Air Quality
National Air Quality
National air quality has improved since the 1990's, but many challenges remain in protecting public health and the environment from air quality problems. Air pollution in the United States poses a public health threat affecting potentially millions of people throughout the country.
Air pollution is associated with health problems that include increased emergency department visits and hospital stays for breathing and heart problems, asthma, and increases in illnesses such as pneumonia and bronchitis.
Air Quality in Louisiana
Air Contaminants
Ozone is a gas that you cannot see or smell. Ozone occurs naturally in the sky about 10 to 30 miles above the earth's surface. Sometimes, this ozone is called "good ozone" because it forms a layer that protects life on earth from the sun's harmful rays. Ground-level ozone, on the other hand, can be bad for your health and the environment.
Ground-level ozone forms when pollutants from cars and trucks, power plants, factories, and other sources come in contact with each other in heat and sunlight. Factors such as weather conditions and intensity of sunlight also play a part in how ozone is formed. Ground-level ozone is one of the biggest parts of smog, and it is usually worse in the summer months. Many urban areas tend to have higher levels of ground-level ozone. However, rural areas have ground-level ozone, too. Wind carries ozone and the pollutants that form it hundreds of miles from their original sources, and rural areas have sources of ozone that contribute to this problem.
Particle pollution includes:
- coarse particles that are between 2.5 and 10 micrometers
- fine particles that are between 0.1 micrometers and 2.5 micrometers; also known as PM2.5
- ultrafine particles that are smaller than 0.1 micrometers
Particles bigger than 10 micrometers can irritate your eyes, nose, and throat but do not usually reach your lungs. Ten micrometers is about seven times thinner than one human hair.
Fine and ultrafine particles are the most concerning because they are most likely to cause health problems. Their small size allows them to get into the deep part of your lungs and even into your blood.
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