191 



OZONE 



HUMAN-CAUSED 

 OZONE 



The second type of pollution Is ozone. You may have heard 

 recent news reports about the hole in the ozone layer over 

 Antarctica. This stratospheric ozone is a natural occurrence 

 and is needed to filter harmful ultraviolet light from the sun's 

 rays. However, human-caused ozone found down here in the 

 air we breath is harmful to people and is suspected of 

 damaging many species of plants. 



This pollutant does not actually come out of a smokestack or 

 auto tailpipe but is "created" in the atmosphere as a result of 

 a chemical reaction between volatile organic compounds 

 (VOC's) and nitrogen oxides (NOx). VOC's enter the 

 atmosphere as fluids, such as gasoline, printing ink, cleaning 

 solvents, and dry cleaning solvents, then they evaporate. 

 Nitrogen oxides, like sulfur dioxide, are given off by the 

 industrial burning of fossil fuels and by auto emissions. 

 Concentrations of ozone in the Park have been found that are 

 higher than in many cities. On a few occasions, levels have 

 exceeded the federal health standards. Ozone is a poisonous 

 form of oxygen which can damage both plant and animal 

 tissue. In humans it irritates the pulmonary membranes, can 

 cause coughing, sinusitis, chest pains and a general feeling 

 of weakness. It can also aggravate asthma and other 

 breathing disorders, making attacks more frequent or severe. 

 Some normally healthy people are particularly sensitive to 

 ozone and can feel its effects at low levels of concentration. 



WHAT CAN 1 DO? 



If the ozone rating today is unhealthy, you may wish to 

 refrain from strenuous physical exercise. People with 

 respiratory ailments should limit their exposure by staying 

 indoors. 



Keep informed of efforts in your community, at the local, 

 state or federal level, and support those efforts to clean up 

 our airl 



v <c^% 



'O/VAX. 



