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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.
The machines move a narrowly focused beam of high-intensity radiation very quickly across the body, and David Brenner, director of the Center for Radiological Research at Columbia University Medical Center, says he worries about mechanical malfunctions that could cause the beam to stop in one place for even a few seconds, resulting in greater radiation exposure.
For security reasons, much about how the machines work has been kept secret. The T.S.A. says the full-body scanners have been assessed by the Food and Drug Administration, the United States Army Public Health Command and the Johns Hopkins University Applied Physics Laboratory.
But researchers at these institutions have not always had direct access to the scanners in use, and some of the published reports about them have been heavily redacted, with the authors' names removed. Independent scientists say limited access has hampered their ability to evaluate the systems.
John Sedat, emeritus professor of biochemistry and biophysics at the University of California, San Francisco, believes that the effective dose could be 45 times as high as the T.S.A. has estimated, equivalent to about 10 percent of a single chest X-ray.
T.S.A. officials scoff at scientists' statements that measuring the effective radiation dose received by passengers is very complex, saying that it is not difficult, that the machines are inspected for problems at least once a year, and that they are equipped with fail-safe shutoff systems.
The machines, though, have had mechanical problems. A recent T.S.A. report said that between May 2010 and May 2011, there were 3,778 service calls concerning mechanical problems in backscatter X-ray machines. Radiation safety surveys were conducted after only 2 percent of the calls.
In a letter to the federal Department of Health and Human Services dated Oct. 12, 2010, the scientists said that "the casual nature for maintenance of these devices is alarming to us. These machines are capable of delivering large X-ray doses.
They added, "Hospitals usually check for problems on X-ray machines daily."
Most of what is known of the risks of radiation has been extrapolated from disease trends in Japan after World War II.
T.S.A. officials say that these low doses of radiation are safe for everyone, including pregnant women, infants and young children, even though children are significantly more sensitive to radiation's effects.
Those at greatest risk, however, may be T.S.A. employees and others who work in the terminals and go through security daily. A 2004 National Institute for Occupational Safety and Health study of T.S.A. baggage screeners urged the agency to have employees wear film badges to monitor ongoing exposure systemically, as many hospital and lab employees do, and to label machines more prominently. The agency has not done so.
While the risk to the average passenger may be low, here are some suggestions for those who wish to reduce their exposure.
- Get to the airport early. That gives you extra time to opt for a pat-down if you want.
- If you are pregnant or think you may be pregnant, tell a T.S.A. agent. You may be allowed to pass through a metal detector without additional screening.
- The younger children are, the more sensitive to radiation. T.S.A. employees have been known not to require children under 13 to go through an X-ray machine, although the agency denies there is any policy on this.
- If you have any concerns about medical conditions, you have the right to opt for a pat-down by a T.S.A. employee.
Readers may submit comments or questions for The Consumer by e-mail to consumer@nytimes.com.
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.
The Titanic and the Lusitania, a passenger ship torpedoed by a German submarine on May 7, 1915, accounted for more than a quarter of all casualties in the study. So the researchers made calculations with and without those two ships to avoid statistical bias. Among almost 2,000 passengers and crew members on the Lusitania, there was little difference between men’s and women’s survival rates — 37.1 percent for women and 40 percent for men.
Of the other 16 wrecks examined, women survived at a higher rate than men in only one: the grounding of the British ship Birkenhead off Cape Town in 1852.
In five of the disasters, there was no discernible difference in survival rates between men and women. In 10 of them, men survived at significantly higher rates. Over all, women did about half as well as men: 17.9 percent of them survived, compared with 34.6 percent of men.
Crew members of ships in trouble were apparently quite helpful — to themselves. Compared with passengers, they were 18.7 percent more likely to survive, the researchers found. Children fared worst: Of 621 on the ships, only 95, or 15.3 percent, lived on.
The study, published last week in Proceedings of the National Academy of Sciences, also calls into question the value, even the existence, of an unwritten law of the sea by which the captain invariably orders “women and children first.”
In 2 of the 18 cases, accidents in 2008 and 2011 resulting from poor weather, no one knows if the captain gave such an order. But in 11 of the remaining 16 sinkings, no such order was issued. Where the order was given, it seemed to be somewhat helpful — the survival rate of women on those ships was 9.6 percent higher than the overall survival rate of women on the ships in the analysis.
Still, the finding suggests that when men do allow women to go first, it may be less an act of chivalry than a response to a command from a person in a position of authority.
Some have suggested that chivalry at sea is a defining characteristic of the British, and that behavior on British ships is guided by this tradition. But even counting the Titanic and the Lusitania, the survival rate for women on the eight British ships in the study was significantly lower than on ships flying other flags, and women died more often than men whether or not the “women and children first” order was given.
“The study suggests there isn’t a particular British tradition of women and children first,” said Lucy Delap, a lecturer in British history at Cambridge, who was not involved in the study. “No, actually women are less likely to survive on British ships, apart from the Titanic.”
The Titanic, she added, “has become a mythic presence in shipwrecks.”
“Although people say it illustrates the unwritten rule of the sea, it really isn’t illustrating a rule at all,” Dr. Delap said. “For a British commentator, that makes for slightly uncomfortable reading.”
Despite the findings, an author of the study, Oscar Erixson, a doctoral student at Uppsala, was not prepared to condemn the behavior of men, British or otherwise.
“You could argue that men acted badly, but it’s hard to say how the women acted,” he said. “We haven’t studied individual behavior. Women could have acted just as badly but didn’t succeed against stronger competition.”
It may be, Mr. Erixson continued, that it is not men’s or women’s behavior that is at issue, but human behavior. “Survivors may feel bad if we accuse them of acting selfishly,” he said, “but wanting to take care of oneself rather than others — this may be normal behavior for all human beings.”
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.
Several Americans have survived rabies without getting post-exposure shots, but almost always after intensive care, including induced comas. A rare exception is believed to be a Texas teenager in 2009 whose rabies was diagnosed only after she had been treated for what was thought to be bacterial or viral encephalitis. She was never in intensive care and yet survived.
It is not known what factors might make some people naturally resistant to rabies. But if some people are, an editorial with the study said, sequencing their genomes may lead to a cure.
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.
The archaeologists are digging in what was once a neo-Hittite city. The sculptures are from the inside of a gate complex that provided access to the upper citadel of Kunulua, the capital of a small kingdom called Patina between 1000 B.C. and 738 B.C.
The sculpture, which is intricately detailed, is of a king named Suppiluliuma who reigned in the ninth century B.C. On the back of the statue, Dr. Harrison said, is an autobiographical statement written in the Hieroglyphic Luwian language.
In the inscription, the king discusses how he successfully expanded the borders of his kingdom and erected a monument honoring his father.
Dr. Harrison said the statue was probably damaged and buried during an Assyrian invasion of Suppiluliuma’s kingdom in 858 B.C. He says he hopes that over time, the full statue can be restored.
