Age and size of smoke is increasing the toxicity of our smoke episode

Western Washington has been under a dense blanket of smoke for more than a week. Puget Sound Clean Air Agency says the smoke layer Tuesday has been around 3500 ft thick.

Washington toxicologists say the list of harmful chemicals in wildfire smoke is a long one, but what makes it more toxic in Western Washington is the long-distance the smoke has traveled from Eastern Washington. The long journey ages the smoke as it interacts with other chemicals.

"Aged smoke is more harmful probably than younger smoke up to a point. It becomes more oxidized from oxygen in the atmosphere as it reacts and travels for days. Those oxidized, organic chemicals in the smoke do make it a bit more toxic than it would be if it weren't so old," said Matthew Kadlec, a toxicologist at the Washington Department of Ecology.

The small size of the particles allows the smoke to travel thousands of miles. Smoke and dust is being observed in almost every state in the US. The Washington Department of Health says the small size of the particles makes it more dangerous to our health.

"We're concerned about PM2.5 in particular because those particles are small enough that they can get in circulation to all different parts of the body and cause a number of types of health effects that are of concern," said epidemiologist Julie Fox.

Harborview Medical Center says its seen an increase of three patients per day with breathing issues. Many of them had underlying health conditions like asthma and lung disease, but Kadlec says even healthy people can have problems, especially as we enter the colder months.

"There's research coming out that shows in the winters after wildfire smoke episodes, people have higher incident rates of respiratory infections and more severe symptoms if they do get respiratory infection like flu," said Kadlec.

Stay indoors as much as possible, keep the air clean inside your home, and monitor the forecast.