Surface Ozone Vs. The Ozone Layer
Although the ozone found at the Earth's surface is the same chemical species as that found in the ozone layer, they have very different sources, atmospheric chemistry, and affect human health differently as well. The ozone layer protects people from the sun's most damaging ultraviolet rays. Because the ozone layer is located high in the atmosphere, people are not directly exposed to it.
Ground-level ozone, however, is a health hazard because people breathe it. It is formed through a complex set of chemical reactions involving hydrocarbons, nitrogen oxides and sunlight on calm summer days where the weather may also be warm and humid . High levels of ground ozone affects the breathing process and aggravates asthma in chronic sufferers. The young, elderly, and those with lung diseases are especially susceptible.
Ozone is most likely to exceed safety limits from May through October when seasonal heat and sunlight are at their highest . However, similar conditions can occur at other times of the year in specific urbanized areas; namely the Los Angeles area, which is well known for smog formation.
Read more about this topic: Ozone Action Day
Famous quotes containing the words surface and/or layer:
“White Pond and Walden are great crystals on the surface of the earth, Lakes of Light.... They are too pure to have a market value; they contain no muck. How much more beautiful than our lives, how much more transparent than our characters are they! We never learned meanness of them.”
—Henry David Thoreau (1817–1862)
“The writer in me can look as far as an African-American woman and stop. Often that writer looks through the African-American woman. Race is a layer of being, but not a culmination.”
—Thylias Moss, African American poet. As quoted in the Wall Street Journal (May 12, 1994)