Air quality dropped considerably after hundreds of Fourth of July firework shows lit up skies across the Los Angeles region Monday, and remained at unhealthy levels into Tuesday morning for many areas.
The South Coast Air Quality Management District issued a particulate advisory through Tuesday for much of Southern California, from Los Angeles and into the Coachella Valley, because of fireworks, which emit high levels of particulate matter and metal air pollutants.
“Fine particulate matter levels on July 4th and July 5th are typically among the worst days of the year in the South Coast Air Basin,” the advisory said. “The smoke and combustion products from fireworks add to the fine particles already present in the basin that are primarily caused by motor vehicles, as well as fugitive dust and industrial emissions.”
The pollution from fireworks last Fourth of July caused the second-worst air quality measures on record from the holiday.
Areas outside the city of Los Angeles — from Thousand Oaks to El Monte and Riverside — remain in unhealthy air quality levels Tuesday morning, according to the South Coast Air Quality Management District. Parts of downtown L.A. are still considered unhealthy for sensitive groups, but most of South L.A. had recovered from the fireworks pollution as of 10 a.m. Tuesday.
For most of Monday, measurements on the U.S. Air Quality Index Scale hovered around moderate or good in the Central Los Angeles area, but only through 9 p.m. Starting then — just after most firework shows — air quality metrics worsened, dropping to “unhealthy for sensitive groups,” and by 10 p.m., the measurement dropped two index levels into “very unhealthy,” data shows.
That level remained for the next three hours, improving only to “unhealthy” for most of Tuesday morning — a category still three levels worse than Monday’s pre-evening fireworks, according to the Air Quality Index.
According to the index during the same time frame, north Orange County saw a similar shift, moving from “good” or “moderate” air quality before 10 p.m., into “unhealthy” or “very unhealthy.” But by 4 a.m. Tuesday, that area’s air quality had recovered back to “moderate,” data showed.
The west San Gabriel Valley region followed a similar trend during the evening’s fireworks, moving from relatively good air quality measurements Monday evening into “unhealthy” or “very unhealthy” by late Monday and into Tuesday.
But some areas not far from the coast, such as Culver City, didn’t record any drastic changes in air quality, remaining at healthy levels throughout Monday evening and into Tuesday. Others more to the south, including Long Beach and Hermosa Beach, recovered quickly from the firework shows, though those areas still recorded “unhealthy” levels of air soon after 9 p.m. By Tuesday morning, most of the coast and southern L.A. were back to healthy or moderate air quality levels.
The South Coast Air Quality Management District warned residents that breathing in fine particulate matter can lead to “cardiovascular and respiratory health effects,” such as coughing, difficulty breathing, decreased lung function or even heart attacks.
The region’s air advisory is set to expire by Wednesday.