Air quality in the Los Angeles area is expected to remain unhealthy Saturday as multiple wildfires continue ravaging the region.

The smoke was most directly impacting areas near the Palisades, Eaton and Hurst wildfires, the agency reported. According to AQMD, air quality ranged from "unhealthy for sensitive groups" to "hazardous" on Thursday afternoon in the areas of Pacific Palisades, central and southwestern Los Angeles County and the San Gabriel Valley.

The levels were "unhealthy" in the San Fernando Valley and moderate in Orange County.

Smoke impacts will depend on fire activity, containment efforts and the weather, according to the AQMD.

Wildfire smoke is a mixture of small particles, gases and water vapor -- with the small particles being the primary health concern, the AQMD reported. Those particles can cause burning eyes, a runny nose, scratchy throat, headaches and/or illnesses such as bronchitis

The agency noted that people at higher risk -- including children, the elderly, those with respiratory or heart conditions and people with compromised immune systems -- may experience more severe effects, including difficulty breathing, wheezing, coughing, fatigue and/or chest pain.

"Predicting where ash or soot from a fire will travel, or how winds will impact air quality, is difficult, so it's important for everyone to stay aware of the air quality in your area, make plans, and take action to protect your health and your family's health," Dr. Muntu Davis, L.A. County's health officer, said in a statement. "Smoke and ash can harm everyone, even those who are healthy."

The health department urged people in areas where there is visible smoke or the smell of smoke or unhealthy air quality to avoid unnecessary outdoor exposure and limit physical exertion.

"Children, older adults and people who are pregnant or have other air quality sensitive conditions, such as heart disease, asthma and other chronic respiratory diseases, should follow these recommendations and stay indoors as much as possible even in areas where smoke, soot or ash cannot be seen or there is no smell of smoke," according to the agency. "If your condition worsens, contact your health care provider immediately for medical advice."

Pets can also be affected, the agency reported.

The AQMD also extended a ban on indoor and outdoor wood burning in much of the Southland due to a forecast of high air pollution in the area.

The residential wood-burning ban will be in effect until at least 11:59 p.m. Saturday for all those in the South Coast Air Basin, including the non-desert portions of Los Angeles, Riverside and San Bernardino counties, and all of Orange County.

The order does not apply to mountain communities above 3,000 feet, the Coachella Valley or the high desert, according to the South Coast Air Quality Management District. Homes that rely on wood as a sole source of heat, low-income households and those without natural gas service also are exempt from the requirement.

Residents in the affected areas are reminded that burning wood in their fireplaces or any indoor or outdoor wood-burning device is prohibited, as is burning manufactured fire logs, such as those made from wax or paper.

Fine particles in wood smoke, also known as particulate matter or PM2.5, can get deep into the lungs and cause respiratory problems such as asthma.

For real-time and forecasted air quality information, the AQMD Mobile App can be downloaded at aqmd.gov/mobileapp; information is also available at aqmd.gov/home/air-quality/air-quality-forecasts.