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
Geology and Health The importance of particular metals in the human diet has been realised within the past few decades, and
Geology and Health The importance of particular metals in the human diet has been realised within the past few decades, and
admin
2010-01-14
109
问题
Geology and Health
The importance of particular metals in the human diet has been realised within the past few decades, and the idea that geology might be related to health has been recognized for a number of elements such as iodine, zinc and selenium. For example, soils with low iodine contents produce crops and animals deficient in iodine. A lack of iodine in the human diet leads to some serious diseases.
The ultimate source of metals within the human body is rocks, which weather into soil, gaining or losing some of their chemical constituents. The crops we eat selectively remove from the soil the elements that they require for growth. The water we drink contains trace elements leached from rock and soil. Thus the geology and geochemistry of the environment have effects on the chemistry and health of plants, animals and people.
So far there is no data to suggest that people living on metal-rich soils experience a potential health hazard. The levels of metals within naturally contaminated soils are generally not high enough to cause serious health problems. Living on metal-rich soils does not represent a health risk unless large quantities of soil are digested or metal-rich dust is inhaled. However, small children are particularly exposed to metal-rich dust topsoil in playgrounds and gardens. They are also the most likely ones to eat potentially dangerous metal-rich soil.
Heavy metals are persistent: they do not break down to other chemicals in the environment. Industrially polluted sites usually undergo intensive clean-up and rehabilitation because heavy metals are a health concern once they enter the food chain. Some trace metals are alleged to cause cancer and are also known to cause poisoning.
In contrast naturally contaminated soils have not been subject to risk assessment studies and rehabilitation measures, despite the fact that they frequently possess metal concentrations well above those of such polluted by humans and above environmental quality criteria.
There is a vital need to understand the potential risks and long-term health effects of living on naturally contaminated soils. Future environmental investigations of naturally polluted soils should concentrate on the potential pathways of metals into the food chain and human body. Geologists should be part of such studies as they can provide the essential background information on rock and soil chemistry as well as the chemical forms of heavy metal pollution.
*
选项
答案
A
解析
第三段涉及的是自然污染的土壤一般情况下对人体不会造成危害。此段首句就提示了这一点:So far there is no data to suggest that people living on metal-rich soils experience a potential health hazard.
转载请注明原文地址:https://www.kaotiyun.com/show/zwhd777K
本试题收录于:
职称英语理工类基础题库职称英语分类
0
职称英语理工类基础
职称英语
相关试题推荐
Strawberries:Inastudythattrackedthedietsandhealthof1,271peopleinMassachusetts,researchersattheHarvardSchool
"Muchofthesicknessanddeathattributedtothemajorcommunicablediseasesisinfactcausedbymalnutritionwhichmakesthe
Medicinedependsonotherfieldsforbasicinformation,particularlysomeoftheirspecializedbranches.
Thetownisfamousforits(magnificent)buildings.
ChangesofWomen’sRoleTheroleofwomeninBritainhaschangedalotinthiscentury,(51)inthelasttwentyyears.Them
SomeThingsWeKnowaboutLanguageManythingsaboutlanguageareamystery,andmanywillalwaysremainso.Butsomethings
SleepLetsBrainFileMemoriesTosleep.Perchancetofile?FindingspublishedonlinethisweekbytheProceedingsoftheNa
A.beforethecancercellsspreadelsewhereB.themorechancesofdyingofX-rayradiationhewillhaveC.whatismostrespons
Malnutrition"Muchofthesicknessanddeathattributedtothemajorcommunicablediseasesisinfactcausedbymalnutritio
Hundredsofbuildingswere(wrecked)bytheearthquake.
随机试题
混合捻制的铜丝绳性能较好,在吊重使用较多,且制作容易,价格低。
黄热病只在哪个地区流行
脾胃虚寒,风冷相乘,心痛,吐利转筋,治疗应选用()
对于政策性保险,在保险费的缴纳和保险金的给付方面,不遵循利益对等的原则。()
直径为D的实心圆轴,两端受扭转力矩作用,轴内最大切应力为τ。若轴的直径改为D/2,则轴内的最大切应力变为()。
甲公司为了降低生产过程中的废品率,请专家对新上岗的工人进行了质量培训,这种培训支出属于()。
以“茉莉鸡丝汤”为席尾压台戏的酒家是()。
“初中生物教材理论知识归纳概括和拓展的研究”属于()。
背景材料:改革开放以来。农村经济稳步发展。农民收入稳步提高,但是农村文化发展却相对落后。农村文化建设落后于城市文化建设。特别是农村基层文化资源严重匮乏,文化活动形式单一枯燥,缺乏创新。大部分文化站由于受现有场地、经费的限制。文化设施被随意挤占、挪用,导致正
简述陈鹤琴的“活教育”思想。
最新回复
(
0
)