The Northern Sierra Air Quality Management District and the Public Health Department of Nevada County are issuing a Joint Air Quality Health Advisory due to smoke impacts from the Mosquito Fire in Placer and El Dorado Counties, CA near Oxbow Reservoir.  Smoke impacts could result in air quality conditions in the Very Unhealthy to Hazardous ranges throughout the day.  Air quality conditions change rapidly, and smoke may be intermittent and affect different areas dependent upon wind direction and time of day.  

Poor air quality has the potential to cause negative health impacts, particularly for sensitive groups and when exposure is prolonged.  Exposure to elevated PM2.5 (fine particulate matter in smoke) concentrations can result in eye and throat irritation, headaches, nausea, shortness of breath, congestion, coughing, impaired lung function and chest pain, especially among sensitive individuals such as the elderly, children, people with asthma, people with heart or lung conditions, pregnant women and anyone who is exercising or working hard outdoors. 

If you smell or see smoke around you, the following actions are recommended:

  • Minimize outdoor activities even if you are considered healthy;
  • Stay indoors with doors and windows closed as much as possible; run the air conditioner on the “recirculate” setting if that is an option;
  • People with asthma should follow their personal asthma management plan;
  • People with heart disease, respiratory conditions or chronic health issues should stay indoors;
  • Contact your doctor if you have any symptoms of cough, shortness of breath, chest pain, or severe fatigue;
  • Snug fitting N95 masks are effective in protecting the wearer from smoke particles. Re-use of N95 masks may reduce effectiveness and make breathing more difficult. Surgical and cloth masks are not effective in protecting against smoke damage to the lungs due to the very small particle size.

Near real-time air quality conditions for the Northern Sierra Air Quality Management District may be found at (click on your location of interest under “Local Air Quality”).  As you view the most recent data, consider that conditions can change rapidly due to wind shifts; it is important to monitor the smoke throughout the day and make plans accordingly.  The smoke may be visible in satellite imagery, available via (near the bottom of the page).

Additional information about air quality can be found on the following website:

Smoke mapping can be found at: