Holiday Hazards
Travel is fun -- that's why we do it. But it can also be, well, stressful. Almost all travelers have felt a creeping twinge of concern for their health and safety on the eve of a trip: Am I at risk of deep-vein thrombosis in economy class? Is my sunscreen up to the task? For the sake of my tummy, should I ask the bartender making those brightly colored beach-bar cocktails to hold the ice?
Then there's the delayed flights, dodgy-looking local dishes and language snafus that can send you exactly where you didn't want to be. And with new air routes opening up ever more far-flung destinations, and fears over diseases such as bird flu on the rise, the number of reasons to worry seems to be multiplying.
For frequent travelers, it makes sense to know what you need to fear -- and which worries you can leave at the gate. To help you take the right precautions without succumbing to a bout of travel-related paranoia, Weekend Journal consulted a crop of experts, from aviation researchers to microbiologists to hotel security specialists -- and even an authority on toilets. Our mission: to find out whether some common health and safety-related travel beliefs are myths -- or maxims.
Sitting in the back of a plane could save your life in a crash.
True -- if it were the type of crash in which sitting in the back of the plane could save your life. David Palmerton, cabin safety researcher with the U.S. Federal Aviation Administration, explains: "Accidents are so unique, and every accident has a different set of impacts." And it's those specific impacts that determine where the safest seats are -- for that particular incident. For example, the strongest part of a plane tends to be where the wings are attached to the fuselage. But the wings usually are also where the fuel is; fire could reach seats in that area first. While there have been several accidents where surviving passengers were sitting in the back of the plane, "I can give you just as many accidents where people in the front of the plane survived," Mr. Palmerton says. The best way to boost your chances of surviving a crash is to check for your nearest exits each time you fly.
Regardless of that, you may be lucky even if the worst does happen. One of the biggest plane crash myths of all is that if you are in one, your number is up. According to U.S. National Transportation Safety Board statistics, out of 719 accidents involving passenger and cargo flights of U.S. carriers between 1986 and 2005, only 72, or 10%, involved fatalities.
Economy-class passengers are at greater risk of getting deep-vein thrombosis.
Despite its popular nickname -- economy-class syndrome -- deep-vein thrombosis (the medical term for sometimes deadly blood clots that form in major arteries, usually the legs) doesn't have a confirmed spot on the cheap seats' long list of evils. A 2003 study published in the South African Medical Journal, "A Prospective Study to Determine Business Class Versus Economy-Class Syndrome as a Cause of Thrombosis," found no correlation between blood clotting levels and seat class. So far, no studies have concluded that passengers in the rear of the plane are at any greater risk of the condition, says Patrick Kesteven, chairman of the Scientific Executive Committee of a World Health Organization project that studies air travel and thrombosis risks. People flying first and business class have gotten deep-vein thrombosis, he points out: "Richard Nixon got DVT -- and I bet you he wasn't cramped." (The late former U.S. president frequently suffered from swollen veins when he traveled by air, and wrote in 1974 in his diary that he had been diagnosed with a blood clot on a trip to Hawaii.)
Researchers have confirmed that immobility can cause clots, and a new study published three weeks ago in the British medical journal The Lancet suggests that other factors, such as hypobaric hypoxia -- which means low oxygen levels in a low-pressure environment, such as an airline cabin -- could come into play. However, these factors aren't confirmed causes of clotting, says Suzanne Cannegieter, a physician at the Leiden University Medical Center in the Netherlands and one of the study's authors. As for seating, she says, it certainly makes theoretical sense that being folded up in economy would impede your circulation more than reclining on a flat bed in first class. But no studies have confirmed that is true. About 1% of DVT cases, by the way, are fatal.
The best advice: Move around regularly while in flight.
The air on a plane is full of germs.
Fears of virulent diseases such as bird flu and severe acute respiratory syndrome, or SARS, have brought this one to the fore, but is a plane really any more dangerous than an office, say, or an elevator? Half the air on a plane is outside air, and half is filtered and recirculated. So it would seem as though 50% of your onboard oxygen intake consists of other people's germy exhalations. But the recirculated half passes through high-efficiency particulate air filters, which typically catch almost all dangerous microbes, says K.Y. Yuen, head of the University of Hong Kong's microbiology department. And the cabin air gets filtered frequently. A well-maintained aircraft has about 20 air changes per hour; that airflow is roughly the same as that in a hospital operating theater, says Dr. Yuen, adding that a typical office building only has about five air changes per hour.
