在线观看亚洲精品专区-在线观看亚洲免费-在线观看亚洲免费视频-在线观看亚洲欧美-欧美freexxx-欧美free嫩交video

食品伙伴網(wǎng)服務(wù)號(hào)
 
 
當(dāng)前位置: 首頁 » 專業(yè)英語 » 專業(yè)知識(shí) » 正文

Heavy metals

放大字體  縮小字體 發(fā)布日期:2007-05-28
核心提示:Heavy metals arenatural components of the Earth's crust. They cannot be degraded or destroyed. To a small extent they enter our bodies via food, drinking water and air. As trace elements, some heavy metals (e.g. copper , selenium , zinc ) are essent

Heavy metals are natural components of the Earth's crust. They cannot be degraded or destroyed. To a small extent they enter our bodies via food, drinking water and air. As trace elements, some heavy metals (e.g. copper, selenium, zinc) are essential to maintain the metabolism of the human body. However, at higher concentrations they can be toxic. Heavy metal poisoning could result, for instance, from drinking-water contamination (e.g. lead pipes), high ambient air concentrations near emission sources, or intake via the food chain.

Heavy metals are dangerous because they tend to bioaccumulate. Bioaccumulation means an increase in the concentration of a chemical in a biological organism over time, compared to the chemical's concentration in the environment. Compounds accumulate in living things any time they are taken up and stored faster than they are broken down (metabolized) or excreted.

Still, food poisoning from heavy metals is very rare and in most cases only occurs after environmental pollution. The most well-known example of such an environmental pollution occurred in Japan between 1932-55.

Since 1932 sewage containing mercury was released by Chisso's chemicals works into Minimata Bay in Japan. The mercury accumulates in sea creatures, leading eventually to mercury poisoning in the population. In 1952, the first incidents of mercury poisoning appear in the population of Minimata Bay in Japan, caused by consumption of fish polluted with mercury. In total 500 fatalities were recorded in the 1950s. Since then, Japan has had the strictest environmental laws in the industrialised world and the disease is known as the Minamata Syndrome

更多翻譯詳細(xì)信息請(qǐng)點(diǎn)擊:http://www.trans1.cn
 
關(guān)鍵詞: Heavy metals
[ 網(wǎng)刊訂閱 ]  [ 專業(yè)英語搜索 ]  [ ]  [ 告訴好友 ]  [ 打印本文 ]  [ 關(guān)閉窗口 ] [ 返回頂部 ]
分享:

 

 
推薦圖文
推薦專業(yè)英語
點(diǎn)擊排行
 
 
Processed in 0.174 second(s), 17 queries, Memory 0.9 M
主站蜘蛛池模板: 国产美女一级ba大片免色 | 手机看片国产免费 | 欧美黄色影院 | 欧美性野久久久久久久久 | 好吊色视频988gao在线观看 | 黑人性xx | 日本高清网站 | 免费人成在线观看网站品爱网日本 | 丁香六月婷婷激情 | 五月激情六月 | 亚洲国产精品婷婷久久久久 | 午夜网站免费版在线观看 | 高h细节肉爽文bl1v1 | 亚洲影视一区二区 | 中文字幕婷婷 | 在线精品国产第一页 | 亚洲午夜久久影院 | 久久久久久国产精品免费免费 | 小草影院亚洲私人影院 | 国产精品久久久久久久久久免费 | 天天澡天天摸天天添视频 | 在线观看色视频 | 久久噜噜噜久久亚洲va久 | 男男gay污小黄文 | 国产女人和拘做受视频免费 | 日韩一级视频免费观看 | 永久免费人成网ww555kkk手机 | 精品欧美一区二区三区在线观看 | 国产亚洲人成网站观看 | 天天摸日日摸人人看 | 欧美日韩一区二区三区毛片 | 一级一黄在线观看视频免费 | 天堂视频在线免费观看 | 轻点灬大ji巴太粗太大了小说 | 1024毛片基地 | 澳门久久精品 | 欧美在线天堂 | 成人午夜精品久久久久久久小说 | 美女黄色毛片 | 色综合久久一区二区三区 | 亚洲日本在线观看 |