Are You Being Exposed to Too Much Ozone?

Those of us living in urban or suburban areas may have seen the occasional summer news report about ozone alerts, but many of us may not be aware of what this really means.

Naturally found in small concentrations in the Earth’s upper and lower atmosphere, ozone is a molecule consisting of three oxygen atoms bound together, and is often used as a deodorizing agent, sterilization agent for air and drinking water, and even as a bleach. In fact, some air purifier manufacturers have also touted the use of ozone as a miracle “air cleaner” and they specifically design air purifiers which utilize ozone as a means to sterilize the air. While ozone molecules may be able to destroy some airborne pollutants, even low concentrations of ozone gas can be considered toxic, as it is ozone’s ability to alter the chemical composition of other substances that can also cause adverse health reactions.

When ozone is inhaled, it travels through your respiratory tract and its corrosive nature damages the alveoli and bronchioles in your lungs. After repeated exposure, ozone can inflame lung tissue and cause other respiratory illnesses and even infection. Ozone can also aggravate or exacerbate existing conditions such as asthma and allergies, and it is for this reason that the California Air Resources Board has agreed to ban the sale of ozone air purifiers by 2009.

Nevertheless, even if you don’t employ the use of ozone air purifiers in your home, you can still be susceptible to high levels of ozone if you live in non-urban areas. Prevailing winds or car emissions traveling through rural areas often carry ozone pollution, and significant levels of pollution can be detected in rural areas as far as 250 miles downwind from urban industrial areas.

To protect yourself from ozone exposure, pay close attention to the Air Quality Index (AQI) in your area on a daily basis, and you can usually find this information in the newspaper, on a morning weather forecast, or on the internet. Generally speaking, AQI measures the concentrations of five specific air pollutants: ozone, sulfur dioxide, particulates, carbon monoxide, and nitrogen dioxide, and these concentrations are compared to a standard set out by federal law. Also follow these steps to decrease ozone exposure:

1. Eliminate or control sources of ozone: Perhaps the most effective method of decreasing ozone, you can eliminate or control ozone by minimizing the use of products and materials that cause indoor pollution; employ good hygiene practices to minimize biological contaminants; and using good housekeeping practices to control particles.
2. Increase ventilation: This includes installing an exhaust fan close to the source of contaminants, increasing outdoor air flow in a mechanical ventilation system; and opening windows.
3. Remove pollutants through proven air cleaning methods: This can include using air purifiers that employ the use of mechanical filtration, such as HEPA or Activated Carbon air purifiers. One air purifier manufacturer – Airfree – has also designed a line of air purifiers scientifically proven to actually decrease ozone levels in a given environment.

Lastly, if you’d like to test the ozone levels in your own backyard or around your school, you can make ozone detector strips from simple ingredients including corn starch, coffee filters (cut in strips), and potassium iodide. Make a paste from water, cornstarch, and the potassium iodide and paint this paste on the filter. After exposing the strips to the air for eight hours, airborne ozone will react with the potassium iodide and change the color of the strip. Here is the color scale with the corresponding ozone concentrations:

Schoenbein Color Scale for Ground Level Ozone Testing

0-3: Little or no change
4-6: Lavender
7-10: Blue or purple