The Grand Canyon has several weather environments. The top is often much different from the bottom. On some winter days, for example, you may find cold winds and snow at the top. But at the bottom, you may find warm winds and flowers. Could your cellphone give you cancer? Whether it could or not, some people are worrying about the possibility that phones, powerlines and wi-fi (路由器) could be responsible for a range of illnesses, from rashes to brain tumours.
For example, Camilla Rees, 48, a former investment banker in the US, moved out of her apartment in San Francisco because of the radiation coming from next door. Rees told the Los Angeles Times that when her neighbors moved in and installed a wi-fi router she lost her ability to think clearly. “I would wake up dizzy in the morning. I’d fall to the floor. I had to leave to escape that nightmare,” she said. Since then, she’s been on a campaign against low-level electromagnetic fields, or EMFs（低频电磁场）.
And she’s not alone. Millions of people say they suffer from headaches, depression, nausea and rashes when they’re too close to cellphones or other sources of EMFs.
Although the World Health Organization has officially declared that EMFs seem to pose little threat, governments are still concerned. In fact, last April, the European Parliament called for countries to take steps to reduce exposure to EMFs. The city of San Francisco and the state of Maine are currently considering requiring cancer-warning labels on cellphones.
If these fears are reasonable, then perhaps we should all be worried about the amount of time we spend talking on our phones or plugging into wi-fi hotpots.
Some say there is evidence to support the growing anxieties. David Carpenter, a professor of environmental health sciences at the University at Albany, in New York, thinks there’s a greater than 95% chance that power lines can cause childhood leukemia. Also there’s a greater than 90% chance that cellphones can cause brain tumours.
But others believe these concerns are unreasonable paranoia (猜疑). Dr Martha Linet, the head of radiation epidemiology at the US National Cancer Institute, has looked at the same research as Carpenter but has reached a different conclusion. “I don’t support warning labels for cellphones,” said Linet. “We don't have the evidence that there’s much danger.”
Studies so far suggest a weak connection between EMFs and illness — so weak that it might not exist at all. A multinational investigation of cellphones and brain cancer, in 13 countries outside the US, has been underway for several years. It’s funded in part by the European Union, in part by a cellphone industry group.
According to Robert Park, a professor of physics at the University of Maryland in the US, the magnetic waves aren’t nearly powerful enough to break apart DNA, which is how known threats, such as UV rays and X-rays, cause cancer.
Perhaps it’s just psychological. Some experts find that the electro-sensitivity syndrome seems to be similar to chemical sensitivity syndrome, which is a condition that’s considered to be psychological.
Whether EMFs are harmful or not, a break in the countryside, without the cellphone, would probably be good for all of us.
| Title: Could cellphones give you cancer? | |
| Key points | Supporting details |
| Cellphones are (71)______ to use | ● Some people think it (72)______ for cellphones to cause cancer. ● Camilla Rees got ill after his neighbor installed a wi-fi router. ● Millions of people have the (73) _______ problems as Camilla. ● Some evidence supports people’s anxieties. |
| Cellphones are safe to use
| ● Some believe that these concerns are just paranoia. ● So far, studies show that there isn’t much (74)______ between EMFs and illness. ● Robert Park thinks that the magnetic waves aren’t powerful enough to （75)_______ DNA. ● It’s just for psychological (76)_______ that people feel ill when they use cellphones. |
| Attitudes and (77)______ | ● Some governments are (78)_______ about the safety of cellphones or EMFs. ● The author thinks that we should（79)_______ the chance of talking on the phone or spend more time in the（80)_____ areas without cellphones. |
She was right to feel a sense of urgency. Bamboo forests are being rapidly used up, and a United Nations report showed that even though bamboo is highly renewable, as many as half of the world’s species are threatened with dying out. Heinricher knew that bamboo could make a significant impact on carbon emissions (排放) and world economies, but only if huge numbers could be produced. And that’s just what she and Burr figured out after nine years of experiments—a way to grow millions of plants. By placing cuttings in test tubes with salts, vitamins, plant hormones, and seaweed gel, they got the plants to grow and then raised them in soil in greenhouses.
