Understanding Ozone
Each summer, ground-level ozone presents Clark County’s greatest air quality challenge. What causes ozone? How is it created and what can we do about it? Watch this video and learn how you can help us protect the air we share.

How Does Ozone Form?
Ground-level ozone is formed when volatile organic compounds (VOCs) mix with oxides of nitrogen (NOx) in ultraviolet rays and heat. VOCs are emitted gases from fumes from fuel, paints, chemicals, personal care products and even some plants and vegetation.

Examples of NOx emissions are vehicle exhaust, gases from industry and wildfire smoke. Stagnant weather conditions and the topographic structure of the Las Vegas Valley help trap these pollutants, causing levels to rise. Exposure to ozone can irritate your respiratory system and cause coughing, a sore throat, chest pain and shortness of breath even in healthy people, according to the EPA.

What is an Ozone Exceedance?
According to the EPA, an exceedance for ground-level ozone occurs when ozone concentrations are greater than 70 parts per billion (ppb) over the course of eight rolling hours per 24 hours in a day. As concentrations of ground-level ozone increase, so increases the Air Quality Index.

Air Quality Index
The Air Quality Index (AQI) is a measurement tool to gauge air pollution. It runs from 0 – 500 and is used to measure six pollutants: carbon monoxide, lead, nitrogen dioxide, ozone, particulate matter and sulfur dioxide. The higher the AQI value, the greater level of air pollution and greater the health concern.