It isn't the air on a plane that is the problem, doctors say. "The risk is other passengers who might be close to you for long periods of time," says Dr. Yuen. A long-haul flight gives germs more of a chance to hop from one traveler to the next, as does the proximity of other passengers. Stuck near a sick person? If you can, Dr. Yuen advises, move to another seat.
To kick jet lag after a long-haul flight, sleep on the plane, adjust to the local time pronto, and don't nap when you land.
Mostly correct. Lim Li Ling, deputy director of the Sleep Disorders Unit at Singapore General Hospital, advises toughing out that first jet-lagged day without a nap, lest you fall into a long slumber. If you do take a nap, make it less than an hour, and do it in the morning or early afternoon, says Y.K. Wing, director of the Sleep Assessment Unit at the Chinese University of Hong Kong. Nap for longer -- or later -- than that, and it will just delay adjusting to your new time zone.
Set your watch to the new time zone as soon as you get on the plane, and where relevant, try to sleep and eat on that time zone schedule while you're still on the flight, says Dr. Lim. Sometimes, sleeping on board isn't the best solution; if you are scheduled for a late-evening arrival, she says, it might be better to stay awake in the air so you can hit the sack when you land.
You should also drink plenty of water, avoid caffeine and alcohol, and eat lightly on the plane, so your body isn't trying to digest a heavy meal at a time of day that it isn't accustomed to doing so. Dr. Lim says melatonin -- a hormone secreted by the body that helps regulate sleep cycles -- can also be taken as a supplement to help travelers adjust.
The higher the SPF, the better the sunscreen.
Theoretically yes, but people rarely use enough sunscreen to get the full benefit of the sun protection factor on a bottle's label, says Craig Sinclair, chairman of the National Skin Cancer Committee of Cancer Council Australia. SPF is technically a measure of how long you can stay in the sun until you burn, so, for instance, SPF 20 should provide burn protection twice as long as SPF 10. It does that in laboratory testing conditions, but is unlikely to in the real world, where sunscreen is usually less liberally applied than in a lab. In fact, a higher SPF does filter out slightly more ultraviolet B rays -- the main ones responsible for sunburn -- but the difference is small: 96.7% UVB blockage for SPF 30 versus 98% for SPF 50 under lab conditions, says Mr. Sinclair.
The real trick, says Colin Theng, a dermatologist with the National Skin Centre in Singapore, is reapplying every two hours -- and applying liberally. A larger quantity of a lower-SPF sunscreen could protect you more than a small amount of one with a higher SPF. You need a teaspoon for each limb, a teaspoon for the face, and a teaspoon each for the back and chest. As for the number on the bottle, "SPF 30 is more than adequate in terms of providing the necessary protection," Mr. Sinclair notes. This is true for everyone, he says -- including children.
Your room key has your credit card information on it.
These days, most people are concerned about the security of their credit card information, whether they are giving it to a waiter or shopping over the Internet. But are we ignoring another potential way for our data to find its way into the wrong hands -- hotel room key cards? Quite apart from the possibility of losing such card-keys, most people also habitually hand them back when they check out -- and they get reused by hotels. If there is credit card data on there and it found its way into the hands of, say, an unscrupulous hotel employee, that would pose a big security risk.
Hotels, however, say this isn't the case, pointing out that there really isn't any reason to put a credit card number on a key. (Check-in staff already have your credit card number, remember?) Angus Stevenson-Hamilton, director of corporate security for Shangri-La Hotels & Resorts, says, "It's only a card for access to a hotel room," with just the room number and dates of stay encoded on it. So it doesn't matter, he says, whether you hand it over or toss it when you check out.
Tommy Y.C. Leung, managing director of Hong Kong and Greater China for VingCard Elsafe, a division of Swedish lock systems manufacturer Assa Abloy AB, walked us through the process of coding a key card. When check-in staff code a key card for a guest, the hotel's key software system allows them to input a room number, check-in and check-out dates and times, and possibly a guest's name. However, VingCard Elsafe, which provides electronic locking systems to hotels, says its key coding software doesn't allow hotel employees to put credit card information on a card. (Think of the software as a form on a computer screen, with different fields for different information. There's no field for a credit card number.)
With VingCard Elsafe's help, Weekend Journal tried reading key cards from five hotels in four countries. In all cases, the result was the same: We couldn't read them. That's because hotels have their own individual software for encoding cards. You can't insert a card from Hotel A into a reader from Hotel B and get any readable information from it.
Squat toilets are less hygienic than raised ones.
Not so: "Squatting is cleaner than raised toilets in the sense that you don't have to be in contact with the seat cover," says Jack Sim, Singapore-based founder of the World Toilet Organization, a nonprofit body that promotes better toilet standards. The primary risk that a squat toilet poses to a person using one is actually injury by falling, he says, and suggests practice and exercise in anticipation of a trip where squat toilets may be the only option.
