全文预览已结束
下载本文档
版权说明:本文档由用户提供并上传,收益归属内容提供方,若内容存在侵权,请进行举报或认领
文档简介
青年人英语四级考试网: /waiyu/cet4/本篇阅读材料“孕妇暴露于受污染空气将增加孩子发胖几率”选自时代(原文标题为:Exposure to Air Pollution in Pregnancy May Boost Chances of Obesity in Kids 2012.4.17)Its easy to blame parents when young children gain too much weight, but the latest research suggests that certain obesity risk factors are out of Mom and Dads control.In a study published this week in the American Journal of Epidemiology, scientists at the Mailman School of Public Health at Columbia University found that exposure to air pollution during pregnancy may be associated with a greater chance of having heavier kids.Andrew Rundle, an associate professor of epidemiology, decided to study air pollution because he was curious about the role that environmental chemicals known as endocrine disruptors compounds that include BPA, phthalates and parabens play in determining weight. Endocrine disruptors, which mimic naturally occurring hormones like estrogen in the body and interfere with some developmental and metabolic functions, are also found in air pollution; animal studies have shown that mice exposed to estrogen-like compounds in air pollution gain more weight than unexposed mice.Rundle and his colleagues set about tracking air pollution exposure in 702 women in their third trimester of pregnancy, by equipping them with air monitors tucked into backpacks. The women wore the backpacks for 48 hours, except while sleeping or showering, measuring levels of polycyclic aromatic hydrocarbons (PAHs), endocrine-disrupting chemicals found in cigarette smoke and car exhaust. The women, who were recruited from the university hospitals New York City clinics, lived in the neighboring area, including the Bronx and northern Manhattan areas that have heavy car traffic but are not known to have unusual amounts of industry-related pollution.Children born to mothers with the highest PAH levels during their third trimester had a 79% greater risk of becoming obese, compared with children born to moms with the lowest PAH levels. By age 7, the risk was even higher more than 2.25 times greater.Previous studies have linked air pollution to increased risk of heart disease and stroke, and Rundles colleagues have shown that PAH exposure during pregnancy can also increase the risk of behavioral problems in children by age 5 and 7, but this is the first study to link the pollutant to obesity.“Its a fairly big effect,” says Rundle. “Obesity is really, really complicated, and there are different things pushing us in the wrong direction in terms of energy consumption and physical activity. I think we have to embrace the idea that the obesity epidemic is not just about you and me making personal choices that are not good for us, or moms making bad choices for kids. Its a far more complicated problem than that, and environmental chemicals may play a role as one piece of the problem.”Not all of the children whose moms were exposed to the higher levels of PAH became obese, but a significant proportion of them did, and the connection between PAH exposure and obesity remained strong even after Rundles team adjusted for other factors that could influencing factors, including the mothers socioeconomic status, her income, and the median household income of the neighborhood in which the mothers lived. “We went through a long list trying to imagine all the reasons that could bias the relationship or explain it away,” says Rundle. “And after months and months of healthy skepticism, we came to the point of realizing that the data looked really solid.”To ensure that the obese childrens excess weight was due to fat, not added bone or muscle, the researchers measured body fat composition in a subset of 453 children; they found that fat almost exclusively accounted for the childrens heavier weight. That corresponded to animal studies as well, and could hint at how the PAHs are contributing to obesity by disrupting how fat cells are formed and develop during childhood. Normally, most of the fat cells adults have are generated during the first year of life, beginning in utero; weight gain results when these existing fat cells swell in size, not in number. But exposure to potential endocrine disruptors like PAHs could interfere with the normal development of fat cells in infancy, and lead to an increase in fat cells from an early age.Its hard to avoid air pollution, particularly for expectant mothers living in densely populated cities. But it is possible to avoid the worst sources of PAH exposure, such as cigarette smoke. Avoiding smoking while pregnant and asking friends and family to refrain from lighting up can help, but Rundle says its time that more ubiquitous sources of air pollution also be recognized by public health experts and mothers as potentially long-term health hazards. Although Rundles study did not examine whether a childs exposure to PAHs in his first five years of life could have been the driver of obesity rather than the mothers prenatal exposure, the findings still provide hard-to-ignore evidence that breathing in polluted air could have health effects that may last a lifetime.【重点单词及短语】be associated with 与有关be curious about 对好奇的endocrine disruptors 环境激素interfere with 干扰,干涉;妨碍;触动或弄坏;乱动;与抵触set about 着手;开始做tuck into 藏进polycyclic aromatic hydrocarbons (PAHs) 【化】多环芳香烃,分子中含有两个或两个以上苯环结构的化合物,是最早被认识的化学致癌物。explain sth. away 为
温馨提示
- 1. 本站所有资源如无特殊说明,都需要本地电脑安装OFFICE2007和PDF阅读器。图纸软件为CAD,CAXA,PROE,UG,SolidWorks等.压缩文件请下载最新的WinRAR软件解压。
- 2. 本站的文档不包含任何第三方提供的附件图纸等,如果需要附件,请联系上传者。文件的所有权益归上传用户所有。
- 3. 本站RAR压缩包中若带图纸,网页内容里面会有图纸预览,若没有图纸预览就没有图纸。
- 4. 未经权益所有人同意不得将文件中的内容挪作商业或盈利用途。
- 5. 人人文库网仅提供信息存储空间,仅对用户上传内容的表现方式做保护处理,对用户上传分享的文档内容本身不做任何修改或编辑,并不能对任何下载内容负责。
- 6. 下载文件中如有侵权或不适当内容,请与我们联系,我们立即纠正。
- 7. 本站不保证下载资源的准确性、安全性和完整性, 同时也不承担用户因使用这些下载资源对自己和他人造成任何形式的伤害或损失。
最新文档
- 甘肃省天水市秦安县2023-2024学年高考全国统考预测密卷英语试卷含解析
- 湖南省浏阳一中、攸县一中2024年高三适应性调研考试英语试题含解析
- 湖北省黄冈实验学校2023-2024学年高三一诊考试英语试卷含解析
- 2024春期国开电大本科《商务英语3》在线形考(单元自测1至8)试题及答案
- 湖北省孝感一中、应城一中等五校2024年高考英语二模试卷含解析
- 海南省东方市2024年高三第二次调研英语试卷含解析
- 初级(师)卫生资格初级护理师模拟题2021年-真题33002
- 浙江省绍兴名校2024年高三冲刺模拟英语试卷含解析
- 浙江省严州名校2024届高考英语考前最后一卷预测卷含解析
- HJ 590-2010 环境空气 臭氧的测定 紫外光度法(正式版)
- 沪科版七年级下册数学优质公开课课件9.1 第2课时 分式的基本性质及约分
- 胸痛中心培训测试题(网络医院)试题
- Schneider Electric Introduction南京 施耐德电气及中国介绍
- 目标成本测算标准实施细则
- 最新湘教版地理8年级下册第7章第4节《长江三角洲区域的内外联系》市公开课一等奖课件
- 部编版三年级下册语文学情分析(每一课都有)
- 深静脉血栓的介入治疗
- 国家开放大学计算机应用基础(本) 终结性考试试题及参考答案
- DRGS产生与发展
- 给水工程 教学大纲1
- REITs发展国际经验——日本REITs的40年
评论
0/150
提交评论