Unraveling Ozone

Unraveling Ozone


AQ Instagram_advise-smoke&ozoneClark County’s Division of Air Quality (DAQ) issued a season-long advisory for ground-level ozone pollution and wildfire smoke today that will be in effect from Monday, April 1 through Monday, Sept. 30. Air quality forecasters say the increased chance of wildfire smoke drifting into Southern Nevada can influence ozone formation as well as increase particulate matter pollution.

“Because of our summer weather, topography, homegrown pollutants and proximity to Southern California—from where ozone-producing pollutants and wildfire smoke can transport in our direction— we will likely have days this summer when ozone concentrations in the Valley exceed the EPA’s standard,” said DAQ Senior Meteorologist Paul Fransioli.   

Click here for the advisory.

Understanding Ground-Level Ozone
You have questions. We've got answers. Click a topic below for helpful videos, infographics and information to help you understand ozone, how it impacts local air quality (and your health) and how you can help reduce ozone.

Unraveling Ozone What is an Ozone Exceedance? How Does Ozone Form? What are We Doing About Ozone? If You Have Breathing Sensitivities Helpful Tips to Reduce Ozone

Unraveling 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.

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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. This chart provides a year-over-year total of days when ozone concentrations exceeded the current 70 ppb standard.

Exceedance Tracker_ 71 ppb or HIGHER 2 (4)

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.

AQI Chart
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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.

Ozone 2022_FB wHarms

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.

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What are We Doing About Ozone?
Short answer: a lot. In addition to our regulatory duties of compliance and permitting actions toward local businesses with active air permits, we also monitor local air quality and keep you informed if and when ozone, dust or other particulate matter may impact outdoor air quality.

Currently, we are developing a series of new rules, designed to reduce homegrown, ozone-producing pollutants. The goal of these rules is to reduce ozone concentrations in Clark County to fall below the U.S. Environmental Protection Agency’s standard for ozone. As this chart below depicts, ground-level ozone in Clark County has reduced greatly over the past 20 years or so. Nevertheless, we’re working every day to improve it.

Ozone Chart_Design Values_smol


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AQ Tips_FB - breathing
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AQ Tips_FB-reduce ozone

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