SAN FRANCISCO (CBS SF/KPIX) – The wildfires raging across Northern California have sent a blanket of unhealthy smoke over Bay Area.

The Bay Area Air Quality Management District issued Spare the Air alerts through Sunday because of the smoke from fires sparked by lightning, last weekend.

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The air district had already issued alerts through Wednesday, then extended it through this weekend because of elevated particulate pollution levels caused by the wildfires.

One woman told KPIX, “The sun was a big red dot in the sky and there was ash over everything.”

Masks may help residents stay healthy when they go outdoors.

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“If you are outside in an area with particulate matter, wear a mask- N95 is especially helpful,” said Dr. David Cornfield with Stanford Children’s Health.

Related: Bay Area Wildfires

The Peninsula, Santa Clara Valley and Livermore Valley are expected to see the heaviest impacts from the smoke pollution, but impacts are possible throughout the Bay Area, according to the air district.

On Spare the Air days, it is illegal for people to use fireplaces, wood stoves, pellet stoves, outdoor fire pits or other wood-burning devices.

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