Bottled water has become the choice for people who are healthy and thirsty. Bottled water is all over the world. But some say the planet's health and people's health may be suffering from it.

The idea that bottled water is safer for humans may not be true. The Natural Resources Defense Council of America said. "There is no promise that because water comes out of a bottle, it is cleaner or safer than water from the tap." Another New York City-based action group added that some bottled water is "really just tap water in a bottle—sometimes cleaner, sometimes not."

It is not tested that bottled water is better than tap water. Nick Reeves from the Chartered Institution of Water and Environmental Management said, "The high mineral content(矿物质含量) of some bottled water makes them not good for feeding babies and young children. "Also, most bottled water doesn't have fluoride(氟化物), which can make teeth stronger. Kids are drinking more bottled water and less fluoridated tap water, and some say that's behind the recent rise in bad teeth.

Storing is another problem. Placed near heat, the plastic bottles can produce bad chemicals into the water. Store bottled water appropriately. Bottled water, like many foods and drinks, should be stored in the appropriate way to keep the quality and safety of the product. Keep bottled water out of the light and heat.

According to the Environmental Protection Agency, some 2.7 million tons of plastic are used worldwide to bottle water each year. The plastic can take between 400 and 1,000 years to break down.

For energy use, plastic bottles are also not cheap. One report said that if water and drink bottlers had used 10 percent recycled materials in their plastic bottles, they would have saved about 72 million gallons of gas.

So, if you are worried about the effect of bottled water on the earth, you can take the following four steps:

Step 1. Drink from your tap. Unless your government warns against this, it should be fine.

Step 2. Get a container(容器). Carry your tap water in a steel or a lined drinking container, and clean it between uses.

Step 3. Keep it cool. Don't drink from a bottle that has been sitting in the sun, don't store it near chemicals, and don't reuse plastic bottles.

Step 4. Choose glass containers over plastic if possible. When finished, recycle!

It’s hard to turn down junk food. However, eating too much is bad for your body, especially if you’re between the ages of 10 and 19. “Junk food shapes teenage brains in ways that make their ability to think, learn and remember weaker. It can also make it harder to control bad behaviors. It may even up a teen’s risk of mental (精神上的) problems,” said Amy Reichelt, a scientist at Western University, Canada.

Reichelt and two other researchers reviewed more than 100 studies about how poor food choices can make a big difference to teenage brains. They found teenagers are more sensitive (敏感的) than any other age group to foods with a lot of fat and sugar, as their brains are not yet fully formed.

Teenage brains are still developing the ability to notice risks and control actions. The prefrontal cortex (前额皮质) is the part of the brain tells us we shouldn’t eat chips all the time and helps us control ourselves. However, this part doesn’t fully develop until we are in our early 20s. At the same time, teen brains get more excited from prizes. The parts of the brain that make us feel good when we do something happy—like eating tasty foods—are fully developed by the teen years.

As a result, the teen brain has two hits against it when it comes to refusing junk food. Reichelt and her team did an experiment using mice, whose brains develop much like our own. They discovered that “teenage” mice that had high-fat foods performed worse on memory tests than those eating normal foods.

So, what’s the best way to say no to junk food? The answer is exercise. When we exercise, the brain becomes less sensitive to food, besides this, it also helps our brains grow and become better able to make wise decisions.

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