The Mendocino County Office of Education in partnership with our Mendocino County School Districts, have established guidelines for school cancellations or suspension of school-related activities due to poor air quality. This protocol has been established in order to protect student and staff health in light of ongoing smokey conditions caused by wildfires throughout the Pacific Northwest. We are currently in the process of installing air quality monitors in all our school district sites. However, in the meantime, we are asking our school districts to perform a visual test, as well as refer to purpleair.com or airnow.gov to determine air quality conditions for their schools. The following guidelines utilize the Environmental Protection Agency’s Air Quality Index (AQI) numbers as well as guidance from the Centers for Disease Control (CDC). Under these guidelines, districts will:

• Consult the website purpleair.com (airnow.gov or visual guide will be used until sensors are installed) at 5:00 am on the day of the suspected closure
• Consider canceling classes at an AQI of 275 or higher
• Report closures to affected families through pre-established channels

These guidelines are effective immediately and apply to all Mendocino County public school districts.

Why the level 275?

Although an AQI level of 301 is the threshold for “Hazardous” air quality for adults, since students are ages 4-18, a lower level was considered appropriate. This came with guidance from the CDC with the understanding that air quality tends to worsen as the day progresses.

Why decide at 5:00 am?

It is difficult to make an accurate prediction of the AQI the night before. These major decisions must be made with the best information available and that information is typically not available until the morning.

Generally, we believe students are in a safer air quality environment when they are in school. This is because schools typically use filtered air systems while many homes may not have this capability. Additionally, students at school have greater opportunities for indoor activity. While these standards provide a baseline for districts when considering the cancellation of classes, it is ultimately each district’s decision to determine what is best for their students and staff.

MCOE will continue to work alongside our school districts as well as state and local public health agencies to ensure that all students and staff within Mendocino County are kept safe and healthy.