A regional air quality alert was issued for much of Southern California as harmful levels of fine particle pollution spread across the region following Fourth of July fireworks and active wildfires in nearby mountain areas.
The South Coast Air Quality Management District (South Coast AQMD) announced the alert on Friday, July 4, warning that elevated pollution levels would persist through Saturday night, July 5, due to smoke from Independence Day celebrations and wildfires in parts of Los Angeles County and beyond.
The alert applied to most of Los Angeles and Orange Counties, the Inland Empire, Santa Clarita, and the San Gabriel and San Bernardino Mountains. Officials said pollution levels could vary by time and location depending on emissions and local weather conditions.
Smoke from fireworks was expected to affect the region from 5:00 p.m. Friday through 11:59 p.m. Saturday. Wildfire smoke in mountain areas was projected to impact air quality from midnight Friday through 10:00 p.m. Saturday.
Health officials warned that fine particle pollution can penetrate deep into the lungs and may lead to serious health problems, including asthma attacks, bronchitis, heart attacks, and difficulty breathing. While anyone can be affected, sensitive groups are at higher risk.
Residents were urged to monitor the Air Quality Index (AQI) and adjust their activities accordingly:
- When AQI reaches the “Unhealthy for Sensitive Groups” (orange) level, vulnerable individuals should limit prolonged or strenuous outdoor activity.
- At the “Unhealthy” (red) level, everyone may experience health effects, and sensitive groups should avoid extended time outdoors.
- When levels are “Very Unhealthy” (purple), sensitive groups should avoid all outdoor activity, and others should limit outdoor exposure.
- At the “Hazardous” (maroon) level, all individuals are advised to stay indoors and avoid outdoor physical activity entirely.
To reduce indoor exposure, officials recommended keeping windows and doors closed, using air conditioners or air purifiers, and avoiding the use of fireplaces, candles, incense, or gasoline-powered equipment. If possible, residents should avoid using swamp coolers or whole house fans that draw in outside air.
Residents in the Los Angeles Basin, San Bernardino Valley, San Gabriel and San Bernardino Mountains, Orange County, and Riverside County can check real-time air quality levels and forecasts by visiting the South Coast AQMD website at www.aqmd.gov or by downloading the mobile app at www.aqmd.gov/mobileapp.
For those in the Antelope Valley, updates are available at www.avaqmd.ca.gov. In the Mojave Desert, current conditions and advisories can be found at www.mdaqmd.ca.gov.
