January 7, 2014
Newly Discovered Carcinogens Hundreds Of Times More Dangerous
April Flowers for redOrbit.com - Your Universe Online
New compounds produced by certain types of chemical reactions, such as those found in vehicle exhaust or grilling meat have been found by a research team at Oregon State University. Their findings, published in Environmental Science and Technology, reveal that these compounds are hundreds of times more mutagenic than their parent compounds, known as carcinogens.
The previously unknown compounds raise concerns about the health impacts of heavily-polluted urban air and dietary exposure. The researchers have not determined in what level the compounds might be present, and because they were previously unknown, no health standards exist for them.
The team used laboratory experiments designed to mimic the type of conditions that 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.
Polycyclic aromatic hydrocarbons (PAHs) are the parent compounds that are formed naturally as the result of almost all types of combustion, from a wood stove to an automobile engine, cigarette or a coal-fired power plant. A variety of PAHs are carcinogenic, like benzopyrene. These carcinogens are believed to be more of a health concern than previously thought, and are the subject of extensive research at OSU and other research institutions around the world.
The research team says that the PAHs become even more of a problem when they chemically interact with nitrogen. These 'nitrated' compounds, known as NPAHs, were previously unknown as well.
The findings show that the direct mutagenicity, the ability of a chemical to cause mutations, of the NPAHs with one nitrogen group can increase 6 to 432 times more than the parent compound, while those with two nitrogen groups can be 272 to 467 times more mutagenic. DNA damage in cells that can later lead to cancer is caused, in part, by these chemical mutagens.
The researchers believe these numbers might even understate the real increase in toxicity.
Simonich based this research on earlier PAH studies done by her team at the Beijing Summer Olympic Games in 2008. The team performed extensive studies of urban air quality, based largely on concerns about the health impacts on athletes and visitors to the games.
Like other major Asian cities, Beijing has significant problems with air quality. At times, it may be 10 to 50 times more polluted that the average major urban areas of the US, such as Los Angeles.
Last fall, the World Health Organization (WHO) announced that it now considers outdoor air pollution, especially particulate matter, to be carcinogenic, and to cause other health problems as well. PAHs are one type of pollutant found on particulate matter in air pollution, and they are of special concern.
Simonich is also monitoring Oregon’s Mount Bachelor, a 9,065-foot mountain in the central Oregon Cascade Range. Scientists want to determine the level of air pollution that might be found there after traveling thousands of miles across the Pacific Ocean.