Solo disponible en BuenasTareas
  • Páginas : 9 (2009 palabras )
  • Descarga(s) : 9
  • Publicado : 19 de agosto de 2010
Leer documento completo
Vista previa del texto
Clean Air and Dirty Air | |
|On a clear breezy day, the air smells fresh and clean. Clean air is air that has no harmful levels of pollutants (dirt and | |
|chemicals) in it. Clean air is good for people to breathe. | |
|| |
|On a hot day with no wind, the air can feel heavy and have a bad smell. Once in a while, the air can even make your chest feel | |
|tight, or make you cough. When too much dirt and chemicals get into the air, the air is dirty or polluted. Dirty air is not | |
|good for people to breathe.| |

|Dirty Air Can Make You Sick |
|When the air has some dust, soot or chemicals floating in it, people who are inside probably won't notice it. People who are |
|outside might notice it.|

|People with asthma, a disease that can make it hard to breathe, and children who play outside a lot might feel a little strange. |
|When you are active outdoors, for example, when you run and jump a lot, you breathe faster and take in more air. Any pollutants |
|in the air go into your lungs|

When the air is very dirty, almost everyone will notice it. It would be good if we could stop breathing on those days, but of course we can't!
|How Can I Tell if the Air is Clean or Dirty? |
|Have you ever been stopped behind a truck|[pic]|
|or a bus at a traffic light? When it | |
|starts up, sometimes a puff of dark smoke| |
|comes out of the exhaust pipe. ||

|At times like that you can see dirty air - it looks hazy and brownish. If your window is open, you might be able to smell the |
|pollution. But sometimes the air can be dirty and you can't see it or smell it. So you need another way to tell if the air is |
|dirty. This is why EPA developed the Air Quality Index, which we will describe in the"What is the AQI" section. |

|[pic] |[pic] |
|Clean Air |Dirty Air or Pollution |

|The Environmental Protection Agency|
|The environment is everything around you - the air, the land, and the rivers and oceans. The Environmental Protection Agency | |
|(EPA) is a government office that works to keep the air, the land, and the water clean. Clean air, land, and water help keep us| |
|healthy. The EPA works with state environmental agencies to keep the air clean. Stateenvironmental agencies take samples of | |
|the air at more than 1000 places in the United States to see if the air is dirty or clean. | |


|Pollutants are what make the air dirty and cause pollution. Five pollutants are used by the EPA to determine the Air Quality |
|Index (AQI). Two of the pollutants, Ozone and Particulate Matter, make...
tracking img