Citizens in Sacramento, California, spent 39 days in 2017 breathing air with unhealthily high ozone levels—a frequency that far exceeds the American Lung Association's "failing" parameter of just three days per year.
Sacramento is one of eight California cities to rank in the top 10 for ozone pollution in the ALA's annual State of the Air Report, released in April. It's now the fifth-most polluted city in the nation, and the fastest-growing large city in California.
"We're in a valley, so air pollution has nowhere to escape," says Thomas Hall, a communications specialist at the Sacramento Metropolitan Air Quality Management District. "In the summer months, ground-level ozone or smog is our primary concern.
It is this concave topography, coupled with the city's rising population, which makes Sacramento a constant on the ALA's air reports—despite the state's best efforts.
What's worse, Sacramento's topography and pollution levels are not so different from other major valley-based metropolitan areas in the state. In fact, all eight of California's most polluted cities are located in valleys; the San Joaquin Valley alone contains four.
Though wildfires and other environmental phenomena contribute to California's pollution problem, the biggest culprit is auto emissions—84 percent of the state's ozone-forming emission sources come from automobiles.
"What we really need to do here in Sacramento is reduce emissions for mobile sources," Hall says. "We need zero emission vehicles, carpooling, transit, all that stuff."
California already has some of the strictest regulations in the country. It is the only state permitted to issue its own emissions standards under the 1970 Clean Air Act, as long as they are at least as strict as the Environmental Protection Agency's standards.
Even if California adheres to its current auto emissions standards, population growth presents another challenge for reducing pollution levels. A report by the California Department of Finance reveals that, of the state's 10 largest cities, Sacramento had the largest percentage gain in population (1.43 percent), with San Diego closely following at 1.42 percent growth. Los Angeles, the most polluted city in the country, continues to grow, adding to a population of over four million.
"Sacramento has been growing for a long time," Hall says. "We know that. We live here, we made this our home, and we want to ensure that we can protect air quality for everyone." Despite air quality specialists' best intentions, however, the Trump administration's new efforts to roll back emissions restrictions could wreak havoc on an already polluted, quickly growing state.
However, the fact that even California's strict emissions standards cannot prevent major pollution suggests that the state has a long way to go to achieve safer air for its citizens.
"We've seen significant improvement in air quality since the 1990s, but in a lot of California cities, improvement has stalled, and we've had backsliding," says Bill Magavern, the policy director at the California Coalition for Clean Air, a non-profit organization dedicated to improving California air quality.
In 2012, when President Barack Obama introduced a comprehensive set of standards on greenhouse gas emissions and fuel economy, he set the goal of doubling the average fuel economy of new cars and light trucks by the year 2025. California agreed to adhere to these new federal standards.
Unfortunately for California, that could soon become much more difficult.
Last month, the EPA moved forward with a plan to roll back the Obama administration's standards, saying they were too stringent. EPA Administrator Scott Pruitt did not specify what limits would be put in place, saying the EPA and the National Highway Traffic Safety Administration would establish a national standard that "allows auto manufacturers to make cars that people both want and can afford."
Automakers can expect, however, to see standards less extreme than the previous goal of producing car fleets that averaged over 50 miles per gallon by 2025. Automakers had already taken this goal into consideration in production plans.
"We are concerned about what [the EPA's rollbacks] would do to the clean vehicle market," Hall says. "California has made a lot of progress on clean cars and clean trucks because automakers have invested in development and marketing on national standards. A rollback would waste a lot of effort and slow the process down when we really need to be speeding up the rate of adaption to emissions standards."
Indeed, major automakers like Ford have expressed enthusiasm for developing the clean car market—or at the very least, adhering to the standards that had already been set instead of adapting to the EPA's new demands.
"I think our emissions standards right now are great," says Jose Orozco, a service manager at a Ford dealership in Sacramento. "I don't see why we wouldn't be able to meet those emissions standards [set for 2025]."
California lawmakers also acutely felt the impact of the EPA's new rollback decision and decided to take action.
Last week, a coalition led by California sued the Trump administration over its plans to roll back the state's strict car emissions standards.
The lawsuit, headed by California and its coalition of 16 states and the District of Columbia, represents an important step in California's ongoing battle with the Trump administration over climate change regulations—the challenge marks California's 10th lawsuit against the EPA and its 32nd since Trump took office.
With the high levels of pollution already present in many California cities, air quality experts emphasize the need for California to keep its ability to promote better air quality for their citizens.
"The South Coast district is seeing more violations of ozone standards, especially in L.A., Long Beach, Riverside, and San Bernadino counties," Magavern says. "We need to be doing more at all levels of government to reduce pollution."