Janice Horowitz: Dueling Docs: Are airport body scanners safe?
Last Updated on Sunday, 28 February 2010 11:15 Written by Daisy Harley Sunday, 28 February 2010 11:15
The Issue
Body scans at the airport
The facts
Usually there’s a medical reason for getting an x-ray. But now, to ensure that air travelers aren’t packing explosives, the U.S. government is gearing up to require body scans on anyone who flies. The Transportation Security Administration (TSA) already has 40 scanners in 19 airports nationwide. In six of those airports, the machine is used for primary screening; at the others they’re used for follow-up searches if there’s a suspicion of wrong-doing.
Scanners, dubbed by some as “virtual strip searches,” have been used on products, not people, entering the U.S ports for years. But for today’s traveling public, there are two types of approved scanners. One uses radio-wave technology, which employs radio waves tens of thousands of times lower than those in cell phone technology–and which experts agree are largely benign. The other scanners use x-rays. They may allow for better images, but they’ve also created the most stir over any health effects on frequent flyers.
The government is convinced the x-rays scanners are good for the security of the flying public, but are they okay for you?
Two experts debate the issue: Dr. Mahadevappa Mahesh, chief physicist and radiology professor at Johns Hopkins University Medical School and Arjun Makhijani, nuclear engineer and president of the Institute of Energy and Environmental Research in Maryland.
The Debate
Dr. Mahesh:
“The medical risk of airport body scanners is negligible,” says Mahesh. “I don’t have any vested interest in defending these scanners. I’m trying to discuss the science. The radiation used in these machines is low-intensity and doesn’t even transmit through the body; it reflects off the skin. The scanners go through clothes only. They can catch explosive taped to the body or hidden under clothes. They don’t see into the body.”
Mahesh explains that the dose of radiation of each scan is .05 to .1 micro-sieverts. (micro-sieverts is a measure of radiation dose). “A chest x-ray is equivalent to 100 micro-sieverts. That means a person would have to have 1000 to 2000 airport scans to add up to the radiation he would get from just one chest xray.”
Moreover, says Mahesh, the radiation must be viewed in context. “Just flying in a plane exposes people to radiation. The average radiation exposure at 100,000 ft in the air is 4 micro-sieverts an hour, many times more than the radiation from a scanner. And the general population, including people who don’t fly, are exposed to background radiation of about 3,100 micro-sieverts every year.”
Can the scanner’s operator make a mistake that would harm the passenger? “No,” says, Mahesh. “There are no settings for the operators to confuse. It’s push-button technology. Whether the traveler is a small child or an obese patient, the machine’s settings don’t have to be changed. Truth is, for those people who are totally paranoid about radiation, there’s no convincing them that scanners are ok.
“But,” says Mahesh. “It’s highly important that these machines are tested yearly by a qualified person not associated with the manufacturer to make sure they are operating properly.
“There are privacy concerns, to be sure. The machine can distinguish between natural tissue and silicone. So if someone’s had a breast implant, it will show up. But there is nothing like a perfect security system.”
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Arjun Makhijani:
“I’m not saying scanners should not be used, I’m saying there should be a public process,” says Makhijani. “The use of scanners needs to be debated before you impose even a de minimis risk on the public. We have about 600 million air passengers every year. On average each person takes two flights. In order for scanners to be effective, the effort would have to be global. We’re talking about a couple of billion scans a year–that’s a lot of scans. And it’s nonsense to say that the radiation of these scanners don’t absorb through the body.
“By the conventional methods of calculation, once you expose billions of people to these very low doses of radiation, you will induce some cancers, and a few cancer deaths every year. They may be non-detectible, but they will be there.”
Makhijani goes on: “We really need to look at what benefit we’re getting from these scanners. Certain kinds of plastic explosives will remain undetectable. People can also swallow an explosive or hide them in body cavity like the anus or vagina and that won’t be detectable.”
Makhijani worries that use of scanners would actually introduce new risks. “Who will look at these pictures? It may be possible that the job will attract a small minority of people who could be child abusers, for example. They will be able to figure out how to store these images.
“What’s more, in many societies, particularly in parts of the Islamic world, modest clothing for women is very important and yet, with these scanners, a silhouette of the body can be seen. We will be forcing people from Islamic countries to go through these machines. We are putting this on a society that is already antagonistic to the US.
“We must ask ourselves as part of a debate. ‘How would the Muslim world perceive such a thing?’ We have to look at whether scanners could actually increase terrorist risk because of the extreme anger that they might induce. We simply have not debated any of this. And we must.
“If you’re close to the needle in the haystack, do you want to increase the size of the haystack or figure out how to grab that needle? We are putting into place machinery that increases the haystack. I’m not saying they should never be deployed. All I’m saying is that the decision to spend the money to buy and operate these machines in a hasty fashion, without consideration of any potential increase of terrorism risk or collateral risks, such as child pornography, for example, is not the way to go. We need to open this up to public debate.”
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Article source: http://www.huffingtonpost.com/janice-horowitz/dueling-docs-are-airport_b_480187.html
Learn MoreJanice Horowitz: Dueling Docs: Can you take a drug for jet lag?
Last Updated on Monday, 22 February 2010 01:45 Written by Daisy Harley Monday, 22 February 2010 01:45
The Issue
Drugs for Jet Lag
The facts
With all the stress of travel these days – the requisite shoe-removal, luggage surcharges and now the possibility of body scans – there may soon be relief for one travel headache that’s been about as immutable as traffic on the way to the airport. Jet lag. The U.S. pharmaceutical company, Cephalon, is currently awaiting FDA approval for Nuvigil, a drug that promises to combat the sleepiness associated with jet lag.
