'Gender-bending' fear over plastic drinks bottles 长期饮用塑料瓶装水使人“不男不
文章来源: 文章作者: 发布时间:2009-06-01 00:55 字体: [ ]  进入论坛
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Drink from plastic bottles can raise the body’s levels of a controversial ‘gender-bending’ chemical by more than two thirds, according to tests.

Experts have been concerned about the possible health effects of bisphenol A (BPA) - an everyday chemical used in many plastic food and drink containers and tins as well as clear baby bottles - which is officially classified as toxic1 in some countries.

A study found that participants who drank for a week from polycarbonate bottles showed a 69 per cent increase in their urine of BPA, which mimics2 the female sex hormone3 oestrogen.

Researchers did not say how much liquid was drunk per day. Researchers from Harvard School of Public Health studied 77 students, who had first undergone a seven-day ‘washout’ phase in which they drank all cold beverages4 from stainless5 steel bottles in order to minimise BPA exposure.

They were then given two polycarbonate bottles and asked to drink all cold beverages from them during the next week. Previous studies have suggested that high levels of BPA consumption are linked to birth defects, growth problems and an increased risk of heart disease and diabetes6.

In particular there are fears that heating the bottles, as parents would do when warming their baby’s milk, causes the chemical to leak in potentially dangerous quantities into the liquid contained within.

The senior author of the latest study, Karin B. Michels, associate professor of epidemiology at HSPH and Harvard Medical School, said: "We found that drinking cold liquids from polycarbonate bottles for just one week increased urinary BPA levels by more than two-thirds."

"If you heat those bottles, as is the case with baby bottles, we would expect the levels to be considerably7 higher. This would be of concern since infants may be particularly susceptible8 to BPA’s hormone gland-disrupting potential."  Canada banned the use of BPA in polycarbonate baby bottles last year and some manufacturers have voluntarily eliminated it from their products.

Most adults carry BPA in their bodies but expert opinion on the risks is divided. The European Food Safety Authority believes that people naturally convert the chemical into less harmful substances in the body.

Previous studies had found that BPA could leach9 from polycarbonate bottles into their contents, but this study - published in US journal Environmental Health Perspectives - is the first to show the size of the corresponding increase in urinary BPA concentrations in humans.

Harvard researcher Jenny Carwile said: ‘While previous studies have demonstrated that BPA is linked to adverse10 health effects, this study fills in a missing piece of the puzzle - whether or not polycarbonate plastic bottles are an important contributor to the amount of BPA in the body.’

研究显示,饮用塑料瓶装水可使人体内颇具争议的“性别偏移”化学物质含量提升超过三分之二。

专家对双酚A(BPA)可能对人体健康造成的影响表示担忧,这是很多食品和饮料塑料包装盒、易拉罐、以及透明奶瓶中所含的常规化学成分,而一些国家已将该物质正式列为有毒物质。

研究显示,被调查者饮用PC(聚碳酸酯)塑料制成的瓶装水一周后,尿液中BPA的含量会增加69%,而BPA类似于雌性激素。

研究人员没有阐明被调查者每天喝多少液体。来自哈佛公共卫生学院的研究人员对77名学生进行了调查,这些被调查者首先要进行为期一周的“冲洗”,在此期间,为尽量不接触BPA,他们只能喝不锈钢水瓶装的冰饮料。

之后研究人员给被调查者两个PC塑料瓶,并要求他们在接下来的一周内,只用这种水瓶喝冰饮料。此前研究已证实,BPA摄入量高与出生缺陷、发育问题以及心脏病和糖尿病患病风险高有联系。

特别需要指出的是,加热塑料瓶会造成更大危害。例如当家长使用塑料瓶给宝宝热牛奶时,有一定量的潜在危险性化学物质会渗透进瓶内液体中。

该项最新研究的资深作者、哈佛公共卫生学院和医学院的流行病学副教授卡利文•B•米歇尔说:“我们发现,使用PC塑料制造的水瓶喝冷水仅一周,尿液内的BPA含量就会增长超过三分之二。”

“我们认为,当你加热塑料瓶,比如热牛奶时,这种物质的含量会相当高。BPA有可能扰乱腺体激素分泌,婴儿对此极其敏感,因此我们对此应更加注意。”加拿大于去年禁止在生产PC塑料奶瓶时使用BPA,一些制造商主动从产品中去掉了该成分。

