Read the following passage and answer the questions that follow:
Every urbanite knows that the bright lights of the city make it impossible to see all the stars in a night sky. What most of us don’t know is that those lights might also be making us sick. The cause is light pollution- the unearthly glow of billions of street lamps, security and porch lights, searching, and office lights signs-as people everywhere try to dispel the limitations of the light.
For the first time, light is being investigated seriously as a human health hazard, a possible contributor to the increased rate of breast cancer, depression and other ailments. And for many wildlife species, light pollution seems to be as grave an environmental threat as cleared habitats and toxic-chemical dumping. “People are beginning to take it much more seriously,” says Alan Outen, a British ecologist who has written extensively on the dangers of night brightness. “Its implications are far, bigger than ever realized.”
Nearly two third of the world’s population lives under night skies polluted by light, accordance to the first atlas of the world’s artificial night-sky brightness, published by Italian and US researchers in 2001. In the most heavily urbanized regions, it no longer ever really gets dark. Satellite images
reveal that in large areas of East North America, Western Europe, Japan and South Korea, night has become a constant twilight. Because of the reflective properties of snow, Canadian cities are particularly flooded in light pollution. In a natural night sky, someone looking at the heavens with the unaided eye should be able to see nearly 3500 stars and planets and the glow from the Milky Way, our home galaxy. But in cities like Toronto, the number of visible stars has dwindled to about a few dozen.
This stunning drop has caused Canada’s foremost astronomy writer, Terence Dickinson, to lament, “It’s now possible to grow up never having been exposed to the natural beauty and. inspiration of the night sky.” The key author of the bright-sky atlas, Italian astronomer Pierantonio Cinzano, and his research team have found that many people’s eyes now never get to the stage where they are fully adapted to darkness. The researchers have calculated that one tenth of people in the world, including about 60 per cent of Canadians living in highly populated southern areas, have lost much of their night vision.
Other creatures appear also to be highly susceptible to this disturbance. Lighting from office towers confuses migratory birds, which fly into buildings lit up at night. Millions of birds in North America die from these crashes. In Toronto alone, downtown skyscrapers injure or kill an estimated 24,000 birds a year, according to monitoring by a local environment group.
1.What does every urbanite know?
2. What have Cinzano and his team found ?
3. Which health hazard is caused due to light pollution ?
4. What is the thing that confuses the migratory birds ?
5. What do most of us not know?
