Just how dangerous is that smoke we're breathing from regional wildfires?

Just how dangerous is that smoke we're breathing from regional wildfires?

Most people shouldn't suffer long-term effects from the air pollution, even if they don't wear a mask, said Dr. Somnath Ghosh, a pulmonary and critical care specialist at Asante Rogue Regional Medical Center in Medford.

He said he doesn't wear a mask, noting that most people without respiratory or heart problems should feel only short-term problems from exposure to the smoke, caused by five regional fires that together have burned at least 65,000 acres in southwestern Oregon.

"I would not say that a mask was necessary," Ghosh said. "If you're involved in strenuous or persistent activity, it wouldn't hurt to put that on."

Ghosh said the emergency room has seen an increase in patients with asthma or other respiratory conditions that have been exacerbated by the smoke.

Ghosh said a study in the 1990s looked at the rate of lung cancer in urban firefighters exposed to toxic substances on a habitual basis over many years. Long-term exposure resulted in a risk of cancer three times the national average, he said.

A few weeks or months of exposure to smoky conditions locally shouldn't carry any significant risk of long-term health problems, Ghosh said.

For those with respiratory or heart problems, they should just stay indoors as much as possible, he said.

Others are donning masks when they venture out.

"I'm wearing a mask when I go back and forth from my office to the hospital," said Grant Walker, spokesman for RRMC. "It's worse here than Shanghai."

Walker said both Asante Three Rivers Medical Center in Grants Pass and RRMC have seen a moderate increase in patients seeking medical help for ailments related to the smoke, particularly those with asthma or chronic lung illnesses.

He said the hospital is concerned that people will become acclimated to the smoke and decide to forgo wearing a mask. Health officials recommend wearing a mask that states "NIOSH N95" to filter out most of the very fine particles from wildfire smoke that travel deep into the lungs.

David Farrer, public health toxicologist with the Oregon Health Authority, said most people without respiratory or heart problems shouldn't experience long-term issues from inhaling the smoke.

"Generally speaking, an exposure to wildfire smoke for a few weeks or a couple of months is not going to increase the overall lifetime risks of cancer or asthma," he said.

Long-term exposure is considered to be at least a year, not weeks or months, Farrer said.

Despite the low risk to otherwise healthy residents, Farrer said people should be prudent and avoid going outdoors when there is heavy smoke.

"If you can hold off going on a run until after the clearing happens, it would be better," he said.

Staying indoors is generally better than wearing a mask outdoors during heavy periods of smoke, he said.

The smoke has limited some outdoor activities in the valley. The Oregon Shakespeare Festival has canceled at least two shows on its outdoor Elizabethan Stage because of smoke over the last two weeks. Administrators decide whether to cancel an outdoor show at 7 p.m. the day of performance based on air quality. See www.osfashland.org/smoke.

Reach Mail Tribune reporter Damian Mann at 541-776-4476 or dmann@mailtribune.com.