Be Air Aware

Helping Out

Health-based air quality standards are met with a combination of planning, regulation, enforcement, technical innovation, grants and incentives, and public participation. The public plays a large part in achieving clean air goals. Depending on the season, there are several ways that your actions can benefit the health and wellbeing of people in your neighborhood, Butte County, and throughout the Sacramento Valley.


In the summertime, we are trying to reduce the amount of ozone-producing gases that are emitted by burning fuels. Carpooling, taking a bus, or riding a bike instead of driving, even just now and then, goes a long way towards reducing air pollution. Find the B-Line schedule at

The B-Line website also has the Chico Bike Map at
Head to for trails in the Oroville Area.

If you’re researching cleaner, fuel efficient vehicles, check out for information. There are rebates available for qualifying plug-in hybrid and electric cars at


During the late fall and winter months is when Butte County experiences the highest levels of particle pollution. Burning wood is common during these months for home heating and fire hazard reduction. Burning correctly will help reduce the amount of smoke your fire creates.

Burning in your woodstove:

  • Burning wet wood is a waste! Be sure wood is dry and well seasoned before burning.
  • Maintain a hot fire with good air flow.
  • During the months of November through February, Check Before You Light!
  • Consider upgrading to an EPA certified wood stove.

Burning outdoors:

  • Know that open burning outdoors is regulated in Butte County. Review the requirements at and on your Cal-Fire issued burn permit.
  • Refrain from burning wet or green material. It makes a lot of smoke!
  • Burning illegal materials such as garbage, plastics, dimensional lumber, and tires is prohibited.
  • Consider chipping and composting as alternatives to burning.
  • Be fire safe!

Sources of Air Pollution

There are many sources of outdoor air pollution that we encounter on a daily basis. Cars, woodstoves, gas stations, dusty roads, etc. For the most part, these air pollutants are only a health problem if they reach an elevated level. The particulates that we measure (PM2.5 and PM10) as well as smog-forming gaseous pollution from engine combustion (NO2) are known as criteria pollutants and are a concern if concentrations exceed health-based standards. Toxic Air Contaminants such as benzene and diesel particulate matter can also be a health concern even at low concentrations. Some pollutants are very localized while others can travel hundreds of miles before impacting an area.

Here are several common types of air pollution in Butte County:

Fine Particulates (PM2.5):
Fine particulates are extremely small particles that can penetrate deep into the lungs. These particulates are generally the result of combustion. Woodstoves, open burning, and wildfires all contribute to PM2.5 pollution. PM2.5 can also chemically form in the atmosphere on smoggy days. This contributes to the haziness seen during smog episodes.

Coarse Particulates (PM10):
Coarse particulates are slightly larger in size than PM2.5 and are mainly composed of dust and organic debris. Common sources of PM10 include fugitive dust from unpaved roads, tilling, construction, and agricultural product processing.

Ozone and Gases That Help Create Ozone
Ozone is a lung irritating gas that can be harmful at high levels. Ozone is not emitted directly into the atmosphere. Instead, other pollutants such as Oxides of Nitrogen (NOx), hydrocarbons, and Volatile Organic Compounds (VOCs) are involved in a chemical reaction with sunlight to create ozone. These ozone-forming pollutants are created from the combustion of fuels (gasoline, diesel, wood, natural gas). Nitrogen Dioxide (NO2) and Carbon Monoxide (CO) can also be harmful at high levels. VOCs are also emitted along with gasoline, paint, and solvent vapors.

Image Credit: CARB

So, what is the largest source of air pollution in Butte County? To find that answer, we can look at the Emissions Inventory for Butte County. An Emissions Inventory estimates the emissions from a variety of sources and considers population, traffic data, air pollution control technology, and many other factors.

The good news is that despite an increase in population, economic output, energy consumption, and vehicle miles traveled, air pollution emissions overall continue to decrease. Tomorrow we’ll wrap up Air Quality Awareness Week with ways that we all can help improve Butte County’s air quality.

Image Credit: US EPA

Be Air Aware

Residents of Butte County can find current, historical, and forecast air quality information from several sources. The monitors mentioned yesterday help air quality staff make daily forecasts. The data collected can also be uploaded along with meteorological data into computer models that can show how air pollutants are moving. Below is a list of several places online where you can find air quality information.

District Website: or
What You Can Find: Daily AQI forecast for Butte County

The Butte County Air Quality Management District website shows today’s (updated by 8:45am) air quality forecast. For desktop computer users, Today’s Air Quality is on the right hand column. If you’re accessing our webpage on a smart phone, just scroll down until you see it. The daily forecast shows the Air Quality Index (AQI) expected for the day in the Butte County cities where monitors are located. What does the AQI mean? See this page for a description of the different AQI levels. You’ll notice that the city names are hyperlinked in Today’s Air Quality. Click on the link and you’ll be sent to…

What You Can Find: Current and forecast AQI graphics and loops, AQI forecasts for all US cities

Airnow is a great resource for those that like to see air quality data visually. Computers collect data from all reporting monitors and help fill in the gaps. You can also click on the loop option to see how air quality has changed during the course of the day.
What You Can Find: A way to sign up for email alerts

Enviroflash is a service where you can sign up for emails if the AQI is forecast above a certain level in a city near you. For example, you could receive an email if air quality is expected to be Unhealthy for Sensitive Groups in Paradise. Our staff update Enviroflash daily with the AQI forecast.