Even sit-down toilets aren't a major health risk, adds Helen Oh, senior consultant at Changi General Hospital's Medical Centre for International Travellers in Singapore. Skin contact isn't a very effective method of germ transmission compared with inhalation or ingestion, she says, because germs can't easily enter unbroken skin.
With either type of toilet, if you're worried about something splashing you, throw some toilet paper in before you use it; the paper will absorb the splash. But the most important thing is to wash your hands with soap afterward.
Avoid eating melons in developing countries.
Some people think that given their high water content and the fact that they grow next to the ground, melons are more likely than other fruit to harbor bacteria. Not necessarily, says Dr. Oh. With any fruit that is cut up before it's served, she says, there could be a risk that it was washed with nonpurified water or cut with contaminated utensils: "That's why we always advise travelers not to eat cut fruit, but to eat fruit that you peel and you cut yourself," she says. Soil contaminants on a melon's rind could be transferred to the flesh during cutting -- which could happen anywhere.
So why do melons get a bad rap? Melons have to be cut up to be served, says Dr. Oh, noting that "melon is a huge fruit."
If the ice in your drink is round with a hole, that means it has been made in an ice machine that purifies the water -- and is safe to drink.
This one doesn't hold water, say hotel food and beverage staff and travel-health specialists. There's no correlation between ice shape and whether it's safe to consume. Mark Holmes, executive assistant manager, food and beverage for the Grand Hyatt Hong Kong, says he's "never heard of" of the correlation between the shape of the ice and its safety. "It sounds a bit strange." Ice machines may simply be attached to a tap and use whatever water comes out, and while some ice-makers have built-in water purifiers, others don't. There's no way of telling which type an establishment is using without asking. While it might not be particularly novel, the old advice is still the best advice: Stick to bottled water. And if you're worried, ask for that drink without ice.
走出旅行知识误区
