollutants from the fire, which has been burning since Saturday on 7.5 acres of the 200-acre landfill at 3900 Hebl Ave. It was likely started by a hot load dumped at the site and is expected to burn into next week.

Chemicals in tires

The landfill cell's drainage layer includes the equivalent of 1.3 million shredded tires, meaning the smoke contains oil and other compounds found in tires. Beardsley said two air samples taken this week in North Liberty -- sites in Coralville and Iowa City also were tested -- came in high for benzene, a chemical known to cause cancer that is present in vehicle exhaust fumes and other sources. Results also were slightly higher for toluene, a common ingredient in degreasers.

However, Beardsley said both were under levels considered "actionable" and it was unknown if the source was the smoke, higher traffic levels or other causes.

A report from the U.S. Environmental Protection Agency cites an extensive list of pollutants that can be emitted from tire fires, such as carbon monoxide, sulfur oxides and volatile organic compounds. The list also includes polynuclear aromatic hydrocarbons, dioxins, hydrogen chloride, benzene, polychlorinated biphenyls and metals such as arsenic, cadmium, nickel, zinc, mercury and chromium.

The report noted that the emissions represent significant short-term and long-term health hazards.

"Depending on the length and degree of exposure, these health effects could include irritation of the skin, eyes, and mucous membranes, respiratory effects, central nervous system depression and cancer," the report states. "Unprotected exposure to the visible smoke plume should be avoided."

Beardsley agreed that people should avoid the smoke, but he said short-term exposure likely would not cause cancer or other long-term effects.

While the report was limited to airborne emissions, the EPA also noted that liquid containing dangerous chemicals can be generated by melting tires: "These products can pollute soil, surface water, and ground water and care must be taken to properly manage these impacts as well."

As the tires burn at the landfill, they produce an oil-based liquid that's being captured in the landfill's drainage system, according to city officials. The runoff is temporarily being stored on-site as officials, in cooperation with the Iowa Department of Natural Resources, seek facilities that can process the material.

Burning itself out

The Fire Department is letting the fire burn itself out, and Geoff Fruin, assistant to the city manager, said Thursday's rain could actually impede progress on that front.

"It's a bit counter-intuitive, but the rain could slow the burn down a bit, hamper that effort and prolong the burn," he said.

Fruin said city officials are communicating with organizers of the Iowa Arts Festival, but he didn't expected the fire to pose any problems.

He and Beardsley reiterated the warnings issued since the fire began:

• Exposure to the smoke plume should be avoided as much as possible.
• People with asthma, heart conditions or other health issues; pregnant women; and the young and elderly should stay indoors with outside air sources closed off.
• People also should avoid outdoor activities, such as exercising, if the smoke plume is present.