California Summer Weather Brings 'Very Unhealthy' Smog

cali smog
The skyline of downtown Los Angeles is seen through a layer of smog from a rooftop in Hollywood on May 31, 2006. California's blistering heat wave may cause very unhealthy levels of smog, according to reports on June 16. Fred Prouser/REUTERS

California's blistering heat wave could produce "very unhealthy" levels of smog as temperatures continue to rise across the southern region of the state, officials warned Friday. A statement released by the South Coast Air Quality Management District (AQMD) said ozone levels are expected to reach "unhealthy to very unhealthy" levels in areas including the Santa Clarita, San Fernando and San Gabriel valleys, and in the San Bernardino and San Gabriel mountains.

Areas in Southern California that are already dealing with air pollution are expected to see the highest levels of ozone, the gas in smog that can lead to respiratory and lung ailments. The sweltering temperatures can cook up atmospheric inversions, causing pollution to stay trapped near the ground, which "may cause unusually high and persistent levels of poor air quality," the district said.

Some of the areas listed in the warning, particularly cities located near the valleys and deserts, are expected to see temperatures well above 100 degrees on Friday and Saturday, according to the Los Angeles Times. Death Valley could see temperatures as high as 122 degrees by Saturday.

A spokesman for the AQMD noted the current heat wave marks the first time Californians across several regions of the state may encounter very high levels of smog "all at once."

Smog levels in California have increased in recent years, leading to the deaths of more than 1,300 residents on average each year, according to the American Thoracic Society's 2016 Health of the Air Report. In 2016 alone, Southern California logged 132 days of bad air, with ozone levels reaching the highest levels the region had seen since 2009.

The AQMD recently submitted a 5,000-page proposal on improving California's air quality. Among the lengthy list of emissions plans, the group called for various refineries, ports and warehouses to implement tougher environmental standards. The group also requested nearly $15 billion to start additional programs to encourage pollution cleanup over the next 15 years.