2 . In the endless sky, the unaided human eye should be able to perceive several thousand stars on a clear, dark night. Unfortunately, growing light pollution has impeded people from the nightly view.

New citizen-science-based research throws alarming light on the problem of “sky glow”-the diffuse illumination (漫射照明) of the night sky that is a form of light pollution. The data came from crowd-sourced observations collected from around the world as part of Globe at Night, a program developed by astronomer Connie Walker.

Light pollution has harmful effects on the practice of astronomy but also on human health and wildlife, since it disturbs the cycle from sunlight to starlight that biological systems have evolved alongside. Furthermore, the loss of visible stars is a great loss of human cultural heritage. Until relatively recently, humans throughout history had an impressive view of the starry night sky, and the effect of this nighty spectacle (壮观) is evident in ancient cultures.

Globe at Night has been gathering data on star visibility since 2006. Anyone can submit observations through the Globe at Night web application. Participants record which one best matches what they can see in the sky without any telescopes or other instruments.

Researchers find that the loss of visible stars indicates an increase in sky brightness of 9.6% per year while roughly 2% is measured by satellites. Existing satellites are not well suited to measuring sky glow as it appears to humans, because they can not detect wavelengths shorter than 500 nanometers (纳米). White LEDs, with shorter wavelengths under 500 nanometers, now are increasingly commonly used in outdoor lighting. But human eyes are more sensitive to these shorter wavelengths at nighttime. Space-based instruments do not measure light from windows, either. But these sources are significant contributors to sky glow us seen from the ground.

“The increase in sky glow over the past decade underlines the importance of redoubling our efforts and developing new strategies to protect dark skies,” said Walker. “The Globe at Night dataset is necessary in our ongoing evaluation of changes in sky glow, and we encourage whoever can to get involved to help protect the starry night sky.”

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.”

7 . 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.”

E-TRASH

Nowadays, every household produces electronic trash (or e-trash)—an old TV or computer, a printer, or an out-of-date cell phone. But when we throw these everyday items away, not many of us know    1    they go. The journalist and photographer, Peter Essick, decided to follow this e-trash    2    several countries around the world.

In particular, Essick found that a lot of e-trash goes to Ghana. There, he saw    3    (mountain) of old computers in the local markets. The sellers resell some of them,    4     not many work. Instead, they recycle the broken computers by melting the parts inside. These parts contain a little metal such as copper or even gold. However, this recycling process is    5    (danger) for the workers because    6    produces a lot of toxic chemicals.

As a result of his journey, Peter Essick thinks it’s important to stop     7    (export) e-trash. It’s bad for the environment and it’s bad for    8    (people) health. Instead, he believes manufacturers need    9     (produce) more eco-friendly electronics, in other words, electronic products that you can recycle cheaply, safely, and in the country where they    10    (make).

9 . 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.