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"Clearly, this is an opportunity to get rid of something to say they did something. There's no scientific, valid reason for these bans to pass. They do no environmental good, and they do economic harm."
LeHuray points to dozens of other sources of PAHs in the environment, and their widespread finding of the compounds across the globe as evidence.
"The thing about PAHs in general – they are the single most studied suite of chemicals in the environment, and they are found absolutely everywhere. They have been found in remote alpine lakes and in the Arctic. They are ubiquitous," she said. "They are found in your food supply – by grilling meat, vegetables and fish, but also in coffee and tea and hot chocolate. They are in anything you heat up. If you roast coffee, you're making PAHs."
There are, indeed, hundreds, if not thousands, of sources of PAHs in the environment and in our homes. In short, PAHs are compounds made from a mix of carbon and hydrogen formed most often by the incomplete burning of animals or plant matter, coal or petroleum and other organic materials. Cigarette smoke is one of the main contributors of PAHs in an indoor environment, but panfrying food and fireplaces also produce PAHs. That black soot that builds up in chimneys is chock-full of carcinogenic PAH compounds. Outside, they are produced by BBQ grills, fires, car exhaust, asphalt pavements, asphalt sealcoat and many other sources. They are even found in mothballs, some special-purpose skin creams, and some anti-dandruff shampoos. They exist in the air by clinging to tiny particulate matter, in aquatic sediments and soil.
Of all the PAHs that exist, the United States Environmental Protection Agency (EPA) has classified seven as probable human carcinogens, and 16 as priority pollutants. The environmental and human effects of PAHs depend on which are present and their concentrations.
While LeHuray doesn't dispute that coal tar-based sealcoat contains PAHs, she said she doesn't believe that sealcoat is a major source of PAH contamination in homes or the environment. Instead, she said, she believes studies by the USGS and others that are blaming sealcoat as a source of contamination are simply looking for a way to justify their jobs.
"There is a phrase called 'emerging contaminants of concern,'" she said. "That typically means we are looking for other contaminants to keep our funding stream going."
The Great Lakes Restoration Initiative, a federally-funded effort focusing mostly on stopping invasive species, improving wetlands and removing outdated dams, also supports research into issues of emerging concern. In March, the USGS released a study about contaminants in Great Lakes tributaries, which included the Clinton and Rouge rivers....continued on page 4