The Breathe Well Mobile App:
What You Can Find: Current AQI for Ozone and PM2.5 in your nearest city…optimized for your phone or tablet!

The Breathe Well app is simply a mobile-optimized page that lets you know the current AQI near you anywhere in California.

Air Quality and Meteorological Information System (AQMIS):
What You Can Find: A large collection of California air quality and meteorological data including trends and special reports.

AQMIS is the California Air Resources Board public database for all the data collected at state monitors (including the air quality monitors in Butte County). For those that like to dig deeper, this a good resource to find raw daily and hourly data for various pollutants.
EPA Air Data:
What You Can Find: Air quality data with interesting visualizations and trends from around the United States of America.

Similar to AQMIS, this page can lead you to detailed air quality data. Butte County data is included once it is certified. This site also offers unique ways of visualizing air quality data to show trends. For example, here’s the highest AQI value measured in Butte County for each day since the year 2000:

Do you see the 2008 and 2012 wildfire smoke impacts?

Measuring Air Quality

There are various air pollutants that impact Butte County. Here’s a quick reminder of the two primary air pollutants of concern in Butte County:


Ground level or “bad” ozone is not emitted directly into the air, but is created by chemical reactions between oxides of nitrogen (NOx) and volatile organic compounds (VOCs) in the presence of sunlight. This is why ozone is a larger issue in the summertime. Emissions from industrial facilities and electric utilities, motor vehicle exhaust, gasoline vapors, and chemical solvents are some of the major sources of NOx and VOC. Breathing ozone can trigger a variety of health problems, particularly for children, the elderly, and people of all ages who have lung diseases such as asthma. Ground level ozone can also have harmful effects on sensitive vegetation and ecosystems.

Image credit: NASA

Particulate Matter (PM10, PM2.5):

PM stands for particulate matter (also called particle pollution): the term for a mixture of solid particles and liquid droplets found in the air. Some particles, such as dust, dirt, soot, or smoke, are large or dark enough to be seen with the naked eye. Others are so small they can only be detected using an electron microscope. Particulate matter contains microscopic solids or liquid droplets that are so small that they can be inhaled and cause serious health problems. Particles less than 10 micrometers in diameter pose the greatest problems, because they can get deep into your lungs, and some may even get into your bloodstream.

Image credit: US EPA


Various pollutants require a variety of air quality monitoring equipment. Additional equipment is required to support, calibrate, and validate air quality monitors. In addition to air pollution, most air quality monitoring stations also collect meteorological data so that air pollution impacts and trends can be compared against weather patterns.

The California Air Resources Board (CARB) maintains four air quality monitoring stations in Butte County. Ozone monitors are sited at the Chico and Paradise Airport stations and provide hourly values. Particulate matter is measured on an hourly basis in Chico, Paradise, and Gridley. The Chico monitoring station can also measure for carbon monoxide, nitrogen dioxide, and toxic air contaminants. The Chico station also has a monitor that can collect particulate samples for lab analysis to show what the particle is made of! Tomorrow, we’ll talk about how residents of Butte County can see data collected at these monitoring stations.

Chico Monitoring Station

Paradise Airport Monitoring Station

Paradise Theater Monitoring Station

Gridley Monitoring Station

The Butte County Air Quality Management District maintains a portable particulate monitor that can be deployed county-wide during exceptional events such as wildfires.

District E-BAM – Portable PM2.5 Monitoring Station

Air agencies are not the only ones collecting air quality data. Citizen scientists are starting to monitor air quality more and more as handheld monitors and sensors become more affordable.  See EPA’s page on Citizen Science for more information:

For additional air quality topics, visit the US EPA’s Air Quality Awareness Week webpage:

Butte County vs. The World

This week, we will be posting information that will help you “Be Air Aware.” To start things off, let’s take a look at how Butte County’s air quality measures up compared to the rest of the world and to the rest of California. It should be noted that there are various types of air pollution (more on that Tuesday) and it comes from a variety of sources (more on that Thursday).

Air pollution also varies on how large an area it impacts. Some types of air pollution dissipate quickly while others can travel around the world.  Here’s a timelapse of a special study performed by NASA in 2006-2007. Dust (red), sea salt (blue), organic/black carbon (green), and sulfates (white).

Taking a look at fine particulates (PM2.5 – the particles small enough to bypass your natural defenses), Butte County does remain under the U.S. EPA Annual Standard of 12 micrograms per cubic meter, as it did back in 2014 when the World Health Organization gathered a world-wide collection of air quality data. See the chart below to see how the Chico Metropolitan Area (Butte County) compared against other locations around the world.

Ozone (a key pollutant in summer smog) is a pollutant that impacts much of California due to the topography of the state combined with many sources of combustion. This is one pollutant that is still giving Butte County troubles, as we still exceed the federal standard. When compared to the other counties in California, Butte County is in the middle of the pack.

There are many ways to measure air quality. We’ll discuss how we do it here in Butte County on Tuesday. NASA has been developing new ways of measuring air quality from space! Below is a snapshot from 2014 showing Nitrogen Dioxide (NO2) concentrations around the world from NASA’s Aura program. NO2 is formed during the combustion of fuels, is a lung irritant, and contributes to summer smog.

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