1. Mid of women with masks on sifting through ashes of debris of burnt home, pull out
2. Wide of people sifting through debris with masks on
3. Close-up of women with masks on
4. Close-up of debris being sifted
5. Mid of two women walking through fire damaged neighbourhood with masks on
6. SOUNDBITE: (English) Christina Durvis, San Diego resident:
"This is the first time we have really looked up close, so I can't really process how I feel about the smoke, because of the visual images. But it smells horrible and I can feel it in my lungs even with my mask."
7. SOUNDBITE: (English) Laurie Norcross, San Diego resident:
"It's bad, it's bad, but it seems like it's not getting much better at this point. It still feels pretty consistent, it's hard to take a deep breath."
8. Mid of doctor showing how smoke affects your lungs
9. Various shots of hospital
10. SOUNDBITE: (English) Dr Timothy Morris, Service chief for pulmonary medicine at UCSD Medical Centre:
"It can make you a little short of breath. It can make you start to cough or even make you start to wheeze. Now for a normal healthy person, that is usually a minor nuisance. For somebody who has a pre-existing lung condition, it can actually be quite dangerous."
11. Mid of men going through debris with masks on
12. Various of men working with masks on sifting through debris of burnt house
As the wildfires in the US state of California die down and residents return home, lingering dust and soot-laden air are making it difficult for many to breathe even a sigh of relief.
Air quality remained poor in the central San Bernardino Mountains and parts of the San Bernardino Valley as well as swaths of Orange and Riverside Counties.
In San Diego County, where only one of four major fires was more than 50 percent contained, the air quality was especially bad on Friday.
"It's bad, it's bad," said Laurie Norcross, who was helping to sift through the debris at a friend's burnt out home. "It seems like it's not getting much better at this point, it feels pretty consistent, it's hard to take a deep breath."
Satellite pictures continued to show a thick haze of smoke hanging over the entire region, affecting schools, events and the health of residents all over Southern California.
Residents staying in areas with bad air were advised to avoid exerting themselves both indoors and outside.
Children and those with heart and respiratory conditions were urged to stay indoors with the windows and doors closed and air conditioners on.
One of the biggest health threats with fires are the fine particles that are not visible to the naked eye.
These particles can get into the lungs and make breathing an even greater struggle for people with asthma, bronchitis and emphysema.
Miles from any of the fires, smoke and dust from surrounding areas continued to hang like a heavy fog over the port city of Long Beach, making the sun appear a deep orange.
In San Diego, where fires still raged, the University of California San Diego Medical Centre saw an increase in patients coming in with breathing troubles they believe were related to air pollution, but they didn't have statistics available, said spokeswoman Jackie Carr.
"It can make you a little short of breath," said Dr Timothy Morris, the service chief for pulmonary medicine at UCSD Medical Centre.
"For a normal healthy person, that is usually a minor nuisance, for someone who has a pre-existing lung condition, it can actually be quite dangerous," he added.