If it gets the nod, Cephalon will market Nuvigil to business travelers who plan to stay abroad for just a couple of days. That’s because Nuvigil is not actually meant to set travelers’ internal “circadian” clock to a distant time zone, but rather to keep them awake enough to get through a business meeting when they arrive at their destination. The idea of stay-awake drugs is not new. In fact, Nuvigil is a chemical cousin to Cephalon’s hugely successful Provigil, the stimulant drug that college kids cramming for exams and soldiers in the field have been downing for years. Nuvigil works almost precisely the same way as Provigil does and since June has been available to treat disorders like sleep apnea and narcolepsy. But only Nuvigil could be become the first-ever drug approved for jet lag.
Should you take Nuvigil or any stay-awake drug to cope with overseas travel?
Two experts debate the issue: Richard Bogan, MD, the lead investigator for the Nuvigil clinical trial and Leon Kreitzman co-author of Rhythms of Life: The Biological Clocks that Control the Daily Lives of Every Living Thing
The Debate
Dr. Richard Bogan:
“As a clinician, if a patient comes to me and says ‘I’m going to Paris, I feel sleepy when I get over there and need to function well – do you have something for me?’ I’d say, yes, if Nuvigil is approved. The science is there for us to prescribe something. There are a number of behavioral strategies to change your circadian clock to combat jet lag, but they take a number of days. Instead, we have a compound that will improve the wakefulness of people who need to function normally when they arrive in a foreign country.”
“In our study, the majority of patients who took Nuvigil had significant improvement in their wakefulness measured subjectively or objectivity and the side effects were mostly mild,” says Bogan.
Why not just take Provigil, which already available has a proven track-record for keeping people awake? “I suspect that Provigil will work and there is nothing to prevent people from taking Provigil for the sleepiness associated jet lag,” says Bogan, “but it’s not approved by the FDA for that.”
Bogan adds that Nuvigil would work better anyway because it lasts longer. “Nuvigil has a longer half-life than Provigil, meaning it takes longer to wear off and you stay awake longer. The idea is for travelers to keep awake for 15 hours once they arrive at their destination and then sleep for eight hours that night.” Says Bogan: “The drug doesn’t affect your ability to get to sleep when you want to and stay asleep.”
Bogan says that researchers don’t know exactly how Nuvigil works. “We know Nuvigil is not an amphetamine. And based on the science it wouldn’t prevent you from going to sleep at night when you want to. And from a theoretical perspective, it shouldn’t interfere with your body’s ability to adjust its circadian clock if you want to adjust.”
What about side-effects? “Most people in the study experience no or mild side effects,” says Bogan. However, he says, “some patients can’t take the drug. They experienced headache, dizziness, nauseous and a very low number experienced vomiting.”
Leon Kreitzman:
“Jet lag and sleepiness after travel are not life-threatening. You might miss a night of sleep or two nights sleep, but this is not a medical, much less life-threatening condition. I suspect that what’s underlying the company’s push for a new drug is not that they are offering a genuinely therapeutic agent. It’s a marketing decision. The patent for its Provigil is coming up in a few years. The drug maker is looking for a variant of Provigil to keep its hold on market share. And in the process, they are using a drug to provide something that’s really just about lifestyle.”
“There are indeed great things about Nuvigil and Provigil. Typically, they can keep you awake without obvious short-term side-effects. But the truth is we don’t know about the long-term side effects of these drugs. The company is marketing Nuvigil for business travelers who go someplace for just a day or two and may need the drug occasionally, but what if these folks take it every time they travel, time and again. The problem is that for ethical reasons nobody can do a long-term study to find out.
“Jet lag is due to a disruption in one’s 24 hour circadian rhythm. The rhythm adapts to whatever local condition you’re in. If you go to another part of the world, say, a place that’s10 hours ahead of you, it’ll take one hour per day or 10 days to adjust. But when you first arrive, your body’s physiological functions are out of whack. For some, jet lag affects sleep patterns, so they feel fatigued. For others, decision-making may be impaired and others will experience bowel irregularity.”
“The problem is that there isn’t one circadian clock in the body. There are many rhythmic clocks, each for different functions. The liver may be timed to the schedule of food intake, while the brain takes different cues. Then like an orchestra, there is also a master clock which tries to keep all the different clocks together. But when you go on a long trip, that master synchronization breaks down and instead of getting a nice tune you get cacophony. Nuvigil, as far as we know, does nothing to address the rhythms of our body. It will do nothing to quell the cacophony that results from traveling through time zones. But it will keep you awake without feeling fatigued.”
“In my opinion, most people can handle the sleepiness associated with jet lag for one or two days. Even so, you could do things without drugs to make the transition to another time zone easier. There’s not much point in trying to completely switch over your circadian rhythm if you’re gone for just a couple of days, because you’ll be right back home again. Still, trying to shift your body slightly might make you feel better.”
“What can you do? Try to prepare your body before you go. You might go to bed a different time a couple days before you travel. Try to moderate the timing of your meals, too, to match your destination meal time. Don’t drink alcohol on the plane; it seems to have a reinforcing effect on jet lag. Instead, drink plenty of water. Eat moderately – try to have fresh food because your body has less capability of digesting fatty food at night. And if you’re arriving in the morning, then do look at sunlight to tell your body it’s morning.”
“Actually, the more sensible thing is to go a day earlier and start switching over your clock to local time. Of course, if your internal clock shifts to the new time, that might be harder for you when you come back. You’ll probably come home and crash a bit.”
More on Sleep
Article source: http://www.huffingtonpost.com/janice-horowitz/dueling-docs-can-you-take_b_471732.html
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