旅游可以带来欢乐，这就是我们为何出游的原因，但它也可以给我们带来焦虑。几乎每一位旅行者在出发前夕都会在内心滋生出对健康和安全的忧虑。这些忧虑各种各样：坐经济舱是否会得上深静脉血栓？我的防晒霜能否完成任务？为了避免闹肚子，是否不要让酒吧招待在色彩艳丽的鸡尾酒中放冰？
此外，还有航班延误、当地饭菜中看不中吃、语言障碍等各种各样的担忧。随著新开通的航线能把游客带到更远的目的地，游客恐怕还会担心禽流感等传染病。总而言之，担心的理由看起来五花八门。
对于经常旅行的游客来说，有必要知道哪些是必须提防的，而哪些是杞人忧天的。为了帮你做好正确的预防措施同时又不必得上旅行恐惧症，《华尔街日报》周末版咨询了一些专家，如航空学者、微生物学家、酒店安全专家，甚至还包括一位如厕方面的权威。我们的使命是：辨析一些大家在旅行途中都会碰到的健康和安全问题，判断哪些是无稽之谈、哪些是金玉良言。
出现空难的时候坐在飞机的后部可能会救你一条命
没错－－前提是这是一起能够让坐在飞机后部的乘客存活下来的事故。美国航空管理局(Federal Aviation Administration)的座舱安全学者帕默顿(David Palmerton)解释说，飞行事故千差万别，每次事故都会产生不同的影响。在决定哪个部分的座位最为安全时要具体事故具体分析。例如，机身最坚固的部分往往是在机翼与机体连接处。但机翼往往也是燃油所在之处，因此发生事故时火势会率先蔓延到机翼那里。
虽然有那么几次事故中，幸存下来的是坐在飞机后部的乘客，但帕默顿说，我可以给你举出相同数量的前排乘客生还的事故例子。增加你生还几率的最好方法就是：每次登机的时候留意一下离你最近的逃生出口。
无论如何，即便发生了最坏的事情，你仍可能幸运脱险。有关飞机失事最无稽的说法之一就是：只要你登上了飞机，你出事的概率就增加了。而根据美国全国运输安全委员会(U.S. National Transportation Safety Board)的统计数据，1986至2005年间，美国航空公司发生的719起客机及货机事故中，造成人员死亡的只有72起，占总数的10%。
经济仓的乘客更容易得上深静脉血栓
虽然深静脉血栓有另外一个别名叫经济仓综合症，但并没有确凿的证据表明它与乘坐经济仓有联系。据医学杂志South African Medical Journal在2003年刊登的一项研究显示，人的血栓水平与乘坐的仓位等级并没有关系。
世界卫生组织(World Health Organization)一个名为Scientific Executive Committee的委员会专门研究乘坐飞机与血栓的关系，该委员会主席克斯特温(Patrick Kesteven)表示，到目前为止，还没有哪项研究得出结论，说飞机尾部乘客患上深静脉血栓的几率更大，乘坐头等仓和商务仓的乘客也有得深静脉血栓的。他说，尼克松(Richard Nixon)也得了深静脉血栓，“但我敢打赌他在飞机上的座位肯定十分宽敞。”（这位美国前总统备受静脉血栓的病痛折磨，他在1974年的日记中写道，他是在去夏威夷的途中被诊断出患有血栓的。）
研究人员肯定了一点，那就是缺乏运动会导致血栓。三周前刊登在英国医学杂志《柳叶刀》(The Lancet)的一项最新研究称，飞机机舱内的低压缺氧环境等其他因素也可能是造成血栓的元凶。
不过，荷兰Leiden大学医学中心(Leiden University Medical Center)的医生卡内吉亚特(Suzanne Cannegieter)表示，现在也还不能肯定这些因素就是导致血栓的原因。她是上述研究的作者之一。她说，至于座位问题，似乎从理论上看蜷缩在经济仓中可能比躺在头等仓座椅上更不利于血液循环。不过，尚无研究证明该结论的真实性。顺便说一句，深静脉血栓病例的死亡率只有1%左右。
最好的办法就是：不时在机舱内来回走动。
机舱的空气里充满了细菌
人们对禽流感和非典型肺炎(SARS)的担忧将这个问题推到了前面。不过，飞机真的比办公室、电梯更不卫生吗？机仓中的一半空气来自外部，另一半是循环空气。因此，你在飞机上吸入的氧气中有一半夹杂著他人呼出的气体。
不过，这部分循环空气会通过一个高效的特制空气过滤装置过滤，它一般都能消灭几乎所有的有害细菌，香港大学微生物系的系主任袁国勇说。机舱内的空气会频繁地进行过滤。如果飞机保养良好，机舱内的空气每小时会更换20次，这样的空气流通水平与医院手术室差不多。袁国勇同时还说，一般写字楼的空气更换速度也只有每小时5次左右。
医生称，飞机上的空气不是问题。问题是其他乘客可能会长时间与你近距离接触，袁国勇说。在长途飞行过程中，病菌更容易在邻近的乘客间相互传染。如果恰好坐在一个病人旁边该怎么办？袁国勇建议说，如果有可能，最好调换到别的座位上。
为了调整长途飞行带来的时差，最好在飞机上睡觉，并尽快调整到当地时间，在落地的时候不要小睡。
这些说法基本正确。新加坡中央医院(Singapore General Hospital)睡眠紊乱科的副主任Lim Li Ling建议，在倒时差的第一天尽量不要小睡，否则你会一觉睡上很长时间。如果你想打个盹，最好是在上午或是中午的时候，香港中文大学(Chinese University of Hong Kong)睡眠检查室的Y.K. Wing说。如果小睡时间过长，或是太迟，你将很难调整到新的时区。
