grilled meat

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.

Dr. Staci Simonich, Project 5 Leader with the OSU Superfund Research Program
Dr. Staci Simonich, Project 5 Leader with the OSU Superfund Research Program

“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 (NIEHS) and the National Science Foundation (NSF). 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.

[Credit: Oregon State University Press Release]

See video from KVAL news

Learn more about PAHs from the Superfund Research Program web site.

 

By Steven O’Connell (Student, Project 4)

SOConnell_SRPPost
Steven O’Connell sampling at the Portland Harbor Superfund Site

In the past few years, our Center has been conducting research to learn more about oxygenated polycyclic aromatic hydrocarbons (OPAHs). OPAHs are one of the degradation products of parent PAHs. OPAHs are studied because they are present in the environment and pose an unknown hazard to human health.

Although OPAHs have been measured in several samples all over the world, most analyses contained only a handful of OPAHs or used methods that may be inaccurate.  To address some of the analytical challenges measuring OPAHs, I was involved in a multi-year study: An Analytical Investigation of 24 Oxygenated-PAHs (OPAHs) using Liquid and Gas Chromatography-Mass Spectrometry.

Why is there a focus now on OPAHs?

Focus on this class of compounds has really increased in the last few years, although it’s interesting to note that there were reports of some of these compounds in the 1970’s and earlier.  There are several reasons researchers want to study these compounds.  OPAHs seem to be found in similar concentrations to the highly studied parent PAHs in a variety of samples ranging from diesel exhaust to urban air.  Additionally, not a lot is known about the toxicity of these compounds, although early evidence suggests that they may be on par with PAHs.  That’s why the OPAH research of students Andrea Knecht and Britton Goodale in Dr. Robyn Tanguay’s Lab (Project 3) has been so important.

Why measure OPAHs at the Portland Harbor Superfund Site?

It makes a lot of sense to try and measure OPAHs at Portland Harbor Superfund. PAHs have been responsible for remediation at some sites for years now, and are the precursors of OPAHs.  In some cases, remediation approaches employ ultra violet (UV) light to try and degrade PAHs and thereby cleanup that site.  However, it is possible that PAHs could degrade to OPAHs during the process.  If no one is monitoring the products of this UV treatment, the site could remain hazardous.  That’s why Norman Forsberg’s upcoming paper and Marc Elie’s work with ultra violet light in the Anderson laboratory (Project 4) is so interesting.

What still needs to be understood?  

The formation and concentration of these compounds in the environment at contaminated sites are poorly understood. It is important to continue three areas of research that have been going on at OSU.

  1. Detection: If the compounds are not present, then there’s less to worry about.

    Good times with lab mates when Steven O’Connell (right) first started working in the Anderson lab.
  2. Toxicity:  Addresses concerns over compounds that are detected in environmental samples.
  3. Processes by which OPAHs are made or degraded.

With that knowledge, it will become easier to understand potential risks with this compound class.

Why is this paper important in advancing the science?

My paper is very analytical.  If you watch the television series Bones, I would be most like Hodgins, except there would be less talk of “particulates” and more talk of cleaning instrumentation.  But seriously, by providing two methods on very different instrumentation to measure over 20 OPAHs, I provided a helpful platform for other scientists to use and build upon to measure this compound class in a variety of applications.

We are excited to be hosting the ISPAC 2013 Conference on September 8-12, 2013, on the beautiful campus of Oregon State University (OSU) in Corvallis.

ISPAC 2013 will focus on the research of Polycyclic Aromatic Compounds (PACs) on multiple fronts of analytical measurements, toxicology, organic synthesis, human exposure and health effects, and environmental presences, sources, fate and transport. It is a forum that brings together researchers worldwide to communicate, learn and advance the field of PAC. In addition, we intend to have an exhibition involving chemical products, analytical instrumentations and services involving PACs.

Engage on Social Media!

We will be tweeting highlights during the conference at  #ISPAC13. Be sure to use the hashtag when sharing! If you are unable to attend, we hope you will stay connected and engage on Twitter.

The Community Engagement Core (CEC) engaged 27 Tribal members in three 90-minute focus group sessions to elicit feedback about tribal indicators of health, environmental health concerns, and the importance of smoked food as a cultural tradition. The findings were published in Environmental Justice.

Schure M, Kile ML, Harding AK, Harper B, Harris S, Uesugi S, Goins T. Perceptions of environment and health among community members of the Confederated Tribes of the Umatilla Indian Reservation.  Environmental Justice. June 2013, 6(3): 115-120. doi:10.1089/env.2013.0022.

The CEC was also featured  in the NIEHS publication, Celebrating 25 Years of the Superfund Research Program for research on PAH exposures during traditional smoking of salmon with the CTUIR research. You can also view the Please view the 2011 report for more information.

 

Stuart Harris and Anna Harding in a tipi smoking salmon
Mr. Stuart Harris and Dr. Anna Harding sit in the tipi that is measuring the air quality when smoking salmon.

As part of our focus on PAHs, we sampled the polycyclic aromatic hydrocarbons (PAHs) in air and water in the Gulf of Mexico related to the oil spill. The level of PAHs in crude oil varies between 0.2 and 7%, depending on location. Although this seems like a small percent, PAHs are a significant toxicological health concern.

Sampling was accomplished by the research staff of Project 4 using passive sampling devices (PSDs).

The Community Engagement Core (CEC) collaborated with the EHSC COEC to create PAH-related environmental health education that applies to the Gulf of Mexico Oil Spill research of Project 4.

See the Gulf of Mexico Spill Main Page for videos, resources, and more details about the research using passive sampling devices.
OSU Deepwater Horizon Spill Research
Initial research crew in 2010 after the Deepwater Horizon Oil Spill.
Pictured left to right: Kevin Hobbie, Dr. Kim Anderson,
Sarah Allan, Lane Tidwell