1 . Sleeping in a noisy room isn’t only distracting (使人分心的), and it can also harm your health. Although researchers have known for decades that long­term loud noises can harm us, it’s only recently become recognized as a widespread problem.

In a new review of previously published studies, researchers from Germany and Denmark took a look at the ways in which noises, such as an airplane passing by or jackhammer digging in the ground, can affect our hearts. Perhaps the most obvious impact of a loud sound while you are sleeping is that it can wake you up. But, even if you don't remember hearing the noise or you don’t physically get out of bed, it can disrupt you in ways you may not realize.

“Noise is not just causing annoyance, but it actually makes us sick,” said Dr. Thomas Münzel, a professor at Johannes Gutenberg University Mainz. “Regardless of where the sound is coming from, if it gets louder than 60 decibels (分贝),it can increase the risk of heart disease.”

When our body hears these noises, it reacts with a stress reaction. In this case, these sudden and unexpected noises cause hormones(荷尔蒙) to speed up and eventually damage the heart. Although the chance that a single noise will affect you is unlikely, it’s the continuous exposure (接触) to the sound that can finally affect you.

“But our heart health isn’t the only cause for concern. Long-term noise may also raise the risk of type 2 diabetes (糖尿病), depression, and anxiety disorders,” he warns. In the future, Münzel plans to examine how noises from cars, planes, and other vehicles affect the brain. But despite the amount or the depth of research he conducts, it’ll take the help of politicians to improve the effect of noise on our health.

“Politicians have to take into account, in particular, the new findings,” Münzel said, “As for aircraft noise and airports, it is important to make new laws and set new lower noise limits that protect people living close by the airport instead of the owners of the airport.”

4 . Turtles have a habit of eating plastic objects floating in the sea, which may kill them. Many believe that it is because floating plastic bags look similar to jellyfish, which many types of turtles love to eat. However, lots of plastic objects that turtles eat do not look like jellyfish at all. Joseph Pfaller of the University of Florida doubts that the smell of sea micro-organisms（微生物） which live on floating plastic objects attract turtles to eat.

The kind of idea first appeared in 2016. Researchers at the University of California, Davis, noticed that certain chemicals, especially dimethyl sulphide（二甲基硫）, which can be found on plastics where micro-organisms live, are those which many seabirds sniff（嗅）to find food. These birds are more likely to eat plastics.

Since turtles usually appear above the sea surface and sniff the air when going to their feeding areas, Dr. Pfaller believed that they are following these same chemicals like those seabirds and mistakenly think that floating plastic objects are edible.

To test that idea, he and his team did an experiment using loggerhead turtles. They exposed 15 turtles to four smells: the smell of clean water; the smell of turtle-feeding food; the smell of a clean plastic bottle; and the smell of a bottle that had been kept in the ocean for five weeks to allow micro-organisms to grow on it. When sniffing both the smell of turtle-feeding food and that of five-week-old bottles, turtles kept their noses out of the water more than three times as long, and took twice as many breaths as they did when sniffing the smell of fresh bottle-plastic or clean water.

Though they have not yet tested whether dimethyl sulphide on the five-week-old bottles cause turtles to eat plastic objects, Dr. Pfaller and his team think it is highly possible.

5 . Eating too much fatty food, exercising too little and smoking can raise your future risk of heart disease. But there is another factor that can cause your heart problems more immediately：the air you breathe.

Previous studies have linked high exposure (暴露) to environmental pollution to an increased risk of heart problems，but two analyses now show that poor air quality can lead to heart attack or stroke (中风) within as little as a few hours after exposure. In one review of the research, scientists found that people exposed to high levels of pollutants (污染物) were up to 5% more likely to suffer a heart attack within days of exposure than those with lower exposure. A separate study of stroke patients showed that even air that the U. S. Environmental Protection Agency (EPA)considers to be of “moderate” (良好) quality and relatively safe for our health can raise the risk of stroke as much as 34% within 12 to 14 hours of exposure.

The authors of both studies stress that these risks are relatively small for healthy people and certainly modest compared with other risk factors such as smoking and high blood pressure. However, it is important to be aware of these dangers because everyone is exposed to air pollution regardless of lifestyle choices. So stricter regulation by the EPA of pollutants may not only improve environmental air quality but could also become necessary to protect public health.