一上飞机就立即将手表的时间调整到新的时区，在飞行过程中尽量按照新时区的时间睡觉吃饭，Lim说。她说，有时候在飞机上睡觉并不是最好的解决办法。如果你是在半夜到达目的地，在飞机上就不要睡觉了，这样你一著陆就能进入睡眠状态了。
你还应该大量喝水，避免摄入咖啡因和酒精，在飞机上还要少吃东西，以避免身体在不适应的时候消化大量食物。Lim说，旅行者可以服用褪黑激素来帮助自己调整时差。
SPF值越高，防晒效果越好
从理论上讲是这样，但是人们很少足量使用，因此通常达不到瓶子上描述的效果，澳大利亚癌症委员会国家皮肤癌中心的辛克莱(Craig Sinclair)说。SPF值在理论上是一种衡量你享受日光浴多久后不会被晒伤的指标，举例来说，SPF 20的防晒霜其保护效果应该相当于SPF 10的两倍。在实验室的测试环境下的确如此，但是在防晒霜通常得不到足量涂抹的现实世界里，情况就另当别论了。事实上，SPF值较高的防晒霜的确可以隔离更多的紫外线B(UVB)，但是差别并不大：在实验室环境下，SPF 30的UVB隔离率为96.7%，而SPF 50为98%，辛克莱说。
真正的窍门在于，要每隔两个小时涂抹一次，而且要足量涂抹，新加坡国家皮肤中心(National Skin Centre in Singapore)的皮肤科医生Colin Theng说。对低SPF值的防晒霜增加用量，其保护效果要好于少量涂抹高SPF值防晒霜的效果。你要在脸部、手臂、背部和颈部全部涂满。至于瓶子上的SPF数字，“SPF 30就足以让你得到必要的保护了，”辛克莱表示。这一点适用于所有人－－包括儿童。
房间钥匙中可能包涵你的信用卡信息
外出旅游的日子里，多数人都会担心信用卡信息的安全性，无论是将信用卡交给侍者还是在网上购物，人们总是小心翼翼。但我们是不是忽略了另外一种可能泄漏数据的途径呢？－－酒店房间的钥匙卡。除了出现丢失钥匙卡的情况，人们大多会在结帐时习惯性地把它交回酒店，这样，钥匙卡就会被酒店重复使用。如果钥匙卡中包涵你的信用卡信息，而它又落到了酒店里不太道德的员工手中，那可是一个不小的风险。
但酒店方面表示，这种情况绝对不会发生。他们说，事实上他们没有理由把房客的信用卡号放在钥匙里。（不要忘了，帮你登记入住的人早就有了你的信用卡号。）Shangri-La Hotels & Resorts的公司安全部负责人汉密尔顿(Angus Stevenson-Hamilton)表示，“这只是一个进入酒店房间的钥匙卡，”上面只记载你的房间号和入住时间。因此无论你是交回酒店还是把它丢掉，都无所谓。
VingCard Elsafe负责香港和中国大陆业务的Tommy Y.C. Leung带领我们领略了给钥匙卡加密码的全过程。酒店登记人员给房客的钥匙卡加密时，软件系统会要求他们输入房间号，登记入住和结帐的日期及时间，还可能包括房客的名字。但是为酒店提供电子锁系统的VingCard Elsafe称，加密软件并没有让酒店员工在钥匙卡中输入信用卡信息。而且根本不存在输入信用卡号的位置。
在VingCard Elsafe的帮助下，本刊曾经尝试在4个国家的5个酒店中读取一个钥匙卡的信息。但结果无一例外：我们无法读取数据。因为酒店的加密软件各不相同。你无法把A酒店的钥匙卡插到B酒店的读卡器中读数。
蹲便不如坐便卫生
“蹲便比坐便干净，因为你无需接触到坐便器，”这种观点大错特错，World Toilet Organization的新加坡创始人西姆(Jack Sim)说。他说，蹲便的最大风险是，如厕时你可能摔倒并且受伤，他说，如果旅行目的地只有蹲便，那么游客们最好先提前练习一下。（World Toilet Organization是一家推广优质马桶标准的非盈利性组织。）
新加坡樟宜综合医院(Changi General Hospital)国际游客医疗中心的高级顾问Helen Oh补充称，坐便的健康风险并不大，与直接吸入相比，皮肤接触并不易于细菌传播，细菌很难穿过完好的皮肤。
无论用哪种马桶，如果你担心有什么东西会溅到你，可以在你如厕前扔一些厕所纸在里面；它会吸收可能溅出的液体。但最重要的是，如厕后一定要用洗手液将手洗干净。
不要在发展中国家吃西瓜
由于西瓜富含水分并且生长在土壤表面，很多人认为西瓜可能潜藏著大量细菌。不尽然，Helen Oh说。她说，对于任何需要切割后方可食用的水果，都存在未用纯净水洗过或者接触过不干净器具的风险。“所以我们总要告诫游客不要吃切好的水果，要亲自剥皮或者亲自切，”她说。留在西瓜皮上的土壤污染物可能在切西瓜的时候被转移到西瓜果肉中－－这种情况比比皆是。
所以你可以想像为什么西瓜不受欢迎。西瓜必须被切开方可食用，Helen Oh说，“西瓜太大了。”
如果你杯中饮料里的冰块是圆圆的，上面有一个洞，那么它一定来自制冰机，所用水源是安全的纯净水。
这也未必站得住脚，酒店食品和饮料供应员以及旅游健康专家说。冰块形状与它是否可以安全食用毫无关系。Grand Hyatt Hong Kong的食品和饮料供应负责人霍姆斯(Mark Holmes)表示。他说，他“从未听说”冰块的形状与它安全与否存在必然联系。“这听起来太怪了，”制冰机可能被简单地连接到水龙头，直接使用水龙头里流出的水，至于冰块制造者是否安装了净水器，那就不得而知了。如果你不刨根问底，谁会知道他们究竟装上了什么设备？给你的忠告还是那句老话：一定要喝瓶装水。如果你对冰块不放心，就不要往饮料里加冰。
