Sacramento-area residents will see a worsening of their air quality this evening due to the effects of the Sand fire that has burned more than 4,000 acres in El Dorado and Amador counties.
A high-pressure weather system will bring smoke from the fire into areas west of the timber and grass fire – with smoke visiting the Sacramento region in the early evening and also early Sunday morning, said Drew Peterson, a meteorologist with the National Weather Service.
That means that residents – especially those with asthma and respiratory issues – will have to take measures in the evening if they want to avoid breathing smoke that comes into the Sacramento Valley.
Typically, when fires burn in similar conditions as the Sand fire, the smoke plume rises as a column in the afternoon and early evening, then descends through the early morning hours and drains into the valley, Peterson said.
“Today, as the day progresses, we’ll see the smoke column rise and the cycle will continue until the wind patterns shift, or until they’re able to contain the fire,” he said.
At present, the fire is 20 percent contained.
No major shift in wind weather patterns are due for area tonight or Sunday, Peterson said.
Wildfire and other fire smoke brings with it a complex mixture of carbon dioxide, water vapor, carbon monoxide and particulate matter known to affect those with asthma and other respiratory conditions. Particulate matter is the most troublesome, especially small particulate matter, which settles deep in the lungs.
A UC Davis study released last year established that there are possible implications for health when humans are exposed to wildfire smoke. That study, conducted by UC Davis scientists and the California Air Resources Board, found that rhesus macaque monkeys born at the university’s Primate Research Center in the summer of 2008 – an unusually intense fire season – had depressed immune systems compared with those born a year later.
For those that have issues with worsening air quality the key will be closing windows, Peterson said.
“People in places like Plymouth and Ione, that are near the fire, they may want to begin to closing their windows in the evening,” Peterson said. “For people in the Sacramento area, they need to close windows before they go to bed at night.”
“It’s deceiving in that during the evening people think the air quality might seem better, but the problem is that smoke descends at that time, and that is when it will move into the valley,” he said.
If people decide to run air conditioning units at night, “they should make sure they are recirculating the air from inside and not pulling in any air from outside,” Peterson said. “If they do not have that option, then it might be best to turn their air conditioning off at night.
Most air conditioning systems are made to recirculate indoor air. However, some systems may have both outdoor air and recirculate settings. Those that have such systems should change their setting to “recirculate.”
The combination of fire smoke and temperatures greater than 100 degrees forecast for the region today and Sunday has prompted the Sacramento Air Quality Management District to issue a “Spare The Air” alert for Sunday. The district is expecting unhealthy ozone levels to continue through Monday.