Where greenhouse gases come from
Sacramento is among the most polluted cities in the United States.
In a report by the American Lung Association released Wednesday, Sacramento is fifth in the nation for ozone pollution, jumping up three spots from last year. Los Angeles and three Central Valley cities outrank Sacramento for pollution and average numbers of bad ozone days.
"Ozone pollution is a corrosive gas," said Bonnie Holmes-Gen, director for air quality and climate change with the American Lung Association in California. "It actually causes burns on lung tissue, like a bad sunburn ... It can cause long-term health problems. It can worsen asthma symptoms and contributes to heart attacks and early death."
Sacramento's air quality has worsened primarily because of heat waves and emissions from cars, buses and freight vehicles, she said.
Parts of the Sacramento region have seen bad ozone days increase by an average of nine days, bringing the total to nearly a month, she said.
Alberto Ayala, executive director of the Sacramento Metropolitan Air Quality Management District, questioned the grading system.
“I would note that this report includes data from as far back as 2014 in its grading system and constitutes a simplified examination of what is a really complex issue," he said in a statement. "The grades aren’t measuring air quality in the way that federal methodology requires – it’s an apples and oranges comparison. California’s air quality reality is much more complex than what a letter grade can explain."
Ozone pollution puts people with chronic respiratory and cardiovascular disease at risk, according to the report. In Sacramento, there are nearly 46,000 children and 155,000 adults with asthma. Children and seniors are among the most vulnerable populations for developing complications from breathing bad air.
"It’s a relatively stagnant place so any pollutants we emit just hang out and interact to make ozone," said Anthony Wexler, director of UC Davis Air Quality Research Center. "Most of these bad ozone days occur in the summertime when the sun is pretty hot. The sun is what makes the reaction go and turns those compounds into ozone."
The air pollution isn't just limited to Sacramento. Placer, El Dorado, Nevada and Sutter counties also received "F" grades for having more than three unhealthy air days per year, according to the regional summary from the report. Yolo County received a "D."
"(The air pollution) concentrates up against the foothills so that means Placer, El Dorado and Sutter counties are experiencing some the highest levels of ozone in our region," Holmes-Gen said.
To reduce the amount of pollutants in the air, Sacramento Region Spare the Air suggests people drive less, use electric power tools instead of gas-powered tools and fill up their cars after the sun goes down.
"These pollutants are not just a nuisance, they represent a public health crisis in California and especially in our region," Holmes-Gen said.
Molly Sullivan: 916-321-1176, @SullivanMollyM