July 28, 2006 – Yreka – Siskiyou County Public Health Officer, David J. Herfindahl, M.D. advises residents throughout Siskiyou County to be aware that air quality may be extremely poor in many areas due to severe smoke. In areas with visibility less than 2 miles, residents are advised to remain indoors and refrain from physical exertion. Residents with lung or heart disease, and the elderly are advised to leave areas where levels of particulate matter are high. The attached index will assist in assessing the air quality based on the visibility in your area.
To assess visibility:
Face away from the sun.
Determine visibility range by looking for targets that are at known distances (miles).
The visible range is the point where even high-contrast objects disappear.
After determining visibility in miles use the Wildfire Smoke Visibility Index (linked below) to assess air quality.