6-13 肥胖症与驾车的危险性（在线收听）

Obesity and Risk in Driving

Heavier people are more likely to be killed or seriously injured in car accidents than lighter people, according to new research.

That could mean car designers will have to build in new safety features to compensate¹ for the extra hazards² facing overweight passengers. In the US, car manufacturers have already had to redesign air bags so they inflate³ to lower pressures, making them less of a danger to smaller women and children. But no one yet knows what it is that puts overweight passengers at extra risk.

A study carried out in Seattle, Washington, looked at more than 26,000 people who had been involved in car crashes, and found that heavier people were at far more risk. People weighing between 100 and 119 kilograms are almost two-and-a-half times as likely to die in a crash as people weighing less than 60 kilograms.

And importantly, the same trend held up when the researchers looked at body mass index⁴ (BMI) -- a measure that takes height as well as weight into ac count. Someone 1.8 metres tall weighing 126 kilograms would have a BMI of 39, but so would a person 1.5 metres tall weighing 88 kilograms. People are said to be obese⁵ if their BMI is 30 or over.

The study found that people with a BMI of 35 to 39 were over twice as likely to die in a crash compared with people with a BMI of about 20. It is not just total weight, but obesity itself that's dangerous.

While they do not yet know why this is the case, the evidence is worth pursuing, says Charles Mock, a surgeon and epidemiologist⁶ at the Harborview Injury Prevention and Research Center in Seattle, who led the research team. He thinks one answer may be for safety authorities to use heavier crash? test dummies⁷ when certifying cars as safe to drive.

Crash tests normally use dummies that represent standard? sized males weighing about 78 kilograms. Recently, smaller crash? test dummies have also been used to represent children inside crashing cars. But larger and heavier dummies are not used.

The reasons for the higher injury and death rates are far from clear. Mock speculates that car interiors might not be suitably designed for heavy people. Besides, obese people, with health problems such as high blood pressure or diabetes⁸, could be finding it tougher to recover from injury.

Richard Kent, an expert in impact biomechanics⁹ at the University of Virginia, thinks the new research has established a legitimate¹⁰ connection between obesity and severe injury or death. Because the research used BMI data, it has not confused taller (and therefore heavier than average) people with those who are overweight.

People who are obese might also be at risk because seat belts do not hold them as securely in a crash. “For example, a large amount of fat tissue between the restraint system and the bony thorax¹¹ acts much like a winter coat: it introduces ‘slack’ into the restraint system and decreases its performance,” Kent says.

注释：

1.compensate [5kCmpEnseit] vi. 抵消；弥补

2.hazard [5hAzEd] n. 危险；危险之源

3.inflate [in5fleit] vi. 充气；膨胀

4.index [5indeks] n. 指数；指标

5.obese [Eu5bi:s] a（过分）肥胖的

6.epidemiologist [5epi7di:mi5ClEdVist] n. 流行病学家

7.dummy [5dQmi] n. 假人；人体模型

8.diabetes [7daiE5bi:ti:z] n. [医] 糖尿病

9.biomechanics [7baiEumE5kAniks] [复] n. 生物力学；生物机械学

10.legitimate [li5dVitimEt] a. 正当的，合理的；合乎逻辑的

11.thorax [5WC:rAks] n. [解] 胸；胸廓

肥胖症与驾车的危险性

根据最新的研究，体重较重的人较之体重较轻的人更可能在车祸中死亡或负重伤。

这可能意味着汽车设计者必须加进新的安全装置，以抵消体重过重的乘客面临的额外风险。在美国，为了减少瘦小的妇女和儿童的危险，汽车制造商已经对安全气囊进行了必要的重新设计，使其膨胀压力有所减弱。但是还没有人知道是什么使胖人面临额外的危险。

在华盛顿州西雅图进行的一项研究对遇过车祸的2.6万多人进行了调查，结果发现胖人的危险远远超过正常人。体重介于100到119公斤的人在车祸中丧生的可能性几乎是体重在60公斤以下的人的2.5倍。

还有一个重要事实：研究者通过观察人体综合指数（BMI），即将身高和体重综合考虑的一种算法，验证了这一趋势。一个身高1.8米、体重126公斤的人其BMI为39，而一个1.5米高、88公斤的人也是如此。如果一个人的BMI达到或超过了30，他就被认为是患有肥胖症。

研究发现BMI介于35到39之间的人，其在车祸中死亡的可能性是BMI大约为20的人的两倍。因此，是肥胖症本身而不仅仅是体重构成了危险。

西雅图港景创伤预防与研究中心外科医生及流行病专家、本项研究课题的领头人查尔

斯·莫克说，虽然他们尚不知晓导致这种现象的原因，但已有的迹象是值得研究的。他认为，安全部门在检验汽车安全性能时，也许可以用更重的假人做撞击测试。

人们在进行撞击测试时使用的假人通常是按照体重为78公斤左右的男性标准体型制作的。最近，较小的测试假人也投入了使用，以模拟车祸发生时坐在车内的儿童。但是还没有人采用更大、更重的假人进行测试。

胖人在车祸中有较高的受伤率和死亡率，其原因尚不清楚。莫克推测，汽车的内部设计或许不适合于胖人。此外，患有高血压或者糖尿病的肥胖者，受伤后较难康复。

弗吉尼亚大学研究撞击生物力学的专家理查德•肯特认为，新的研究已经在肥胖症与重伤或死亡之间建立起了一种合理的关联性。由于研究采用了BMI数据，它没有将高个子（因此体重高于平均值）与超重者相混淆。

发生车祸时安全带对肥胖者起不到安全作用，这也可能使他们处于危险之中。肯特说：“比如，安全带和多骨的胸腔之间的大量脂肪组织就像是一件冬天的大衣——它使安全带‘松弛’，从而减弱了安全带的作用。”