Monday, November 5, 2007

Drive Time Raises Health Risk

You eat carefully, do not smoke, exercise regularly and think you are taking good care of yourself. But if you drive to work in a heavily congested area such as Los Angeles or Washington, the traffic may be undermining your efforts. A new study has found that while Los Angeles residents spend about 6 percent (1.5 hours) of their day on the road, drive time accounts for between 33 and 45 percent of their exposure to harmful air pollutants.

The two most common pollutants are diesel exhaust from trucks and ultrafine particles produced when car engines begin to accelerate. Both have significant detrimental health effects.

"If you have otherwise healthy habits and don't smoke, driving to work is probably the most unhealthy part of your day," said Scott Fruin of the University of Southern California.

Ultrafine particles are of particular concern, he said, because they can penetrate cell walls and spread throughout the body. Chemical particles in the air have been linked to cardiovascular disease, and the ultrafine appear to be the most toxic.

Researchers measured the roadway air pollution for three months in 2003 by outfitting an electric vehicle with instruments that collected data on the air contents, and videotaped the surrounding traffic and driving conditions on freeways and roads.

The study was done by researchers at USC and the California Air Resources Board and published this month in the journal Atmospheric Environment. The Washington area has some of the worst traffic and longest drive times in the nation.

-- Marc Kaufman

Rare Amphibian Imprints Found

Scientists from New Mexico and Pennsylvania have discovered unprecedented fossilized imprints of three amphibians in 330 million-year-old rocks in the Keystone State, which revealed the existence of previously unknown salamander-like creatures.

"Body impressions like this are wholly unheard of," said Spencer Lucas of the New Mexico Museum of Natural History and Science, who presented the findings at a meeting of the Geological Society of America in Denver last week.

David Fillmore, a senior at Kutztown University of Pennsylvania, discovered the imprints of the animals' webbed feet and bodies in reddish brown, sandstone rocks from the Mauch Chunk Formation in eastern Pennsylvania while researching his thesis. The rock specimen had been collected decades ago and stored in the Reading Public Museum, but no one had noticed the imprints.

Fillmore, along with Lucas and Kutztown State geology professor Edward Simpson, then examined the collection and found other imprints that suggest that larger four-footed creatures also existed at the time, far earlier than previously known.

The webbed feet confirm the animals were amphibians, and the imprints suggest that the foot-long animals had smooth skin rather than armored skin. Although scientists knew amphibians existed at the time, Lucas said in a phone interview, "we never had a body impression of these fossils."

-- Juliet Eilperin

Self-Righteous Prone to Extremes

When two researchers recently asked people whether they felt they were moral, and then asked whether they would ever cheat on a test, those who said they were the least likely to cheat turned out to be the same ones who had the strongest conviction that they were moral. No surprise there.

But when the researchers looked at the group who said they were the most likely to cheat, they found to their surprised that this group, too, had strong convictions that they were moral. Those who lacked a strong sense that they were moral tended to be iffy about whether they would cheat.

Scott Reynolds and Tara Ceranic of the University of Washington said their research highlights the idea that people with exceptionally strong convictions about their moral goodness are likely to follow extreme courses of action because they can convince themselves that whatever they do is good. When the right course of action is ambiguous, they added in a paper published in the November issue of the Journal of Applied Psychology, such people are likely to gravitate to opposite ends of a range of behaviors. When there is wide social consensus that something is wrong, they tend to conform to social norms.

When the researchers tested their hypothesis on managers who were asked to make a judgment call involving a conscientious employee who needed to go home early one day, they found that the managers who believed most strongly that they were good people came to extreme conclusions: They either let the employee off for the rest of the day with full pay, or insisted the employee stay and work full hours. The managers who did not think they were particularly good people tended to reach moderate conclusions: They had the employee finish some work and then leave early.

-- Shankar Vedantam

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