In the past few years, scientists have found microplastics in our soil, tap water, bottled water, beer and even in the air we breathe. And there’s growing concern about the potential health risks they pose     1    humans.

The new analysis in the UK have discovered microplastics widely distributed across all 10 lakes and rivers sampled. More than 1,000 small pieces of plastic per litre were found in the River Tame, which was revealed last year as    2     (pollute) place tested worldwide. Even in relatively remote places such as the Falls of Dochart and Loch Lomond in Scotland, two or three pieces per litre were found.

Microplastics are not a specific kind of plastic, but rather any type of small pieces of plastic    3     is less than 5 mm in length according to the U.S. National Oceanic and Atmospheric Administration. They    4    originate from a variety of sources, including cosmetics, clothing, and industrial processes.

Humans are known to consume the tiny plastic particles through food and water, but the possible health effects on people and ecosystems have yet    5     (determine). One study, in Singapore, has found that microplastics can harbor harmful microbes.

Research by the National University of Singapore found more than 400 types of bacteria on 275 pieces of microplastic    6     (collect) from local beaches.     7     included insects that cause gastroenteritis (肠胃炎) and wound infections in humans.

“Microplastics    8     (find) absolutely everywhere now but we do not know the harm they could be doing,” said Christian Dunn at Bangor University, Wales, who led the work. “It’s no use    9     (look) back in 20 years’ time and saying: ‘If only we’d realized just how bad it was.’ We need to be monitoring our waters now and we need to think, as a country and a world,     10     we can be reducing our reliance on plastic.”

4 . A new analysis of photographs from the International Space Station has identified a shift in the kind of lighting technologies that European countries are using at night to brighten streets and buildings. Researchers have found that the old warm high-pressure street lights are rapidly being replaced by cooler LED lights. The University of Exeter study, published in Science Advances, claimed that “this phenomenon is widely increasing the risk of harmful effects to ecosystems”.

LED lighting was promoted as being intended to reduce emissions, but its usage has raised energy consumption. One explanation of this is that the increase in power efficiency and the associated decrease in economic cost have driven increased demand for lighting, therefore, any efficiency gains have been counteracted by increased consumption of light.

The study also claimed that previous research into the effects of light pollution have underestimated the impacts of blue light radiation. Chief among the health consequences of blue light is its ability to reduce the production of melatonin(褪黑素)that regulates sleep patterns in humans and other organisms. Scientific studies have warned that increased exposure to artificial blue light can worsen people’s sleeping habits.

The increase in blue light radiation in Europe has also reduced the visibility of stars in the night sky, which may have impacts on people’s sense of nature. Blue light can also alter the behavioral patterns of animals including bats and moths, as it can change their movements towards or away from light sources.

David Smith, of the conservation charity Buglife, said, “Light pollution can dramatically impact animals. We should consider light from a wider biological perspective than that of just humans and focus on better quality lighting that is harmonious with our natural world. Better quality and lower levels of lighting would help save energy, and lower financial costs, while also making our environment safer for living beings. Authorities can dim the lights during night hours, and change the bandwidths(带宽值)of their LED bulbs to produce less harmful blue light.”

5 . Cotton bags have become a means for brands, retailers and supermarkets to convey a planet-friendly mindset — or, at least, to show that the companies are aware of the overuse of plastic in packaging.

Earth-friendly? Not exactly. It turns out the wholehearted embrace of cotton bags may actually have created a new problem. An organic cotton bag needs to be used 20,000 times to make up for its overall impact of production, according to a 2018 study by the Ministry of Environment and Food of Denmark. That is equal to daily use for 54 years — for just one bag. The production of cotton bags is water-intensive, and figuring out how to deal with a bag in an environmentally low-impact way is not nearly as simple as people think, according to Travis Wagner, an environmental science professor at the University of Maine.

In sharp comparison with the frequent use of cotton bags, the disposal (处理) of the bags remains less satisfying. Only 15 percent of the 30 million tons of cotton bags produced every year actually is sent to be recycled. Even when a bag does make it to a treatment facility, most dyes (染料) used to print logos onto them are PVC-based and thus not recyclable; “they’re extremely difficult to disintegrate (分解) chemically,” said Christopher Stanev, the co-founder of Evrnu, a Seattle-based textile recycling firm. Printed patterns have to be cut out of the cloth; Mr. Stanev estimates 10 to 15 percent of the cotton Evrnu receives is wasted this way.

