SonomaCountyRecovers: Official recovery information for Sonoma County fires

Air Quality in Sonoma County

How do we measure air quality?

One of the most common ways to measure air quality is by measuring particulate matter, or PM. PM refers to extremely small particles in the air that are detrimental to your health. PM2.5, also called “fine particulates,” consists of particles with diameters ≤ 2.5 microns. PM10 refers to “coarse particles” that have a diameter ≤ 10 microns. To learn more about PM, click here.

Air Quality Monitoring Data

Weather conditions and winds change dramatically during the winter months in the Bay Area. Frequently cool windless days will occur and an inversion layer sets in, a phenomenon when cooler air sinks and warm air aloft traps the air in our region. This causes air pollutants that we emit every day from driving, farming, industrial activities, and burning wood in fireplaces to build up and become trapped in the air.

Periodically, the Bay Area Air Quality Management District (BAAQMD) forecast higher particulate matter concentrations in the North Bay. This is often due to cooler temperatures in the North and the inland valleys and often trapped wood smoke pollution.

The winter weather pattern will continue intermittently throughout Napa, Sonoma, and Marin counties. By late February to early March, this pattern will switch to a spring weather pattern allowing for more air disbursement.

For Sebastopol: To find information on the most recent PM2.5 air quality data, please click here. 

For Cloverdale, Healdsburg, and Guerneville: To find information on the most recent Air Quality Index (AQI) by the Northern Sonoma County Air Pollution Control District, please click here.

Five-day forecast: If you’d like to see the current spare the air status and five-day forecast, please click here.

For map predictions, click on the forecast here

The Bay Area Air Quality Management District developed this legend to help you understand the PM2.5 data. As established by the U.S. Environmental Protection Agency (EPA), the Air Quality Index for PM2.5 is based on 24-hour concentrations, so hourly readings are only estimates.

Air Quality Index Levels of Health Concern Numerical Value
Good 0 to 50
Moderate 51 to 100
Unhealthy for Sensitive Groups 101 to 150
Unhealthy 151 to 200
Very Unhealthy 201 to 300
Hazardous 301 to 500
During northern California’s wildfire season, the Bay Area Air Quality Management District monitors general air quality in the Bay Area and will issue a health advisory if wildfire smoke appears to be causing elevated levels of particulate pollution in the region. The Sonoma County Department of Health Services receives community area monitoring data through US Army Corps of Engineers (USACE). The USACE is one of several agencies in Sonoma County conducting air monitoring to ensure the safety of the community. The PM 10 Average Concentration readings, in general, were below the target criteria indicating no reportable risk based on particulates as a result of these readings. The USACE is also overseeing area monitoring as part of debris management and clean-up. As of December 1, PM 10 Average Concentrations are being monitored during debris removal. PM10 includes inhalable particles with diameters that are generally 10 micrometers and smaller. PM10 is a more conservative approach to air monitoring, which captures everything below 10 micrometers, including PM2.5. PM 10 Average Concentration readings, in general, were below the target criteria indicating no reportable risk based on particulates as a result of these readings. On 12/14 and 12/15 PM targets were exceeded at the monitoring locations. These exceedances were evaluated and it was determined that they were due to increased vehicle traffic in the area. There were no exceedances for the offsite, downwind locations or nearest sensitive receptor. Additionally, maximum concentrations were all below targets and the maximum 3-hour averaged did not exceed action levels. Dust control measures in the form of watering and street cleaning were increased. Following these activities, PM10 levels at monitoring sites were below target levels. Updated as 7.27.18 See Fire Debris Removal Air and Area Monitoring tracking tables here Dec 1-18, Dec 19-31, Jan 1-31,  Feb 1-31, Mar 1-31, Apr 1-30 and May 1-31.
*This website is actively being developed and updated with additional information. Information is subject to change.

Smoke Ready Toolbox for Wildfires: Guides, Fact Sheets and Other Resources

The Environmental Protection Agency (EPA) has created a webpage that provides guides, fact sheets, brochures, infographics and web resources for use in learning about the health impacts of wildland fire smoke.

View this wonderful resource here.

Please see below for answers to many frequently asked questions. An additional resource is available here.

There are three categories of air quality data that are available:

  • Routinely collected air quality data from fixed monitors from the Bay Area Air Quality Management District (BAAQMD) and Northern Sonoma County Air Pollution Control District (NSCAPCD).
  • Supplemental air quality data from recently placed mobile monitors. This includes California Air Resources Board monitors placed at Sonoma County schools located near debris sites.
  • Debris site monitoring conducted by US Army Corps of Engineers.

Indoor Air FAQ

Soot or ash inside your home can cause odors that can linger for a long time. You should thoroughly clean those parts of your home with smoke damage. Possessions or parts of your home that have been burned should be discarded. See the answer to “What can I do about the air quality in my home as a result of smoke, soot, or ash?” for more guidance.

During and immediately following the fires are when air quality impacts are the highest. There are steps you can take to prevent nearby burned buildings from affecting your home’s indoor air quality. Take off your shoes and wipe off your pets’ paws to prevent them from tracking ash and soot into your home. Keep doors and windows shut as much as possible. Clean parts of your home with smoke damage (see “What can I do about the air quality in my home as a result of smoke, soot, or ash?”).

Ash and soot will be absorbed into the ground over time and following rainfall. Sonoma County has received a good amount of rainfall since the October fires. At this point, it is unlikely that nearby burned buildings can affect your home’s indoor air quality.

As stated by the California Air Resources Board (CARB), “the most effective way to reduce exposure to indoor pollutants is to first remove sources of pollution or reduce pollutant emissions”. This means thoroughly clean the parts of your home damaged by smoke, ash, and/or soot. We recommend following the American Red Cross “Cleaning Up After a Fire” guidelines, found here. These simple guidelines are applicable for cleaning walls, floors, furniture, garments, dishes, etc. using mild detergent or bleach.

Note, some cleaning products contain chemicals that can cause or worsen asthma or affect indoor air quality. See CDPH’s resources about choosing a safe cleaning product here.

According to CARB, cleaning and ventilation are the best ways to improve indoor air quality and “if these actions do not resolve indoor air quality problems, sensitive individuals may benefit from using a central air filter or a good air cleaner in one or more rooms of the house.”

If you choose to use an indoor air cleaner, you should consult CARB’s list of certified, non-ozone generating, indoor air cleaners here.

CARB recommend that air cleaners that intentionally produce ozone should not be used in the home.

Not necessarily. According to the US EPA, duct cleaning has never been shown to prevent health problems or reduce particles in home indoor air. Learn more here.

Nevertheless, if you are considering hiring a company to clean ducts in your home, consult the US EPA document for advice on choosing a reputable company and other considerations.

This depends on a number of factors, most importantly whether your home was actually damaged by fire. For cleanup of smoke and soot, we recommend trying the cleaning steps above before considering a restoration or cleanup service. We cannot recommend specific remediation companies or contractors. The Contractors State Licensing Board (CSLB) can help consumers find a licensed remediation contractor. The CSLB website includes a number of links (resources) to help consumers chose a reputable contractor.

If you choose to hire a restoration or cleanup service, we recommend caution and careful consideration if the service includes cleaning with chemicals (e.g., ozone, solvents, thermal foggers, etc.). Some of those cleaning materials may create byproducts and linger on household surfaces. The health impacts of these have not been well characterized.

We do not recommend this. Smoke and soot are known to contain toxic substances. However, testing the air in your home will not tell you if, how, or when a chemical may affect your health. It is not possible to draw cause and effect health-related conclusions in these situations. The best way to deal with smoke and soot is to clean your home as described above.

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