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Everything to know about Ozone (O3)

Ozone (O3), specifically at the ground level, is a common air pollutant recognized by many standard air quality guidelines, including the World Health Organization’s. At Breeze Technologies, ground-level ozone is among the many pollutants we measure, and is thus on our air quality index (AQI). Read on to find out why.

What is ozone?

Ozone (O3) is a gas that exists in two levels of the atmosphere: the stratosphere (upper level) and the troposphere (ground level). In the stratosphere, ozone is naturally-occuring and considered good as it protects the Earth by filtering out UV radiation from the sun. On the other hand, ground-level ozone, also called tropospheric ozone, is a greenhouse gas, an air pollutant, and a major component of smog. It is a pale blue gas with a pungent smell, and is formed through the photochemical reactions of other pollutants. Tropospheric ozone is a short-lived climate pollutant with an atmospheric lifetime of a few hours to a few weeks. 

What are sources of ozone?

Because ground-level ozone is a secondary pollutant, it doesn’t have any direct emissions sources. Instead, existing air pollutants such as carbon monoxide (CO), methane (CH4), nitrogen oxides (NOx), and volatile organic compounds (VOCs) undergo photochemical reactions from strong sunlight and UV radiation to form tropospheric ozone. This is why O3 levels typically peak in the summer due to the heat and sunlight.

These pollutants are created by human activities including:

  • Vehicles
  • Fossil fuel power plants
  • Oil and chemical refineries
  • The agricultural sector

Indoor sources stem from electric motors in household appliances like copiers and laser printers.

What is the health impact of ozone?

Ozone is suspected to have carcinogenic effects. It leads to reduced lung function and respiratory diseases, with exposure linked to premature mortality. Long-term O3 exposure is responsible for 1 million premature deaths a year due to respiratory complications. Chronic effects of ozone include:

  • Decreased lung function
  • Aggravated lung diseases (asthma, emphysema, chronic bronchitis, chronic obstructive pulmonary disease (COPD))
  • Lung cancer

What is the environmental impact of ozone?

Ozone is a strong greenhouse gas because of its ability to absorb radiation. Ground-level ozone not only increases climate warming, but also impacts evaporation rates, cloud formation, precipitation levels, and atmospheric circulation.

O3 is toxic to many plants and thus damages vegetation. It contributes to forest decline and up to a 15% annual yield loss of soy, maize, rice, and wheat. Estimated global crop production losses due to ozone total 79-121 million tonnes, which is worth USD 11-18 billion annually. Tropospheric ozone also accelerates the deterioration of rubbers, dyes, paints, coatings, and various textiles.

How can ozone emissions be lessened?

As ground-level ozone is a secondary pollutant, the best way to lower its levels is to reduce the emissions of its precursor pollutants. The U.S.’s Environmental Protection Agency (EPA) recommends implementing strategies such as:

  • Having vapour recovery nozzles at gas pumps
  • Using cleaner burning gasoline formulated to reduce other pollutants
  • Setting strict NOx emission limits for industrial combustion sources
  • Providing enhanced vehicle inspection programs
  • Enforcing strict limitations on solvent usage in factories

These measures, however, are only effective with proper monitoring. Tracking the changes in O3 emission levels will help gauge the success of these actions. And at Breeze Technologies, we have the perfect solution. Our compact, lower-cost sensors are easy to deploy on urban infrastructure, with the data gathered in real-time to form an effective air quality network run on our Breeze Environmental Cloud. Not only do we measure for O3, we also monitor its precursor pollutants, including CO, NO, NO2, and VOCs. Contact us today to make clean air a reality for all!