The King Fire burning in El Dorado and Placer Counties has prompted Air Pollution Control District officials to issue a health cautionary statement for smoke impacts in San Joaquin, Stanislaus, Merced, Madera, Fresno, Tulare, Kings, and the Valley air basin portion of Kern County.
Officials say the King Fire may continue to bring potentially harmful air to the San Joaquin Valley. Placer and El Dorado County officials have also issued statements that poor air quality conditions exist due to smoke from the King Fire.
The elderly, young children and people with respiratory conditions are advised to avoid exposure or exercise outside when smoke is present. In Reno this week, health officials said the air reached the 'Very Unhealthy' stage Thursday.
Shifting wind direction has sent the smoke to areas of Nevada and California this week.
Health officials say smoke from fires produces fine-particulate matter, which can cause serious health problems including lung disease, asthma attacks and increased risk of heart attacks and stroke.
More than 4,400 firefighters are working to contain the King Fire, which has burned more than 76,000 acres in two counties.