How does ozone affect human health?

Ozone in the upper atmosphere protects the DNA of all surface-dwelling (and near-surface-dwelling ocean) life. In our atmosphere, ozone is found in varying concentrations at different altitudes, with the highest concentration (the "ozone layer") located in the lower stratosphere. Ozone inhaled can cause damage and constriction in the airways. It behaves similarly for our food supplies, reducing crop yields (plants breathe through their leaves). It can kill, improperly applied. So ozone in high concentrations (>0.05 ppm) in the troposphere is considered a pollutant. Ozone and other powerful oxidants are produced in tiny amounts by white blood cells in fighting infections. Likewise, marigolds produce ozone from their roots when predators attack the roots. Ozone rinses (ozone dissolved in water... not liquid ozone) have been used on teeth in Europe, where it kills all the bacteria that attack teeth. Ozone rinses have been used in rebuilding cartilage in back injuries and damaged knees. Ozonated ointments have been used to fight local infections for short periods. Ozone is used to sterilize the water some of us drink (both municipal and bottled), and the bottles that we may drink it from. The ozone layer protects the skin from short wwave UV that can cause mutation and skin cancer. Human skin is largely impervious to tropospheric ozone (but lungs are not). The name "ozone layer" refers to a region near the bottom of the stratosphere where there is sufficient oxygen and enough energetic UV that ozone can be formed. Tropospheric ozone (such as in a room or a city) aggrevates asthma, ages rubber (tires, carpet backing), destroys / damages a plant's ability to make oxygen, inflames lung tissue and so on. Ozone's affects on health are well documented. But nothing lives (that we depend on) at the bottom of the stratosphere. It keeps the sun's most harmful rays from reaching the earth. If we destroy it, we will burn... it is very beneficial, in other words! I hope this helped!!