Science Tuesday - Airport scanners, surviving shipwrecks, rabies, and the Iron Age

X-Ray Scans at Airports Leave Lingering Worries
By RONI CARYN RABIN, The New York Times, AUGUST 6, 2012

Even before she was pregnant, Yolanda Marin-Czachor tried to avoid the full-body X-ray scanners that security officers use to screen airport passengers. Now she's adamant about it: She'll take a radiation-free pat-down instead any day.

"I had two miscarriages before this pregnancy," Ms. Marin-Czachor, a 34-year-old mother and teacher from Green Bay, Wis., recalled, "and one of the first things my doctor said was: 'Do not go through one of those machines. There have not been any long-term studies. I would prefer you stay away from it.' "

There are 244 full-body "backscatter" X-ray scanners in use at 36 airports in the United States. They operate almost nonstop, according to the Transportation Security Administration. Other airports use millimeter wave scanners, which look like glass telephone booths and do not use radiation, or metal detectors.

Most experts agree that as long as the X-ray backscatter machines are functioning properly, they expose passengers to only extremely low doses of ionizing radiation.

But some experts are less sanguine, and questions persist about the safety of using X-ray machines on such a large scale. A recent study reported that radiation from the machines can reach organs through the skin. In another report, researchers estimated that one billion X-ray backscatter scans per year would lead to perhaps 100 radiation-induced cancers in the future. The European Union has banned body scanners that use radiation; it is against the law in several European countries to X-ray people without a medical reason.

( Read more... )

In Crises at Sea, Chivalry Dies First
By NICHOLAS BAKALAR, The New York Times, August 6, 2012

As the Titanic began to sink in the early hours of April 15, 1912, the captain ordered women and children first to the lifeboats. Ultimately, he went down with the ship.

The order has long been held up as an example of modern chivalry, an unwritten law of the sea. But a new review of historical records suggests that in maritime disasters, “every man for himself” is a rule more commonly applied, and that women and children die at significantly higher rates than male passengers and crew members.

Two researchers at Uppsala University in Sweden examined records of 18 ship accidents from 1852 until 2011, which involved more than 15,000 passengers and crew members. They selected accidents for which there is complete data on survivors and decedents by number and sex, and they limited their sample to wrecks involving 100 people or more in which at least 5 percent died or 5 percent lived.

Their findings suggest that the events on the Titanic, where 20 percent of men and 70 percent of women and children lived to tell the tale, were highly unusual, if not unique.

( Read more... )

Peru: Antibodies Seen in Amazon Dwellers Suggest That Rabies May Be Survivable
By DONALD G. McNEIL Jr., The New York Times, August 6, 2012

Defying conventional wisdom about rabies, a new study suggests that the disease may not be 100 percent fatal.

Scientists who took blood samples from 63 relatively healthy villagers in the Amazon jungle in Peru, where vampire bat bites are common, found seven people who had antibodies to rabies. Only one reported ever having had a rabies shot (which would also produce antibodies).

The study, led by scientists from the Centers for Disease Control and Protection and Peru’s Health Ministry, was published Aug. 1 in The American Journal of Tropical Medicine and Hygiene.

Rabies kills about 55,000 people a year, mostly in Africa and Asia; many are children bitten by dogs. But in Peru, 81 percent of known rabies deaths are from bats.

More than half the Amazon villagers interviewed said they had been bitten; vampire bats can drink without awakening their victims.

( Read more... )

Iron Age Creativity in a Turkish King’s Image
By SINDYA N. BHANOO, The New York Times, August 6, 2012

Archaeologists have discovered a giant statue of a Turkish king that dates back 3,000 years.

The partly broken sculpture of the king’s head and torso stands nearly five feet tall, and the full sculpture may have been more than 10 feet, said Timothy P. Harrison, an archaeologist from the University of Toronto who was part of the team that made the discovery.

The piece demonstrates that creativity and intellect flourished in the Iron Age, though cities and kingdoms were small and independent — unlike the centralized system of the earlier Bronze Age. “This counters our intuition that big empires are what produced creativity,” Dr. Harrison said.

( Read more... )