October 15^th is the Global Handwashing Day. Activities are planned in more than 20 countries to get millions of people in the developing world to wash their hands with soap. For example, donators (捐赠者) will give 150,000 bars of soap to schools in Ethiopia.

    Experts say people around the world wash their hands every day, but very few use soap at so-called important moments. These include after washing the toilet, after cleaning a baby and before touching food.

    Global Handwashing Day is the idea of the Public-Private Partnership for Handwashing with Soap. Partners include the United Nations Children's Fund, American government agencies, the World Bank and soap makers Unlever and Procter and Gamble. The organizers say all soaps are equally effective at removing disease-causing germs(细菌). They say the correct way to wash is to wet your hands with a small amount of water and cover them with soap. Rub(揉搓) it into all areas, including under the fingernails. Rub for at least twenty seconds. Then rinse well under running water. At last, dry your hands with a clean cloth or wave them in the air.

    The Partnership for Handwashing says soap is important because it increases the time that people spend in washing hands. Soap also helps to break up the dirt that holds most of the germs. And it usually leaves a pleasant smell. The Partnership for Handwashing also says washing with soap before eating or after using the toilet could save more lives than any vaccine(疫苗) or medicine. Hand washing could also prevent the spread of other diseases. When people get germs on their hands, they can infect(感染) themselves by touching their eyes, noses or mouths. Then they can infect others.

    We bet that on cold winter days, many of you love to stay in your warm home and, every now and then, come out into the kitchen for a snack. Unfortunately, plenty of small insects like to do the same thing! Winter is the time when small insects enter your house without an invitation. The season can be difficult for such creatures. In winter the air is cold, the ground is hard and many trees have no leaves. So small insects do what they have to do to survive.

    Monarch butterflies head south to warmer climates. Ants crowd in deep underground colonies and eat food they have been storing all year. Many insects go into a deep sleep called diapauses. There're different kinds of diapauses, but all are similar to hibernation, a time when bigger animals become inactive in the cold. Insects go into an inactive period, too, but it often isn't when the temperature drops.

    They rely on more dependable signals in the environment. For example, many insects can tell how much sunlight there's each day. They use that to tell themselves when to shut down. Insects are cold-blooded, meaning that their inside temperature is the same as the outside. They can't move much when it gets below 40 degrees Fahrenheit. So they search for any warm place.

    They're looking for protection. These guys have been doing this for 300 million years, so they don't really know they're coming into your house. The home is a recent event in terms of their evolutionary (进化的) behavior. They enter through tiny cracks or come in unnoticed on your clothes or shoes. Remember that they may be entering your homes for warmth and food, but they don't care about humans.

Plastic is everywhere, from the Arctic ice to vital organs in the human body. In fact, previous estimates suggest that the average person swallows a credit card-worth of microscopic plastic particles(颗粒) every week. But new research shows that this could actually be an understatement. 

Microplastics are plastics smaller than 5 millimeters, found in industrial waste, beauty products, and formed during the degradation of larger plastic pieces. Over time, they break down into even smaller nanoplastics. These tiny particles can pass through our intestines and lungs into our bloodstreams, reaching vital organs like the heart and brain. 

While the idea of eating plastic is unsettling in itself, the major concern here is that these plastic particles contain chemicals that can interrupt our body's natural release of hormones, potentially increasing our risk of reproductive disorders and certain cancers. They can also carry toxins(毒素) on their surface like heavy metals. 

In the past, researchers have shown bottled water can contain tens of thousands of identifiable plastic fragments in a single container. However, until recently, only the larger microplastics were detectable with available measuring tools, leaving the area of nanoplastics largely a mystery. 

Using Raman microscopy (显微镜学), capable of detecting particles down to the size of a flu virus, the team measured an average of 240, 000 particles of plastic per liter of bottled water, 90 percent of which were nanoplastics, a revelation 10 to 100 times larger than previous estimates. 

These plastics likely originate from the bottle material, filters used to "purify" the water, and the source water itself. "It is not totally unexpected to find so much of this stuff, " the study's lead author, Columbia graduate student Naixin Qian, said in a statement. His team hopes to expand their research into tap water and other water sources to better inform our exposure to these potentially dangerous particles. "The idea is that the smaller things get, the more of them I reveal, " he added.