Over 100,000 people advised to stay inside in California

Residents in parts of Southern California face potentially unhealthy levels of air pollution early on Monday morning, according to a live map from AirNow.

The map shows an area of fine particle (PM2.5) pollution in the “unhealthy” category Air Quality Index (AQI) category east of Los Angeles, encompassing portions of cities including Riverside, Corona, San Bernardino and Ontario.

When air quality reaches the “unhealthy” category, the Environmental Protection Agency (EPA) advises that sensitive groups—including young children, older adults and those with certain medical conditions—avoid long or intense outdoor activities and to consider rescheduling or moving activities indoors. The general population is advised to reduce long or intense activities, and to take more breaks during outdoor activities.

Air quality data resource AirNow is a partnership between the EPA, National Oceanic and Atmospheric Administration and other agencies.

The Air Quality Index measures air pollution on a scale from 0 to 301 and above:

0—50 (Green): Good — air quality is satisfactory, and air pollution poses little or no risk.51—100 (Yellow): Moderate — air quality is acceptable. However, there may be a risk for some people, particularly those who are unusually sensitive to air pollution.101—150 (Orange): Unhealthy for sensitive groups — members of sensitive groups may experience health effects. The general public is less likely to be affected.151—200 (Red): Unhealthy — some members of the general public may experience health effects; members of sensitive groups may experience more serious health effects.201—300 (Purple): Very unhealthy — health alert. The risk of health effects is increased for everyone.301 and higher (Maroon): Hazardous — health warning of emergency conditions. Everyone is more likely to be affected.

The South Coast Air Quality Management District (AQMD) has issued a mandatory wood-burning ban through Monday for the South Coast Air Basin, which includes large portions of Los Angeles, Orange, Riverside and San Bernardino Counties with the exception of the High Desert and the Coachella Valley.

According to the agency, such alerts are “mandatory in order to protect public health when levels of fine particle pollution or ozone are forecast to be high anywhere in the South Coast Air Basin.”

Exemptions from the ban include areas above 3,000 feet in elevation, homes that rely on wood as a sole source of heat, and those without natural gas service.

“Particles in smoke can get deep into the lungs and cause health problems (including asthma attacks) and increases in emergency room visits and hospitalizations,” the South Coast AQMD said in the alert.