2 . A study of almost 2,700 children aged between seven and ten in 38 schools in Barcelona, Spain, first researches the impact of traffic noise on child cognitive development over time.

The children in the study are in a critical stage for the development of memory and attention skills, which are essential to learning. The research found that children exposed to about three times more traffic in the street than other children had memory development that was 23% slower and attention ability development 5% slower over a year.

Noise is the second most damaging environmental factor to health, after air pollution, and, for example, was already known to increase heart attacks in adults. The UN said that urban noise pollution was growing into a global public health threat, leading to 12,000 early deaths a year in the EU alone and affecting many cities.

But research on the impact of road noise on children was limited until now. “We do not understand that noise can actually be toxic (有害的) from a physical point of view,” said Dr. Maria Foraster, from the Barcelona Institute for Global Health, who led the study. “We think that we adapt to it, but research has shown that we don’t completely — we still have a physiological (生理的) response.”

The research revealed that peaks of noise heard inside the classroom, such as the passing of loud trucks, had more impact than a higher average level of noise. It also found higher noise levels at school were more damaging than at home.

Prof. Iroise Dumontheil, at Birkbeck, University of London, UK, said, “This carefully designed study provides convincing evidence. Considering that many European children living in large cities are exposed to high road-traffic noise levels, this study has implications for public policy to reduce road-traffic noise near schools.”

The research follows previous work that showed higher levels of aircraft noise at school affected reading comprehension and cognitive development. Next, the authors said, they would like to see their findings replicated (复制) in different cities and towns, where schools may be built differently and windows opened more or less often.

4 . In 1907, Leo Baekeland invented Bakelite — the first ever plastic. Since then, plastics have been used widely in various industries and people’s lives. Plastic bags were introduced to supermarkets in 1977. Now, 160,000 plastic bags are used globally every second!

    1     However, they are extremely inconvenient for the earth:

 Plastic bags live on much, much longer — perhaps as much as 1,000 years in a landfill (垃圾填埋地).

 When plastic breaks down in the ocean, it doesn’t break down completely.     2     The toxic (有毒的) chemicals from the plastic waste then enter the food chain.

 Plastic bags cause the death of many sea animals when they are mistaken for food. In 2008, a whale was found beached in California. It died due to the more than 22 kilos of plastic found in its stomach.

    3     However, sometimes you get to the store and realize you left your reusable shopping bag at home.

The key to improving our environmental behavior is to make a plan. And you should build your environmental muscle memory: Put your recyclable bags somewhere that will ensure you always remember to bring them with you.

If you drive to the store, keep your bags in your car.     4     If you walk, store your reusable bags near your front door.

Through this act of green, you have created a plan to ensure you will always have your reusable grocery bags on hand when you need them.     5     So build a plan and keep to it!

5 . Flower scents (香味) help pollinators (传粉者) locate their favorite plants. Scientists have established that air pollutants change those scents, throwing off the tracking abilities of such beneficial insects as honeybees. But new lab experiments are the first to confirm that one pollinator, the tobacco hawkmoth, can quickly learn that a pollution-changed scent comes from the jasmine tobacco flower that the insect likes.

Chemical ecologist Markus Knaden and colleagues focused on one pollutant-ozone, the main element in smog. In the lab, his team blew an ozone-changed scent from a tiny tube into a tunnel, with a moth (飞蛾) awaiting at the far end of the tunnel. Usually, when the moth smells the unchanged scent, it flies upwind and uses its long, skinny mouthparts to probe the tube the way that it would a flower. The researchers expected that the changed scent might throw the moth off a little. But the insect wasn’t attracted at all.

In addition to scent, tobacco hawkmoths track flowers visually, so Knaden’s team used the feature, along with a sweet snack, to train the moth to be attracted to a pollution-changed scent. The researchers wrapped a brightly-colored artificial flower around the tube to trick the moth back across the tunnel, despite the unfamiliar scent. And the team added sugar water to the artificial flower. After a moth was given four minutes to taste the sweet stuff, it was attracted to the new smell when sent into the tunnel 15 minutes later, even when neither the sugar water nor the visual signal of the artificial flower was present.

This study focused on only one moth species, but Knaden’s team is now working on planning experiments with other pollinators that are easier to follow than tobacco hawknoths. While he guesses honeybees might also be as adaptable as the moth was, that won’t be true of every pollinator. “The situation can become very bad for insects that are not as clever or cannot see that well. I don’t want the take-home message to be that pollution is not a problem.”

8 . Noise pollution has a long-term effect on tree populations that may persist even after the sources of noise are removed, according to research published Wednesday.

Man-made noise from industry and the building of infrastructure such as roads and pipelines has increased greatly since the middle of last century. While previous research has documented the short-term effect noise has on tree populations as it scares off pollinators (传粉者) such as insects and animals, few studies have covered the long-term effect.

Researchers in the United States looked at tree populations in New Mexico that had been “hearing”a high level of man-made noise for 15 years. They found 75 percent fewer pinyon pine seedlings (矮松苗) in noisy places than quiet ones.

Then they looked at other places in New Mexico, where sources of noise had recently been added and then removed, and examined how populations recovered. The team assumed that populations of the trees — in this case pinyon seedlings — would recover as the pollinators would return to the places once the noise had disappeared. Instead, they found a long-term drop in seedling numbers as the birds refused to revisit the places.

“The effects of human noise pollution are growing into these woodland communities,” said Clinton Francis, lead researcher from California Polytechnic State University. “What we’re seeing is that removal of the noise doesn’t necessarily immediately result in a recovery of ecological function.”

Jennifer Phillips, co-author of the research, said the findings showed how the effect of noise pollution could put pollinators off even after the noise is removed. “Animals like the birds that are sensitive to noise learn to avoid particular areas.” said Phillips. “It may take time for animals to come back to pollinate trees in these previously noisy areas, and we don’t know how long that might take.”

As governments continue to face growing evidence of the damage to nature caused by urbanization (城市化), Phillips held that the influence of noise pollution should also be factored into planning decisions.

9 . The effects of noise can reach organisms (生物体) without ears. Because of the way living things rely on each other, noise pollution may actually stop some forests from growing, a new study suggests. In a New Mexico woodland of pine trees, researchers found far fewer tree seedlings (小苗) in noisy sites than they did in quiet ones.

The study area is dotted with gas wells, some of which are quiet and some of which have compressors (压缩机) that create a constant noise. This allowed Jennifer Phillips, a behavioral ecologist at Texas A&M University-San Antonio and her colleagues to compare sites that were similar except for noise level. In areas that had been noisy for at least 15 years, the researchers found only about 13 pine seedlings, compared with 55 pine seedlings per hectare (公顷) in quiet areas.

The differences in plant growth were probably caused by changes in animal behavior, said Phillips. For example, noise might drive away certain pollinators (传粉昆虫) such as bees, bats and moths. In the case of pine trees, the problem was likely a lack of animals to disperse seeds. Pines depend on birds to carry their seeds away from the parent tree, and birds are known to avoid noise. The differences between the sites aren’t yet obvious to someone walking through them, said Sarah Termondt, a botanist (植物学家) with the U.S. Fish and Wildlife Service who helped conduct the study. That’s probably because pines are slow-growing, with most of the mature trees in such woodlands being over a century old.

The study raises questions about the future of the area. “If the noise stays there long term, are we going to lose this important ecosystem of the pine which supports so much wildlife?” said Phillips. The study was published today in the journal Proceedings of the Royal Society.