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环境毒理学研究的其研究内容和任务有哪些?

答案

参考答案:

环境毒理学在环境因素对健康影响研究中的作用是十分重要的,它的研究内容和任务主要是:

(1)环境污染物(毒物)接触机体后的吸收、分布、代谢和排泄过程。

(2)污染物的毒作用大小、蓄积性、作用的靶器官和组织等基本毒理学特征。

(3)污染物毒作用的机制及在机体内产生的主要生物学效应。

(4)污染物的特殊毒作用(致畸、致癌、致突变性)检测和评价。

(5)研究和探索污染物在机体反应中出现的特异、敏感的测试指标,即生物标志,为环境流行病学调查提供新的手段。

(6)对已造成健康危害,并通过环境流行病学调查提出的可疑致病因素,建立动物模型予以证实。

(7)对于新合成的化合物或即将进入环境的化学物(化工产品、污染物、农药等)的毒理学安全性评价。

(8)应用于环境生物监测。

阅读理解

Bissel is a small village of the West Sahara. It lies next to a l.5-square-kilometer oasis(绿洲), from where three days and nights are generally required to go out of the desert. However, before Ken Levin discovered it in 1926, none of the Bissel villagers had ever walked out of the desert. Reportedly, they were not unwilling to leave this barren land. Many had previously tried but failed, always somehow finding themselves back at the oasis after several days of trying to walk out.

When interviewed by Ken Levin, an expert at the British Royal College of Sciences, the villagers explained that no matter which direction they walked it always brought them back to the village.Why couldn’t the Bissel villagers walk out of the desert? Levin was very puzzled. He had, by himself, managed to walk north from the village and reach the nearest town in three and a half days. He decided to carry out an experiment to solve the mystery. He and a Bissel villager called Argutel, would walk out of the desert together. They prepared enough water for a half-a-month journey and two camels. But this time Ken Levin didn't bring his compass. Levin would follow Argutel.

Ten days later, they had walked for about 500 miles but were still in the desert. On the 11th morning, an oasis came into their view. They were back at Bissel. Levin now understood why the Bissel people couldn’t escape the desert. They had no knowledge of the North Star, which had for centuries provided sailors and other travelers with a point of direction. In the desert, if a person goes forward relying only on their senses, they will not be able to travel in a straight line. Rather they will travel in a very large circle and eventually track back to where they began. Levin explained to Argutel the function of the North Star and said, “As long as you rest in the daytime and walk towards the brightest star at night, you would be able to walk out of the desert.” Argutel did as he was told. Three days later, he came to the edge of the desert.

Now in the West Sahara, Bissel has become a bright pearl, where tens of thousands of tourists come every year. Argutel’s bronze statue stands in the center of the town. On its base are the words: __________________________________.

小题1:Ken Levin asked Argutel to walk to the north in order to ________.

A.prove that people could walk out of the desert see

B.how far away Bissel was to the edge of the desert

C.tell people not to walk in circles

D.show Argutel was a great person小题2:According to the passage, Ken Levin ________.

A.knew Argutel before he came to the village

B.came to Bissel to do experiments on behalf of his college

C.became the first man to walk out of the desert from Bissel Village

D.taught Bissel villagers knowledge of the North Star when he first arrived小题3:It can be inferred from the passage that ________.

A.Ken Levin didn’t walk south because it would take more days

B.the use of a compass was necessary to walk out of the desert

C.tourism in Bissel has been greatly developed and improved

D.Argutel became the leader of Bissel after his return小题4:Which of the following can most probably be found at the base of Argutel’s statue?

A.A new life starts from the fixed direction.

B.Where there is a will, there is a way.

C.A long journey starts with the first step.

D.Two heads are better than one.

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