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What is Ozone? Why is it Bad?

Ozone is a highly reactive gas that consists of three oxygen atoms. It has the same chemical structure whether it occurs miles above the earth or at ground level. Depending on its location in the atmosphere, ozone is considered either good or bad.

Ozone is naturally occurring in the stratosphere and forms a layer that protects life on earth from the sun's harmful ultraviolet rays. The term "ozone hole" refers to a reduced concentration of ozone in the stratosphere.

At ground level (also known as the troposphere), ozone is considered bad. Ground level ozone causes human health problems, damages crops and other vegetation, and is a main contributor of smog. Ground level ozone is created by photochemical reactions between nitrogen oxides (NOx) and volatile organic compounds (VOCs, or hydrocarbons) in the presence of sunlight. NOx is a product of combustion and comes from various sources, like power plants and automobiles. VOCs are the result of incomplete combustion or simple evaporation of fuels and solvents.

The reaction between NOx and VOCs occurs more readily during the hot summer months. Ground level ozone can also be transported hundreds of miles. For instance, ozone can be “transported” from the Chicago/Gary area across Lake Michigan where shoreline monitors often measure high ozone concentrations due transport from these upwind areas.

Ground level ozone is unhealthy to breathe as it can narrow airways. Individuals most susceptible to ozone exposure include those with respiratory disease, children, and adults who actively exercise or work outdoors. Human exposure to elevated concentrations of ozone can include the following effects:

  • Eye irritation;

  • Difficulty breathing or shortness of breath;

  • Coughing and chest pain;

  • Aggravation of asthma;

  • Susceptibility to respiratory infections; and

  • Repeated exposures could result in irreversible damage to the lungs.

Ozone is most likely to exceed safe limits from May through October when seasonal heat and sunlight are at their highest. An “Ozone Action Day” is declared at certain times during the months when weather conditions (heat, humidity and stagnant air) favor the formation of ozone.

Basic steps in reducing ground-level ozone during Ozone Action Days are:

  • Eliminate excessive automotive engine idling, avoid rush hour when slowdowns on roads are most common, and park and go inside instead of idling in drive-thru lines;

  • Ensure your vehicle is functioning properly by maintaining the exhaust system, proper air pressure in tires, and stating current with scheduled oil changes;

  • Avoid unnecessary driving by combining trips and carpooling;

  • Refuel after 6:00 pm (or after dusk) and do not ‘top off’;

  • Take public transportation (some cities provide free or discounted public transportation on Ozone Action Days);

  • Walk or ride a bicycle; and

  • Avoid commuting by working from home.

At home reduction activities include:

  • Limit the use of lawn mowers and outdoor grills to after 6:00 pm;

  • Limit the use of aerosol cans around the home;

  • Conserve energy by turning the air conditioning thermostat up, utilizing fans, turning the thermostat up when not at home, and closing blinds to reduce sun penetration;

  • Turn off or unplug electrical devices when not in use (computers especially can heat up rooms);

  • Install LED lights that utilize less energy. The price for LED lights are now more affordable, and many electric companies offer subsidized pricing at local stores such as Home Depot, Lowes and Ace Hardware;

  • Some cities prohibit outdoor burning during Ozone Action Days. Even if not prohibited, avoid outdoor burning.

CFR has a long history of helping industry reduce their VOC emissions. Not only will this save dollars, it will also lead to a tangible difference in the surrounding air quality. Contact us today for a free initial consultation.

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