polycyclic aromatic hydrocarbons

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New studies: Toxic asphalt sealants threaten kids, cause air pollution

When you think of pollution, you might picture an industrial center like Camden, N.J., or Jersey City. But new research shows that when it comes to a potent class of cancer-causing toxic chemicals, many American parking lots are a lot worse.

New studies paint an increasingly alarming picture – particularly for young children – about how these chemicals are being spread across big swaths of American cities and suburbs by what may seem an unlikely source – a type of asphalt sealer. These sealants are derived from an industrial waste, coal tar.

Four new studies announced this week further implicate coal tar-based asphalt sealants as likely health risks.  The creosote-like material typically is sprayed onto parking lots and driveways in an effort to preserve the asphalt. It also gives the pavement a dark black coloring that many people find attractive.

Coal tar is a byproduct of the steelmaking industry. In 1992, the U.S. Environmental Protection Agency declared that it would not be classified as a hazardous waste, even though it met the characteristics of one, because it could be recycled for uses including coating asphalt. That meant steel mills didn’t have to pay for costly landfilling or incineration of the waste.

 Only in recent years have scientists discovered the ill effects of this practice.

Coal tar sealants are used most heavily in the eastern United States, but have been used in all 50 states until Washington State banned the products last year as a result of reporting by InvestigateWest. More than a dozen local governments, including Washington, D.C., and Austin, Texas, also have banned the coal tar sealants in favor of the other major type of sealant, which is asphalt-based.


WA Legislature: Let's become first state to ban toxic asphalt sealants

The Washington House of Representatives this week passed and sent to Gov. Christine Gregoire legislation to make Washington the first state in the nation to ban toxic asphalt sealants that are ending up in people’s homes as well as polluting stormwater runoff and waterways.

Meanwhile, a federal scientist on Thursday briefed Congressional aides and others about threats to the environment and public health from sealing of driveways, parking lots and playgrounds with coaltar, a byproduct of steelmaking. The briefing was co-sponsored by U.S. Rep. Lloyd Doggett, D-Texas, who is seeking a nationwide ban on the toxic sealants.

The Washington State legislation and Doggett’s drive for a nationwide ban flowed from studies by the U.S. Geological Survey, which showed that constituents of the toxic sealants are increasing in many waterways, while levels of most pollutants are declining.

A 2009 Geological Survey study identified chemicals associated with the coaltar sealants in house dust at levels that worried researchers because they could contribute to longterm cancer risks, especially in young children who crawl around in – and accidentally ingest – the toxic dust.

InvestigateWest and msnbc.com partnered last year to publish the first major national story examining the toxic sealants.


Study sees parking lots dust as cancer risk


Chemicals in a cancer-causing substance used to seal pavement, parking lots and driveways across the U.S. are showing up at alarming levels in dust in American homes, prompting concerns about the potential health effects of long-term exposure, a new study shows.

The substance is coal tar sealant, a waste product of steel manufacturing that is used to protect pavement and asphalt against cracking and water damage, and to impart a nice dark sheen. It is applied most heavily east of the Rockies but is used in all 50 states.

Toxic parking lots shed dust that boosts kids' cancer risk, InvestigateWest says in major story

rm iwest mugOK, folks, it's the moment we've all been waiting for since we launched InvestigateWest last year: Our first big story is running today! And it's on msnbc.com, so we expect a lot of eyeballs to be on this 0ne.

This is an amazing tale about a series of studies that this week revealed that toxic dust from parking lots is making its way into Americans' homes in eyebrow-raising quantities. And because it's ending up in house dust, it's a particular worry for kids, for whom it raises lifetime cancer risks significantly, according to research led by the U.S. Geological Survey.

Please go read the story, will you? We want to get all the clicks we can over at msnbc.com. But do come back and visit Dateline Earth in the next week or so, because there was really quite a bit we didn't get to get into, even in the decently in-depth treatment we were able to give the topic for msnbc.com.

InvestigateWest has been proud of what we've been able to accomplish so far, including our independent coverage of the Copenhagen climate talks, organizing into a non-profit, getting an incredibly talented board up and running, and landing grants from the Bullitt Foundation and the Fund for Investigative Journalism.

But this toxic parking lots piece is a great example of our main reason for being: In-depth journalism on the environment, public health and social-justice issues (although this coal tar thing, in an unusual twist, seems likely to be more of a problem for well-to-do suburban families than for poor folks.

Air pollution makes our kids dumber and sicker

Two recent studies suggest that air pollution at levels common in urban areas causes children to have higher rates of a potentially fatal lung infection and reduces the IQ levels of the kids exposed most heavily in the womb.

All this happens at air-pollution levels common in urban areas. 

The finding about the dumber kids exposed in the womb comes out of the Columbia Center for Children’s Environ­mental Health in New York City, where scientists equipped expectant mothers to wear air-pollution monitors as they went about their daily routine.

One finding, outlined in Scientific American this week and much earlier on a site called babycenter.com: Pregnant women who experienced the highest exposures to pollutants known as polycyclic aromatic hydrocarbons had children with IQ scores four points lower on average than kids born to less-exposed mothers. SciAm's Sunny Sea Gold's story says there's more from another study:

Children’s growing brains are not the only ones affected by this dirty air. A 2008 study in 20- to 50-year-olds conducted jointly by the schools of public health at Harvard University and the University of North Carolina at Chapel Hill pinpointed ozone-related reductions in attention, short-term memory and reaction times equivalent to up to 3.5 to five years of age-related decline.

Meanwhile, here in Rain City, MSNBC and Discovery News bring us the tale of  University of Washington researcher Catherine Karr, who just released a study stating that ongoing exposures to air pollution increases a baby's chances of coming down with a lung infection called bronchiolitis.

Pollution from cars makes our kids dumber

In-womb exposure to components of air pollution can depress childrens' IQ scores about as much as exposure to lead, new research shows.

In fact, it might cause as much of a diminution of intelligence as fetal alcohol syndrome, according to a Science News story by Janet Raloff.  The research by Columbia University's Frederica Perera traced exposure of expectant mothers in New York City's Harlem, South Bronx and Washington Heights neighborhoods to components of auto exhaust known as polycyclic aromatic hydrocarbonsscience-news-cover-august-07. (I can say that five times fast -- can you?)

The exposed children showed an average IQ drop of 4.3 points. While that doesn't sound like much unless it's your own child, Bruce Lanphear of Simon Fraser University, just up the road in Vancouver, B.C., told Raloff that if one extrapolates that across the whole United States:

A downward shift in IQ by 5 points will increase by 3.5 million the number of children who meet the criteria for mental retardation.

It's a pretty clear case of a situation where controlling the pollution would be cheaper for society in the long run, Raloff writes.

Perera's paper was one of several discussed this week at a National Academies of Science workshop that also touched on how car-based pollutants can spark athsma, and how contaminants can turn genes on and off even if they don't outright damage DNA.

The workshop, covered in a wide-ranging story by Bette Hileman in Environmental Health News, delved into whether pollutants might be doing damage by turning off genes, or turning them on at the wrong time in an organism's development.