Waste to Energy—JUST BURN IT!
WHY BURN WASTE?
Waste-to-energy plants generate (产生) enough electricity to supply 2.4 million households in the US. But, providing electricity is not the major advantage of waste-to-energy plants. In fact, it costs more to generate electricity at a waste-to-energy plant than it does at a coal, nuclear, or hydropower plant.
The major advantage of burning waste is that it considerably reduces the amount of trash going to landfills. The average American produces more than 1,600 pounds of waste a year. If all this waste were landfilled, it would take more than two cubic yards of landfill space. That’s the volume of a box three feet long, three feet wide, and six feet high. If that waste were burned, the ashes would fit into a box three feet long, three feet wide, but only nine inches high!
Some communities in the Northeast may be running out of land for new landfills. And, since most people don’t want landfills in their backyards, it has become more difficult to obtain permits to build new landfills. Taking the country as a whole, the United States has plenty of open space, of course, but it is expensive to transport garbage a long distance to put it into a landfill.
TO BURN OR NOT TO BURN?
Some people are concerned that burning garbage may harm the environment. Like coal plants, waste-to-energy plants produce air pollution when the fuel is burned to produce steam or electricity. Burning garbage releases the chemicals and substances found in the waste. Some chemicals can be a threat to people, the environment, or both, if they are not properly controlled.
Some critics of waste-to-energy plants are afraid that burning waste will hamper (妨碍，阻碍) recycling programs. If everyone sends their trash to a waste-to-energy plant, they say, there will be little motive to recycle. Several states have considered or are considering banning waste-to-energy plants unless recycling programs are in place. Massachusetts, New Jersey, and New York City have delayed new waste-to-energy plants, hoping to increase the level of recycling first.
So, what’s the real story? Can recycling and burning waste coexist? At first glance, recycling and waste-to-energy seem to be at odds (不一致), but they can actually complement (弥补) each other. That’s because it makes good sense to recycle some materials, and better sense to burn others.
Let’s look at aluminum, for example. Aluminum mineral is so expensive to mine that recycling aluminum more than pays for itself. Burning it produces no energy. So clearly, aluminum is valuable to recycle and not useful to burn.
Paper, on the other hand, can either be burned or recycled—it all depends on the price the used paper will bring.
Plastics are another matter. Because plastics are made from petroleum and natural gas, they are excellent sources of energy for waste-to-energy plants. This is especially true since plastics are not as easy to recycle as steel, aluminum, or paper. Plastics almost always have to be hand sorted and making a product from recycled plastics may cost more than making it from new materials.
To burn or not to burn is not really the question. We should use both recycling and waste-to-energy as alternatives to landfilling.
Waste to Energy—JUST BURN IT!
| WHY BURN WASTE? | Advantages of waste to Energy | ◆Though at a high (71) _______, waste-to-energy plants can produce enough electricity for 2.4 million US households. ◆Burning waste can (72) _______ a considerable amount of trash going to landfills. |
| (73)_______ for landfilling | ◆Some communities (74) _______ land for new landfills. ◆Most people refuse to build landfills around. ◆Building landfills in far-away areas will increase the cost of (75) _______ garbage. | |
| TO BURN OR NOT TO BURN? | (76) __________ about burning garbage | ◆Burning garbage releases chemicals, which, if not properly controlled, can be (77) _______ to people and the environment. ◆Burning garbage will hamper recycling programs. |
| Coexistence of recycling and burning waste | Recycling and waste-to-energy can go well with each other in that some materials like aluminum are fit to recycle, while others like plastics are fit to (78) _______. | |
| (79)__________ | Whether to burn or not to burn, we should (80) _______ landfilling with both recycling and waste-to-energy to deal with garbage. | |