CALIFORNIA—Current air quality data from South Coast Air Quality Management District (AQMD) showed that ozone pollution marked highest in Southern California since 2003 and the highest in downtown L.A. since 1994 on Sunday, September 6.
The Los Angeles Times reported that on September 6, the eight-hour average ozone level in downtown L.A. was 118 ppb, “very unhealthy” on the Air Quality Index, which means “Everyone may begin to experience health effects when AQI values are between 151 and 200. Members of sensitive groups may experience more serious health effects.” Federal standard of ozone level is 70 ppb.
Air Quality Forecast (Sun. 9/6): https://t.co/szsyGAFunD
🏖 Coastal: Moderate -to- Unhealthy
🏙 LA: Moderate -to- Very Unhealthy
🌅 OC: Unhealthy for Sens. Gr. -to- Unhealthy
🌄 Inland Empire: Unhealthy for Sens. Gr. -to- Very Unhealthy
🌴 Coachella Val.: Unhealthy for Sens. Gr. pic.twitter.com/kqYGp2JzjR
— South Coast AQMD (@SouthCoastAQMD) September 6, 2020
Downtown L.A. air monitoring station located on North Main Street in Chinatown read so much higher than normal that the data was not published online immediately and an additional, manual quality control check was conducted in order to avoid releasing wrong data, the L.A. Times said.
After the validation, South Coast AQMD confirmed that the extremely high figures were not caused by instruments’ problems. “The value for noon on Sunday has been reviewed and is preliminarily valid at 185 ppb,” South Coast AQMD spokeswoman Nahal Mogharabi said to the L.A. Times.
Temperatures in Los Angeles County exceeded 120 degrees on September 6, due to a high-pressure system that caught polluted air close to the ground. Extreme heat and weak wind makes pollution stay in the air, which results in high ozone levels, according to South Coast AQMD.
Rising temperatures increase the speed of the photochemical reactions that generate ozone gas, which makes it difficult to control smog. Wildfires are growing more intense with high temperature, so it also causes smog pollution. “The combination of a major wildfire and extreme heat can really send ozone levels through the roof,” the L.A. Times introduced a comment by Yifang Zhu, a professor of environmental health sciences at UCLA Fielding School of Public Health.
South Coast AQMD advises the public to save energy use to control heat wave; set thermostats to 78 degrees or above between 3 p.m. to 10p.m., refrain from using major appliances between 3 p.m. to 10p.m., turn off unnecessary lights, keep windows and doors closed, and charge electric cars after 9 p.m.