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Geology and Health
1. 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 recognised 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.

2. 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.

3. 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.

4. 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.

5. 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.

6. 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.

Á·Ï°£º
1. Paragraph 1 ______________
2. Paragraph 3 ______________
3. Paragraph 4 ______________
4. Paragraph 6 ______________

A. No evidence to indicate bad effects of naturally contaminated soil
B. Potential hazards of human contaminated soils
C. Research on channels of heavy metals getting into human food chain
D. Geology and health problems
E. Rocks¡ªthe ultimate source of soil pollution
F. Long-term health effects on children

5. Some serious diseases is connected with deficiency of ______________
6. It is extremely necessary to study the long-term effects caused by living on ______________
7. Geologists are indispensable in the research project on geology and health due to their knowledge on ______________
8. Industrially contaminated sites usually require a thorough clean up due to ______________
A. industrially polluted soils

B. rock and soil chemistry
C. naturally polluted soils
D. the pathways of metals into the food chain
E. the element of iodine
F. the persistence of heavy metals
More Rural Research Is Needed
1. Agricultural research funding is vital if the world is to feed itself better than it does now. Dr. Tony Fischer, crop scientist, said demand was growing at 2.5% per year, but with modern technologies and the development of new ones the world should be able to stay ahead.

2. ¡°The global decline in investment in international agricultural research must be reversed if significant progress is to be make towards reducing malnutrition and poverty, ¡± he said.

3. Research is needed to solve food production, land degradation and environmental problems. Secure local food supplies led to economic growth which, in turn slowed population growth. Dr. Fischer painted a picture of the world's ability to feed itself in the first 25 years, when the world's population is expected to rise from 5.8 to 8 billion people. He said that things will probably hold or improve but there'll still be a lot of hungry people. The biggest concentration of poor and hungry people would be in sub-Saharan Africa and southern Asia in 2020, similar to the current pattern. If there is any change, a slight improvement will be seen in southern Asia, but not in sub-Saharan Africa. The major improvement will be in east Asia, South America and South-East Asia.

4. The developing world was investing about 0.5%, or $8 billion a year, of its agricultural gross domestic product (GDP) on research, and the developed world was spending 2.5% of its GDP. Dr Fischer said more was needed from all countries.

5. He said crop research could produce technologies that spread across many countries, such as wheat production research having spin-offs for Mexico, China of India.

6. ¡°Technologies still need to be refined for the local conditions but a lot of the strategic research can have global application, so that money can be used very efficiently,¡± Dr. Fischer said.

7. Yields of rice, wheat and maize have grown impressively in the past 30 years, especially in developing countries. For example, maize production rose from 28 tones per hectare between 1950 and 1995. But technologies driving this growth, such as high-yield varieties, fertilisers and irrigation, were becoming exhausted. ¡°If you want to save the land for non-agricultural activities, for forests and wildlife, you're going to have to increase yield, ¡±Dr Fischer said.

Á·Ï°£º
1. Paragraph 1 ______________
2. Paragraph 3 ______________
3. Paragraph 4 ______________
4. Paragraph 7 ______________

A. The same or improved food supply situation in 2020
B. Research focus on increased yield
C. More research funding needed
D. Local situations analyzed
E. Increase in investment on agricultural research
F. Sustained development of modern technologies

5. Dr. Fischer claims that agriculture will continue to develop ______________.
6. Land can be saved for other purposes ______________.
7. The investment can be regarded as efficient ______________.
8. The global decrease in investment should be changed ______________.

A. if we can drive yield up.
B. when Mexico China and India join in the project.
C. if we want to fight against malnutrition and poverty.
D. when we use modern technologies and develop new ones.
E. when the developed world help the developing world.
F. when strategic research can be utilized worldwide.