大多数成年人体内都携带有BPA,但对于该物质的危害性,专家的看法却有分歧。欧洲食品安全局称,人体会将该化学物质自动转化为危害较小的物质。

此前研究证实,BPA可以从PC塑料瓶体渗入所装液体内,但发表在《美国环境卫生展望》期刊上的这份研究首次证实了(使用PC塑料瓶饮水后)人体尿液中BPA浓缩物增加的对应含量。

哈佛大学研究人员珍妮•卡维尔说:“此前研究已证实BPA对健康有副作用,而这项研究填补了这种推断的空白---也就是PC塑料瓶是否是人体内BPA含量增高的罪魁祸首。”

 Vocabulary:

mimic:to be an imitation of; simulate; resemble closely(与...极相似;呈现...的形象)

susceptible:accessible or especially liable or subject to some influence, mood, agency, etc(易受影响的,易得病的)



点击收听单词发音收听单词发音  

1 toxic inSwc     
adj.有毒的,因中毒引起的
参考例句:
  • The factory had accidentally released a quantity of toxic waste into the sea.这家工厂意外泄漏大量有毒废物到海中。
  • There is a risk that toxic chemicals might be blasted into the atmosphere.爆炸后有毒化学物质可能会进入大气层。
2 mimics f8207fb5fa948f536c5186311e3e641d     
n.模仿名人言行的娱乐演员,滑稽剧演员( mimic的名词复数 );善于模仿的人或物v.(尤指为了逗乐而)模仿( mimic的第三人称单数 );酷似
参考例句:
  • Methods:Models were generate by CT scan,Mimics software and Abaqus software. 方法:采用CT扫描,Mimics软件和Abaqus软件的CAD进行三维有限元模型的创建。 来自互联网
  • Relaxing the mind and body mimics the effect that some blood-pressure pills would have. 放松身心会产生某些降压药才能产生的效果。 来自辞典例句
3 hormone uyky3     
n.荷尔蒙,激素,内分泌
参考例句:
  • Hormone implants are used as growth boosters.激素植入物被用作生长辅助剂。
  • This hormone interacts closely with other hormones in the body.这种荷尔蒙与体內其他荷尔蒙紧密地相互作用。
4 beverages eb693dc3e09666bb339be2c419d0478e     
n.饮料( beverage的名词复数 )
参考例句:
  • laws governing the sale of alcoholic beverages 控制酒类销售的法规
  • regulations governing the sale of alcoholic beverages 含酒精饮料的销售管理条例
5 stainless kuSwr     
adj.无瑕疵的,不锈的
参考例句:
  • I have a set of stainless knives and forks.我有一套不锈钢刀叉。
  • Before the recent political scandal,her reputation had been stainless.在最近的政治丑闻之前,她的名声是无懈可击的。
6 diabetes uPnzu     
n.糖尿病
参考例句:
  • In case of diabetes, physicians advise against the use of sugar.对于糖尿病患者,医生告诫他们不要吃糖。
  • Diabetes is caused by a fault in the insulin production of the body.糖尿病是由体內胰岛素分泌失调引起的。
7 considerably 0YWyQ     
adv.极大地;相当大地;在很大程度上
参考例句:
  • The economic situation has changed considerably.经济形势已发生了相当大的变化。
  • The gap has narrowed considerably.分歧大大缩小了。
8 susceptible 4rrw7     
adj.过敏的,敏感的;易动感情的,易受感动的
参考例句:
  • Children are more susceptible than adults.孩子比成人易受感动。
  • We are all susceptible to advertising.我们都易受广告的影响。
9 leach uxCyN     
v.分离,过滤掉;n.过滤;过滤器
参考例句:
  • Liquid water can leach soluble materials from the interface.液态水能够从界面溶解出可溶性物质。
  • They believe that the humic materials are leached from decaying plant materials.他们认为腐植物料是从腐烂的植物体浸沥而来。
10 adverse 5xBzs     
adj.不利的;有害的;敌对的,不友好的
参考例句:
  • He is adverse to going abroad.他反对出国。
  • The improper use of medicine could lead to severe adverse reactions.用药不当会产生严重的不良反应。
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