People can live for 5 weeks without and food, 5 days without water, but without air, they can not live even for 5 minutes. People always ask themselves why so many odd diseases occur when we have the advanced economy and technology nowadays? For example, there are SARS, bird flu and so on. In addition, more and more people suffer from cancers and leukemia and among them, many are kids. All of these is related to people’s diet and life habits. But the polluted air is the chief cause. Facing to those threats, what can we do to improve the air condition?

First, people need to clean up often. Cleaning can drive away dusts and dirt which are the carriers of bacteria. Generally speaking, people use some damp cloth to wipe away dirt on furniture and other objects, and a mop to keep the floor clean. Besides, put bedclothes in the sun so that ultraviolet rays can kill the bacteria.

Second, people need to refresh the indoor air often. Open windows to let the fresh air in and dirty air out. But pay attention to the temperatures and seasons. Generally, oxygen is high in the air in the morning or after the rain. And there is less dust and pollutants at that time. Thus, it is the ideal time for opening windows to refresh the air. In summer, people need to open windows both in the morning and evening. They can open all the windows for a longer time. But in the noon, they’s better close windows in case that hot outdoor air comes in and arises the indoor temperature. If people feel it is too hot indoors, they can sprinkle some water on the floor which can cool the room, prevents dusts, and increases moist. In spring and fall, it is proper to open windows in the morning, but not for a long time. In winter, it is also appropriate to open windows in the morning to decrease the carbon dioxide. But it is cold then. Make sure everyone stay warm when windows are open. Generally, open the windows for more than 20-30 minutes per week, but it depends on the particular season and temperatures.

Third, people need to purify the air often. The common tool is air purifier which can clear away air pollutants such as tiny dusts, bacteria, and smoke. It gives clean and purified air out through blocking and filtering pollutants. Experts suggest choose reliable air purifier.