mutagenic « The Erlenmeyer Flask

Originally aired on KLCC 89.7 | By Jes Burns | Used with Permission

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.

PAH's — Dr. Staci Simonich, Professor in Environmental and Molecular Toxicology in her office at Oregon State University (Credit Jes Burns)

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.

One of the labs on the OSU campus where PAH research occurs. (Credit: Jes Burns)

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.

Click here to access the research.

by David Stauth

1/6/2014 – Reprinted from News & Research Communications

CORVALLIS, Ore. – Researchers at Oregon State University have discovered novel compounds produced by certain types of chemical reactions – such as those found in vehicle exhaust or grilling meat – that are hundreds of times more mutagenic than their parent compounds which are known carcinogens.

These compounds were not previously known to exist, and raise additional concerns about the health impacts of heavily-polluted urban air or dietary exposure. It’s not yet been determined in what level the compounds might be present, and no health standards now exist for them.

The findings were published in December in Environmental Science and Technology, a professional journal.

The compounds were identified in laboratory experiments that mimic the type of conditions which might be found from the combustion and exhaust in cars and trucks, or the grilling of meat over a flame.

“Some of the compounds that we’ve discovered are far more mutagenic than we previously understood, and may exist in the environment as a result of heavy air pollution from vehicles or some types of food preparation,” said Staci Simonich, a professor of chemistry and toxicology in the OSU College of Agricultural Sciences.

“We don’t know at this point what levels may be present, and will explore that in continued research,” she said.

The parent compounds involved in this research are polycyclic aromatic hydrocarbons, or PAHs, formed naturally as the result of almost any type of combustion, from a wood stove to an automobile engine, cigarette or a coal-fired power plant. Many PAHs, such as benzopyrene, are known to be carcinogenic, believed to be more of a health concern that has been appreciated in the past, and are the subject of extensive research at OSU and elsewhere around the world.

The PAHs can become even more of a problem when they chemically interact with nitrogen to become “nitrated,” or NPAHs, scientists say. The newly-discovered compounds are NPAHs that were unknown to this point.

This study found that the direct mutagenicity of the NPAHs with one nitrogen group can increase 6 to 432 times more than the parent compound. NPAHs based on two nitrogen groups can be 272 to 467 times more mutagenic. Mutagens are chemicals that can cause DNA damage in cells that in turn can cause cancer.

For technical reasons based on how the mutagenic assays are conducted, the researchers said these numbers may actually understate the increase in toxicity – it could be even higher.

These discoveries are an outgrowth of research on PAHs that was done by Simonich at the Beijing Summer Olympic Games in 2008, when extensive studies of urban air quality were conducted, in part, based on concerns about impacts on athletes and visitors to the games.

Beijing, like some other cities in Asia, has significant problems with air quality, and may be 10-50 times more polluted than some major urban areas in the U.S. with air concerns, such as the Los Angeles basin.

An agency of the World Health Organization announced last fall that it now considers outdoor air pollution, especially particulate matter, to be carcinogenic, and cause other health problems as well. PAHs are one of the types of pollutants found on particulate matter in air pollution that are of special concern.

Concerns about the heavy levels of air pollution from some Asian cities are sufficient that Simonich is doing monitoring on Oregon’s Mount Bachelor, a 9,065-foot mountain in the central Oregon Cascade Range. Researchers want to determine what levels of air pollution may be found there after traveling thousands of miles across the Pacific Ocean.

This work was supported by the National Institute of Environmental Health Sciences and the National Science Foundation. It’s also an outgrowth of the Superfund Research Program at OSU, funded by the NIEHS, that focuses efforts on PAH pollution. Researchers from the OSU College of Science, the University of California-Riverside, Texas A&M University, and Peking University collaborated on the study.

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About Oregon State University: OSU is one of only two U.S. universities designated a land-, sea-, space- and sun-grant institution. OSU is also Oregon’s only university to hold both the Carnegie Foundation’s top designation for research institutions and its prestigious Community Engagement classification. Its more than 26,000 students come from all 50 states and more than 90 nations. OSU programs touch every county within Oregon, and its faculty teach and conduct research on issues of national and global importance.

1/7/2014 – See article on Science Daily

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OSU Scientists Discover 14 New PAHs

New Compounds Discovered That Are Hundreds of Times More Mutagenic

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