1 . There is an increasing alarm about the extent of microplastics pollution, which has been found everywhere from Everest to the Arctic. However, it turns out there’s an even smaller and more poisonous form of plastic pollution entering remote reaches of the globe. A new study published in Environmental Research found significant quantities of nanoplastics (纳米塑料) in ice samples from both the North and South Poles.
“Now we know that nanoplastics are transported to these corners of the Earth in these quantities. This indicates that nanoplastics are really a bigger pollution problem than we thought,” study lead author Dusan Materic said in a press release.
Nanoplastics are plastics that are smaller than a micrometer in size. Their small size means they are more difficult to study than microplastics, or plastics between five millimeters and a micrometer. But they may be even more dangerous.
“Nanoplastics are very toxicological active compared to, for instance, microplastics, and that’s why this is very important,” Materic said.
Materic and his team used new methods to measure nanoplastic pollution in ice samples from Greenland and Antarctica. They sampled a 14-meter-deep ice core from the Greenland ice cap and sea ice from Antarctica’s McMurdo Sound. They found that there were an average of 13.2 nanograms per-milliliter of nanoplastics in the Greenland ice and an average of 52.3 nanograms per milliliter in the Antarctic ice
But what was even more surprising than the amount of nanoplastics in the remote ice was just how long they had sat there. “In the Greenland core, we see nanoplastic pollution happening all the way from the 1960s. So organisms, despite the lack of the solid evidence, likely all over the world, have been exposed to it for quite some time now,” Materic said.
The study also looked at the types of plastic present in the samples. Half of the Greenland nanoplastics were polyethylene (PE), the kind of plastic used for plastic bags and packaging. A quarter came from tires and a fifth were polyethylene terephthalate (PET), which is used for clothing and bottles.
1. Why should researchers focus more on nanoplastics?| A．They are smaller but more dangerous. |
| B．They are more important to science. |
| C．They are easily polluted by ocean water. |
| D．They are more active in cold surroundings. |
| A．The North and South poles are the birthplace of nanoplastics. |
| B．Nanoplastics have less influence on the planet than microplastics. |
| C．Nanoplastics have been existing since the 1960s throughout the world. |
| D．Nanoplastics found in the samples are widely used in the daily life. |
| A．The Greenland core. |
| B．The Antarctic ice. |
| C．The amount of nanoplastics. |
| D．Nanoplastics pollution. |
| A．Mircoplastics prove to be more dangerous. |
| B．Nanoplastics pose a threat to people’s life. |
| C．Nanoplastics are making their way to the poles. |
| D．Mircoplastics set the alarm bells ringing. |
2 . Microplastics, as the name implies, are tiny plastic particles found in the environment. Any plastic particle that has a diameter of less than 5 mm is considered to be microplastic. For a long time, a majority of people were unaware of the presence of microplastics and their effects on the environment. However, these particles have become a significant topic of debate in recent times after researchers noted their presence in almost every corner of the globe. from Mount Everest to the Mariana Trench.
There are two categories of microplastics: primary and secondary. Primary microplastics are tiny particles meant for external commercial use such as cosmetics, as well as microfibers to make other textiles, such as fishing nets. Secondary microplastics are particles that result from the breakdown of larger plastic items, such as water bottles.
There are various sources of microplastics. Wastewater treatment plants and sewage treatment plants are the major sources of primary microplastics, most of which are residues (残留物) of cosmetics, paint, household and industrial waste. Single-use plastics plastic items meant to be used just once and then discarded, such as a straw — are the main source of secondary plastics in the environment.
The problem with microplastics is that like plastic items of any size they do not readily break down into harmless molecules. Plastics can take hundreds or thousands of years to decompose (降解). That means once produced, we cannot get rid of them. Microplastics exist on beaches and deeper waters, and have been detected in marine organisms from plankton to whales, in commercial seafood, and even in drinking water. They are mistaken for food by marine animals and some plastics are so tiny that they end up in the animal tissues. They are passed across the food chain, and some find their way to humans.
Scientists are still unsure whether consumed microplastics are harmful to human or animal health and if so, what specific dangers they may pose. Even so, many countries are taking action to reduce microplastics in the environment. The best approaches to controlling microplastics include proper handling of plastics and thorough treatment of wastewater.
1. According to the first two paragraphs, microplastics are_________| A．common in our daily life |
| B．used to make glass bottles |
| C．found in all the uninhabited areas |
| D．tiny plastic particles with a diameter of 5mm |
| A．The use of straws should be forbidden. |
| B．Household waste contains microplastics. |
| C．Industrial waste is a source of secondary plastics |
| D．Wastewater and sewage treatment plants are useless. |
| A．Because they’re consumed as food. |
| B．Because they exist on the beaches. |
| C．Because they easily break down. |
| D．Because they’re left out in the food chain. |
| A．To analyze the sources of microplastics. |
| B．To warn people of the danger of microplastics. |
| C．To give an overall introduction to microplastics. |
| D．To persuade people to give up the use of microplastics. |
3 . 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.”
1. What does the underlined word “impeded” in the first paragraph mean?| A．separated. | B．disabled. | C．demanded. | D．protected. |
| A．Poorer human health. | B．Fewer wildlife species. |
| C．More delicate biological systems. | D．Less nightly culture elements of the sky. |
| A．Crowd sourced data are invaluable | B．Shorter wavelengths are hard to detect. |
| C．Satellites play a vital role. | D．White LEDs are widely used. |
| A．Their consistent efforts pay off. | B．The dataset needs to be updated. |
| C．The sky glow has been over-emphasized. | D．More participants are expected to join in. |
