首页
外语
计算机
考研
公务员
职业资格
财经
工程
司法
医学
专升本
自考
实用职业技能
登录
外语
Polluted water is nothing new in the United States. We have lived through flaming rivers and caustic creaks that could take the
Polluted water is nothing new in the United States. We have lived through flaming rivers and caustic creaks that could take the
admin
2013-06-17
41
问题
Polluted water is nothing new in the United States. We have lived through flaming rivers and caustic creaks that could take the hide off a hound. For decades, however, efforts to safeguard drinking water were hampered because no one had an accurate sense of the full range of contaminants in the water supply, nor of the geographic extent of the pollution. This year two separate research teams unveiled sophisticated new tools to find out exactly what chemical dangers are lurking in freshwater streams.
"Research in Europe in the 1990s showed that pharmaceuticals were turning up in the water," says Dana Kolpin, leader of a U. S. Geological Survey Water Resources Division research ream that developed five new analytic methods for measuring water contaminants." Our big effort was to develop methods to measure very small amounts of organic chemicals. ’ The research team fanned out across 30 states nationwide and conducted two years of sampling from 139 streams. They were chosen, says Kolpin, on the basis of their location downstream from" intense urbanization and livestock production." In a study published in the March 15 Journal of Environmental Science & Technology, Kolpin and his colleagues reported they looked for 95 different contaminants, such as antibiotics, steroids, hormones, antioxidants, plasticizers, and various solvents. They found 82 of them. Nearly 80 percent of the streams showed one or more of the contaminants. The median stream contained seven. Even the good news--that the most frequently detected contaminants like fecal steroids, cholesterol, insect repellent, caffeine, disinfectant, fire retardant, and detergents were found in generally low concentrations--had to be qualified. Many of those compounds have no guidelines for safe amounts, and little is known about the effects of chronic exposure or the interactive effects of compounds that have been detected together.
In a related Environmental Protection Agency study that is still in progress, a team of scientists at the Johns Hopkins Whiting School of Engineering is using gas chromatography and mass spectrometry to detect the presence of various anticonvulsants and anticancer drugs in drinking water. Led by Lynn Roberts and Ed Bouwer, the researchers track samples at sewage-treatment facilities in Massachusetts and Maryland to determine whether and in what quantities pharmaceuticals are getting through the waste-treatment plants and the extent to which they may be accumulating in coastal waters.
The goal of both research teams is to provide a baseline of what organic compounds are in the water, in what quantities, and how they are getting there--key steps toward ensuring that the water we drink isn’t killing us.
According to this passage, two research teams ______.
选项
A、have determined the full range of contaminants in the water supply
B、have ascertained the geographic extent of the water pollution
C、have developed new methods to measure water contaminants
D、have succeeded in preventing drinking water from being polluted
答案
C
解析
转载请注明原文地址:https://kaotiyun.com/show/27M7777K
0
大学英语四级
相关试题推荐
Overahundredyearsago,CharlesDickensshockedmanyofhisreaderswhenhedescribedtheconditionsunderwhichyoungchildre
A、Shesawanadinthenewspaper.B、Shelearnedaboutitfromafriend.C、Sheheardaboutitduringatelevisioninterview.D、Sh
Forthispart,youareallowed30minutestowriteacompositiononthetopicMeasurestoRelieveTrafficJaminthreeparagraph
Manyteachersbelievethattheresponsibilitiesforlearningliewiththestudents.【C1】______alongreadingassignmentisgiven,
Severalrecentstudieshavefoundthatbeingrandomly(随机地)assignedtoaroommateofanotherracecanleadtoincreasedtoleran
Shoppingforclothesisnotthesameexperienceforamanasitisforawoman.Amangoesshoppingbecauseheneedssomething.
Researchershaveestablishedthatwhenpeoplearementallyengaged,biochemicalchangesoccurinthebrainthatallowittoact
Themostexcitingkindofeducationisalsothemostpersonal.Nothingcanexceedthejoyofdiscoveringforyourselfsomething
Wethinkitnecessary______.(让人们充分认识违反交通规则的危害)
A、Thewomanhastroubledtheheadmaster.B、Thewomanhasnottroubledtheheadmaster.C、Theheadmasterhasnotbeenbusythismo
随机试题
这个标志的含义是警告前方道路易滑,注意慢行。
简述责任成本与产品变动成本结合核算形式的做法。
以下有关计算机病毒的描述,不正确的是___________。
除专用合同条款另有约定外,因变更引起的价格调整约定有()。
甲公司的资质等级为二级,而某工程项目需要一级资质的承包商承建,于是甲公司就借用了乙公司的资质证书,承揽了该工程,后来因工程质量不合格而给发包人造成了重大损失。请问,赔偿责任应当由()承担。
注册会计师在确定审计工作底稿的格式、要素和范围时应考虑的因素中恰当的有()。
坚持对外开放的基本国策必须坚持“引进来”和“走出去”同时并举、相互促进的开放战略,不断提高对外开放水平,具体有()
Thewaysinwhichsocietiesaddressenvironmentalissuesareinthemidstofaprofoundtransformation.Boththeextentofthis
Comeandseemewhenever______.
BostonWeeklyOutlookMondayTuesdayWednesdaySunnyPartlyCloudyLightR
最新回复
(
0
)