That’s not to say cotton is worse than plastic, or that the two should even be compared. While cotton can use pesticides and has dried up rivers from water consumption, lightweight plastic bags use greenhouse gas-emitting fossil fuels and will fill up the oceans.

Buffy Reid, of the knitwear label & Daughter, stopped production of her cotton bags in April this year. Aesop is converting the composition of its shopping bags to a 60 — 40 blend of recycled and organic cotton. Designer Ally Capellino recently employed a new material, while Hindmarch introduced a new version of her original cotton bag, this time made from recycled water bottles.

In the end, the simplest solution may be the most obvious. “Not every product needs a bag,” Comey says.

9 . If humans were truly at home under the light of the moon and stars, we would go in darkness happily, the midnight world as visible to us as it is to the vast number of nocturnal (夜间活动的) species on this planet. Instead, we are diurnal creatures, with eyes adapted to living in the sun’s light. This is a basic evolutionary fact, even though most of us don’t think of ourselves as diurnal beings. Yet it’s the only way to explain                    what we’ve done to the night: We’ve engineered it to receive us by filling it with light.

The benefits of this kind of engineering come with consequences -- called light pollution -- whose effects scientists are only now beginning to study. Light pollution is largely the result of bad lighting design, which allows artificial light to shine outward and upward into the sky. Ill-designed lighting washes out the darkness of night and completely changes the light levels -- and light rhythms -- to which many forms of life, including ourselves, have adapted. Wherever human light spills into the natural world, some aspect of life is affected.

In most cities the sky looks as though it has been emptied of stars, leaving behind a vacant haze (霾) that mirrors our fear of the dark. We’ve grown so used to this orange haze that the original glory of an unlit night -- dark enough for the planet Venus to throw shadows on Earth -- is wholly beyond our experience, beyond memory almost.

We’ve lit up the night as if it were an unoccupied country, when nothing could be further from the truth. Among mammals alone, the number of nocturnal species is astonishing. Light is a powerful biological force, and on many species it acts as a magnet (磁铁). The effect is so powerful that scientists speak of songbirds and seabirds being “captured” by searchlights on land or by the light from gas flares on marine oil platforms. Migrating at night, birds tend to collide with brightly lit tall buildings.

Frogs living near brightly lit highways suffer nocturnal light levels that are as much as a million times brighter than normal, throwing nearly every aspect of their behavior out of joint, including their nighttime breeding choruses. Humans are no less trapped by light pollution than the frogs. Like most other creatures, we do need darkness. Darkness is as essential to our biological welfare, to our internal clockwork, as light itself.

Living in a glare of our own making, we have cut ourselves off from our evolutionary and cultural heritage-the light of the stars and the rhythms of day and night. In a very real sense, light pollution causes us to lose sight of our true place in the universe, to forget the scale of our being, which is best measured against the dimensions of a deep night with the Milky Way -- the edge of our galaxy -- arching overhead.

10 . Taking in dirty air does great harm to our health. Air pollution lowers the average life spans by a year worldwide and in more polluted parts of Asia and Africa, dirty air shortens lives up to twice that much. Scientists shared their new findings in Environmental Science & Technology Letters. The study used data gathered in 2016 as part of a project known as the Global Burden of Disease and was the first major country-by-country look at the connection between the length of life and what’s known as fine PM.

Air pollution has been linked to many health problems. Most earlier studies had looked at how tiny air pollutants affected rates of illness or death. Joshua Apte is an environmental scientist at the University of Texas at Austin. By looking at life expectancy (预期寿命), his team had hoped to make the threat easier to understand. PM2.5 is what scientists call tiny particles (颗粒) of pollution in the air. Higher levels of PM2.5 can cause health problems and cut months, if not years, from the average length of life. This analysis shows how pollution affects life expectancy in different parts of the world.

The World Health Organization (WHO) recommends limiting PM2.5 to 10 micrograms per cubic meter of air. Apte’s group calculated how holding pollution to this low level would help people. In countries with very dirty air, meeting this standard would lengthen people’s lives. However, in countries whose air already meets this standard, the study shows no gain in life expectancy. In other words, meeting the WHO standard won’t reduce health costs resulting from dirty air because even below 10 micrograms per cubic meter, pollution still causes serious risks. Meanwhile, the scientists compared how other threats including smoking and cancer shorten the length of life across the globe.