Today is terrible with Smoke again.
Because of the wildfires in Northern California, area residents were breathing unhealthy air Tuesday and conditions are expected to be the same today.
The smoke drifting into the valley caused air quality officials to update the air pollution rating from unhealthy for sensitive groups to unhealthy for everyone in Stanislaus, San Joaquin and Merced counties.
When the pollution is this bad, everyone may begin to experience health effects, and sensitive groups, including senior citizens, young children and people with chronic health conditions, may experience more serious health problems, according to health experts.
Merced County had the worst air pollution in the eight-county area covered by the San Joaquin Valley Air Pollution Control District. The level of air pollution was third-highest in Stanislaus County.
The wildfires are creating two types of air pollution. One is the tiny particles that are so small they can get deep into the lungs. The fires also are sending emissions into the air that react with sunlight to form ozone. Excessive ozone has a corrosive effect on the lungs.
"Unfortunately, we have also seen our ozone levels perk up in the last few days," said Shawn Ferreria, a senior air quality specialist for the valley air district. Merced County has recorded the highest ozone readings in the valley this week.
The valley is getting smoke from all directions because of fires in Tuolumne, Calaveras, Mariposa, Monterey, Napa, Solano and other counties in Northern California, plus a grass fire that has burned 800 acres north of Grayson in western Stanislaus County. The 10 to 15 mph wind forecast for today won't rid the valley of smoke; the conditions are expected to persist until the fires are put out, Ferreria said.
To make matters worse, a ridge of high pressure building over California is expected to bring warmer weather and stagnant air Friday and through the weekend, Ferreria said. That could keep the air quality in the unhealthy range and could push it toward "very unhealthy" in some parts of the valley, he said.
Very unhealthy air has occurred a few times in the southern part of the valley since the air district was created in 1990. It triggers a health warning that everyone may experience more serious health effects.
Exposure to particle pollution can cause serious health problems by aggravating lung disease, causing asthma attacks and acute bronchitis, and increasing the risk of respiratory infections. Short-term exposure to particle pollution has been linked to heart attacks and arrhythmia, according to the Environmental Protection Agency.
Stay inside, reduce activity
Residents are advised to use caution until the smoky conditions are alleviated. Everyone should reduce exposure and strenuous activities, and that advice especially applies to older adults and children.
The valley district uses an air quality index (AQI) to report daily air pollution. It's based on a calculation of five major pollutants: ozone, particles, carbon monoxide, sulfur dioxide and nitrogen oxide.
On Tuesday, Stanislaus County had an air quality index of 176 and the same is forecast for today, mainly because of particle pollution. An AQI from 151 to 200 is considered unhealthy; 201 to 300 is very unhealthy and above 301 is hazardous.
Merced County had an AQI of 187 on Tuesday and 185 is forecast for today. Air district officials said the high AQI in Merced County is partly because of stricter health standards for ozone pollution that went into effect in May.
Health officials have wondered whether the smoky air would send people to emergency rooms with breathing problems or other health issues. But no hospitals have reported an increase in patients.
"The number of people coming in has been consistent for the past few days," said Catherine Larsen, spokeswoman for Memorial Medical Center in Modesto. "Our emergency department has been monitoring it pretty closely because they were concerned with that as well."
Susan Mendieta, a spokeswoman for Oak Valley Hospital District in Oakdale, said she checked with the district's community health centers and the hospital emergency room, and no one reported a spike in patients.
"What we are hoping is that people are heeding the warnings and being cautious, and taking the steps of staying indoors and drinking lots of fluids," she said