The South Willamette Valley consistently ranks high nationally for levels of air pollution. According to the American Lung Association, Eugene-Springfield was the 14th worse in the country for “short-term particle pollution” in 2013.
Air pollution is a complex mixture of chemicals and particulate matter –so complex, scientists still don’t know exactly what’s in the air we breathe. But now they’re one step closer.
Researchers at Oregon State University have discovered fourteen new chemical compounds. The mixtures can be hundreds of times more likely to cause mutations than other pollutants.
It all started in Beijing at the Summer Olympics of 2008. Concerns about the high levels of air pollution were a major storyline of the games. That created the opportunity for OSU Chemistry Professor Staci Simonich to begin doing air testing in China.
Simonich: “The first paper my laboratory published on the air quality and particulate matter in Beijing before, during, after the Olympics was a little controversial.”
Despite this, Simonich was able to continue work in the country, figuring out the chemical fingerprint of air pollution and using that information a bit closer to home.
Simonich has an air monitoring station at the top of Mt. Bachelor near Bend. There, she is able to detect if air pollution in China is making its way across the Pacific Ocean to Oregon. Short answer: it is.
Simonich: “Some of the compounds that we found that were transported were Polycyclic Aromatic Hydrocarbons.”
…Or PAHs. Quick science lesson: That's the name for a group of chemical compounds. Many are classified as carcinogenic and mutagenic by the Environmental Protection Agency. They’ve been shown to cause things like tumors and birth defects in lab mice, and a growing body of research suggests serious ill effects on humans as well, including cancer. So they’re regulated by the government.
PAHs are naturally occurring – and happen whenever organic material is burned.
Simonich: “Anytime there was a forest fire or a prairie fire or even to some degree even a volcanic eruption if there’s carbon present… For eons, since the advent of fire, there’s been PAHs.”
Of course, since humans started burning fossil fuels like coal and oil, the amount of PAHs in the atmosphere has dramatically increased. And PAHs are even being produced in the home.
On the barbecue. When meat, and in particular fat, is charred on a grill – like I’m doing right now – PAHs are produced. So I’m breathing in all kinds of PAHs right now – not a pleasant thought.
Simonich: “We tend to think a lot about particles in air, and that is important - in our lungs. But largest dose of our exposure is via diet.”
Wait, does that mean I should put down my tongs right now?
Simonich: “No, I’m a firm believer in everything in moderation…"
Through air monitoring in Oregon, Simonich found high concentrations of PAHs riding on the backs of particulate matter coming over from Asia.
Simonich: “And the fact that they’re on very fine particles – less than 2.5 microns – means that they can be stuck in the lungs once you breathe them in. And then we started to think other pollutants are also transported in this mix. Could there be chemistry happening in Asia? Reactions that are occurring there or in transit across the Pacific Ocean that may be modifying them chemically?”
The other pollutant is the highly reactive nitrogen dioxide, commonly found in car exhaust. With computer modeling, the scientists predicted that the nitrogen dioxide and the PAHs would combine. Then in a lab, they recreated atmospheric conditions where both chemicals were present and tested the samples.
Simonich: “One sample working on it continuously could take a week or so, between having the sample, extracting it, purifying it…”
Four to five-hundred samples later… The predictions were correct. The OSU team found fourteen never-before-detected compounds collectively called High Molecular Weight Nitro-PAHs
But they didn’t stop there. Back at the lab at Oregon State, they asked another question: How likely are these new compounds to cause mutations to genetic material?
Using further tests, they found that the Nitro-PAHs are up to 467 times more mutagenic than the original PAHs on their own.
So to give you a picture of this: imagine PAHs are tiny piranha … swimming out there in the air. If you encounter enough of them, you may begin to sustain long-term damage.
Now imagine some of the Piranhas are carrying chainsaws. Those are the Nitro-pAHs. And the potential for damage is much greater.
But currently those chainsaw-wielding Piranhas have only been detected in a lab at Oregon State.
Simonich: “Our next step now is to go into our air samples from Beijing and air samples from Mt. Bachelor, and various different diesel exhaust, and maybe even grilled meat, and start to look in those different parts of the environment to see where those chemicals may be. And the truth is no one has ever looked for them before.”
That’s because, prior the discovery of Simonich and her team, no one even knew they existed.
The Oregon State research was published in the journal Environmental Science and Technology.