Fairfield County has some of the worst ozone pollution in the United States and the worst east of the Mississippi River.

This matters because ozone pollution means smog on hot summer days. Breathing that smog means damaged lungs and trouble breathing.

“It’s been likened to having a sunburn in your lungs,” said Paul Billings, the American Lung Associations’ senior vice president for public policy, of the harm smog does.

Dr. Amy Ahasic, chief of pulmonary medicine at Norwalk Hospital — which with Danbury and New Milford hospitals are now part of seven-hospital Nuvance Health system — said there’s well-accepted medical evidence that inhaling microscopic particulate matter can cause permanent lung damage.

“Big particles get stuck in your nose,” she said. “The fine particles go deeper.”

California has set the strictest standards in the country to limit auto emissions — the major cause of ozone and smog. This month, the Trump Administration announced plans to strip California of its ability to set its own emission standards.

Connecticut is now part of the lawsuit to stop this move.

It matters. It’s not a fight over cars. It’s one over climate change and public health.

And given the stakes involved, it’s one that’s perplexing.

“I don’t understand it,” Nancy Alderman of Environment and Human Health, a state environmental advocacy group, said of the Trump administration’s move. “It hurts the planet. It hurts human health. And it hurts the auto industry.”

“States like Connecticut, which are challenged by air pollution problems, have always looked to California,” said Tracy Babbidge, chief of the state Department of Energy and Environmental Protection’s Bureau of Air Management. To wipe the California standards off the books “is so problematic for us,” she said.

California’s half-century lead on fighting air pollution was born of necessity — it had, and still has, some of the worst air pollution in the country.

In 1959 it set up the first regulations to study motor vehicles and their pollution and began regulating auto exhaust emissions in 1966.

In 1970, when the federal Clean Air Act became law, California had already set its air pollution standards stricter than the newly passed federal regulations. So the federal government granted it a waiver, allowing the state standards to remain in place.

Other states can’t do this. But they can adopt the controls California has put into place.

In 2004 Connecticut became one of the first states to adopt the 2002 California Clean Car standards. Currently, 12 other states and the District of Columbia have adopted them as well. Population size matters — the people in those states comprise 40 percent of the national auto market.

As part of the Obama Administration’s bailout of the auto industry, it made those California Clean Car standards the national standard, requiring the auto industry to build fleets of cars that would average 54 miles per gallon by 2025.

Greater fuel efficiency means cars burn less fossil fuels and cleaner air. It’s estimated the Obama Administration’s standards would remove 570 million metric tons of greenhouse gases from the atmosphere by 2030.

Automakers, wanting to make cars for one national market, are willing to abide by those standards. Four major auto companies — Ford, BMW, Honda and Volkswagen of America — have largely agreed to do so.

The Trump Administration — seemingly opposed to all things Obama and California — would slow the auto efficiency standards to 37 miles per gallon.

Those national efficiency standards matter to Connecticut because it’s a victim of its geography. Prevailing winds carry air pollution up the East Coast and from the Midwest. Much of the state’s air pollution has out-of-state origins.

Motor vehicle pollution is, by far, the leading cause of the state’s air pollution, with 65 percent of the smog-producing pollutants and 40 percent of all its carbon pollution coming from tailpipes.

The DEEP’s Babbidge said the state’s air pollution is worst along its interstate highways, where there’s the most traffic congestion.

Summer sun and hot weather mix with tailpipe emissions to create unhealthy smog.

“We’ve had 20 days this year when we failed to meet the national standards for smog,” Babbidge said.

Climate change’s hotter summers could mean more smog for the state and more health problems.

Ahasic, of Norwalk Hospital, said there’s obvious proof that improving air quality can improve human health. The federal government banned lead in gasoline in 1990. Lead levels in children plummeted. They were no longer poisoned by the air they breathed.

“Think about lead in gas,” she said.

Connecticut Media Group