The Dangerous Effects of Ozone

Triatomic oxygen, O3, is most commonly known as ozone. It has a

resonance structure, and can be drawn in two different ways:

O=O- O-O=O It is a bluish, explosive gas at room temperature, and has a

boiling point of -119?C. It has a melting point of -193?C, and is a

blue liquid. It's critical temperature and pressure are -12.1?C and

53.8 atm, respectively. It has a pleasant odor in concentrations of

less than 2 ppm, and is irritating and injurious in higher

concentrations. The density of ozone gas is 2.144 g/L, and the density

of ozone as a liquid is 1.614 g/mL. It is extremely unstable, and

solutions containing ozone explode upon warming. It is found in varying

proportions on Earth, but it is about 0.05 ppm at sea level.

Ozone absorbs harmful ultraviolet radiation in the upper atmosphere,

and protects humans from skin cancer. But ozone is also the main

ingredient of smog, and causes serious health effects and forest and

crop damage in the lower atmosphere. Ozone is formed through the

chemical reaction of volatile organic compounds and nitrogen dioxide,

in the atmosphere, in the presence of sunlight. This reaction is called

a photochemical reaction, because sunlight is required. The product is

known as smog. The notorious brownish color of smog is due to nitrogen

dioxide of the mixture. Increased temperature stimulate the reaction,

which is why ozone conditions are worse in the summer. It is an

oxidant, meaning it takes electrons away from other molecules, and

disrupts key structures in cells by starting chain reactions.

Ozone is a serious national problem. Half of the largest urban areas in

the United States exceed the ozone standards. The worst regions in the

US include California and the Texas Gulf coast, and the northeast and

the Chicago-Milwaukee area during the summer.

The ozone condition varies from year to year, as the temperature and

weather fluctuate. This fluctuation also occurs throughout the day, as

emissions from morning traffic builds up, the levels rise. Ozone

emissions come from many things, such as automobiles, gas stations,

power plants, dry cleaners, paint shops, chemical manufacturing pants,

oil refineries, and other business that release volatile organic

compounds.

The health effects of ozone are chest pain, coughing, wheezing, lung

and nasal congestion, labored breathing, sore throat, nausea, rapid

breathing, and eye and nose irritation. The symptoms occur when the

levels of ozone are only slightly higher than the legal standard.

Living in San Diego during my elementary school year, I personally felt

the effects of ozone; the tightness of the chest, wheezing, and labored

breathing on certain hot, humid days. Days would be labeled "smog

days", and children wouldn't be able to play outside during recess, the

air was so polluted. Heavy exercise can drive ozone deeper into the

respiratory system, and interferes with lung operation, and children

growing up in smog-polluted areas have been found to have lost 10-15%

of their lung capacity.

Ozone severely damages crops, forests, and man-made materials. The

crops affected are ones such as soybeans, peanuts, corn, and wheat, and