埼玉医科大学英語2012年第6問
From plastic bags to pesticides, most of the ( 46 ) we produce on land eventually reaches the oceans, either through deliberate dumping or from runoff through drains and rivers. This includes oil, fertilizers, solid garbage, sewage, and toxic chemicals.
Oil spills cause huge damage to marine environment, but in fact are responsible for only around 12% of the oil entering the seas each year. According to a study by the U.S. National Research Council, 36% comes down drains and rivers as waste and runoff from cities and industries.
Fertilizer runoff from farms and lawns is a huge problem for coastal areas. The extra nutrients cause eutrophication or flourishing of algal blooms that use up the water's dissolved oxygen and suffocate other marine life. Eutrophication has created enormous dead zones in several parts of the world, including the Gulf of Mexico and the Baltic Sea.
Solid garbage also makes its way to the ocean. If plastic bags, balloons, glass bottles, shoes, and packaging material are not correctly disposed of, almost everything we throw away can reach the sea. Plastic garbage, which decomposes very slowly, is often mistaken for food by marine animals. High concentrations of plastic material, particularly plastic bags, have been found ( 47 ) the breathing passages and stomachs of many marine species, including whales, dolphins, seals, puffins, and turtles. Plastic six-pack rings for drink bottles can also choke marine animals. This garbage can also come back to shore, where it pollutes beaches and other coastal habitats.
In many parts of the world, sewage flows untreated into the ocean. For example, 80% of urban sewage discharged into the Mediterranean Sea is untreated. This sewage can also lead to eutrophication. In addition, it can cause human disease and lead to beach closures.
Almost every marine organism, from the tiniest plankton to whales and polar bears, is contaminated with man-made chemicals, such as pesticides and chemicals used in common consumer products. Some of these chemicals enter the sea through dumping. For centuries, the oceans have been a convenient dumping ground for waste generated on land. This continued until the 1970's, with dumping at sea being the accepted practice for disposal of nearly everything, including toxic material such as pesticides, chemical weapons, and radioactive waste.
Dumping of the most toxic materials was banned by the London Dumping Convention in 1972, and an amended treaty in 1996 (the London Convention) further ( 48 ) what could be dumped at sea. However, there are still the problems of already-dumped toxic material, and even the disposal of permitted substances at sea can be a substantial environmental hazard.
Chemicals also ( 49 ) the sea from land-based activities. Chemicals can escape into water, soil, and air during their manufacture, use, or disposal, as well as from accidental leaks or fires in products containing these chemicals. Once in the environment, they can travel for long distances in air and water, including ocean currents.
People once assumed that the ocean was so large that all pollutants would be diluted and dispersed to safe levels. But in reality, they have not disappeared, and some toxic man-made chemicals have even become more concentrated as they have entered the food chain.
Tiny animals at the bottom of the food chain, such as plankton in the oceans, absorb the chemicals as they feed. Because they do not break down easily, the chemicals accumulate in these organisms, becoming much more concentrated in their bodies than in the surrounding ( 50 ) or soil. These organisms are eaten by small animals, and the concentration rises again. These animals are in turn eaten by larger animals, which can travel large distances with their even further increased chemical load.
Animals higher up the food chain, such as seals, can have contamination levels millions of times higher than the water in which they live. And polar bears, which feed on seals, can have contamination levels up to 3 billion times higher than their environment. People become contaminated either directly from household products or by eating contaminated seafood and animal fats. Evidence is mounting that a number of man-made chemicals can cause serious health problems, including cancer, damage to the immune system, behavioral problems, and reduced fertility.
(-http://wwf.panda.org/about_our_earth/blue_planet/problems/pollution)- 問46.( 46 )
- (1) food
- (2) waste
- (3) goods
- (4) things
- 問47.( 47 )
- (1) blocking
- (2) passing
- (3) producing
- (4) releasing
- 問48.( 48 )
- (1) restricted
- (2) reproducing
- (3) relapsed
- (4) reworked
- 問49.( 49 )
- (1) exit
- (2) approach
- (3) avoid
- (4) enter
- 問50.( 50 )
- (1) food
- (2) water
- (3) farms
- (4) plants
- 問51. Where do most ocean oil pollutants come from?( 51 )
- (1) They come from oil spills and industrial dumping.
- (2) They come from rivers, being carried as runoff.
- (3) They come from cities and factories on coast areas.
- (4) They come from untreated sites near the oceans.
- 問52. Which of the following is NOT a problem for ocean life?( 52 )
- (1) An increase in ocean plant life being caused by fertilizer runoff.
- (2) A concentration of contaminants being passed through the food chain.
- (3) An increase in human cancer cases due to pollutants in seafood.
- (4) Various sea animals eating plastics that look like food.
- 問53. What could be the most likely outcome if pollution is not reduced in our oceans?( 53 )
- (1) Small plankton will increase in number.
- (2) Plastics will not be allowed on restricted beaches.
- (3) More and more marine life will suffer from contamination.
- (4) Toxic chemicals may enter our farms and food supplies.
- 問54. What happens to the chemicals in the ocean?( 54 )
- (1) They are diluted and dispersed to safe levels because the ocean is very large.
- (2) Some chemicals are eaten by small animals and others can gradually disappear into the water.
- (3) They enter the food chain are absorbed by organisms, and are accumulated in their bodies.
- (4) They can travel large distances with animals, but they disappear.
- 問55. What would be the best title for this article?( 55 )
- (1) Land-based activities and their effects on marine pollution
- (2) Human health at risk because of pollution levels in our seas
- (3) Plastic and pesticides to kill our marine life and close our beaches
- (4) The sources of human-health concerns: polluted seas and life