The South Coast Air Quality Management District said Tuesday that air quality after this year's Fourth of July festivities was not as bad as last year’s Independence Day, but showed the second highest pollution levels for Independence Day in the last decade.
In a release, the AQMD said the level of fine particulate matter this year remained higher than average Fourth of July celebrations, but was 14% lower than last Fourth of July's levels, which was highest-ever in terms of pollution.
The level of pollution, however, was the worst in the region since the Bobcat Fire last September. Personal "backyard" fireworks and commercial fireworks displays in the region were blamed for the poor air quality.
Officials warned that high levels of fine particulate matter can have negative health effects and lead to cardiovascular and respiratory health problems, such as heart attacks, asthma aggravation, decreased lung function, coughing and difficulty breathing.
The AQMD found "unhealthy" to "hazardous" air in the valley and inland areas, with the highest concentration recorded in the San Bernardino County city of Ontario.
Concentrations of PM2.5 were 70% higher than previous years between 7 p.m. on July 4, 2021 and 7 a.m. the next day in the South Coast Air Basin, which includes Orange County and parts of Los Angeles, Riverside and San Bernardino counties, according to the AQMD.