LONG BEACH, Calif. — The Long Beach and Los Angeles Harbor area is one of the country’s most polluted regions, according to the American Lung Association.

Elizabeth Reyes was born and raised in Long Beach. Her mother was hospitalized for breathing problems and now relies on an inhaler.

The wall behind their home has been there since she was born. Parts of it tower over Reyes. She’s learned though in her 23 years that it doesn’t keep everything out.

“It’s difficult when you want to get a good gasp of air and the air’s not that great,” said Reyes.

There’s not a lot you can do to avoid pollution from the nearby rail yard and refineries except be prepared.

That’s where Ray Cheung, the executive director of SmartAirLA, comes in. Cheung created an air quality tracker that spits out a score from zero to five every day. The higher the number, the worse conditions are for people who have trouble breathing. His work focuses on the troubled harbor area.

“These are communities that have been exploited and promises not kept, so they’re going to come with, I wouldn’t say distrust, but skepticism,” said Cheung.

But change is underway. The South Coast Air Quality Management District recently ruled that certain large warehouses must reduce nitrogen oxide and diesel particulate matter emissions. Given these places are a key destination for big rigs, it makes sense that there are six such warehouses at the port complex and about 200 in the area nearby.

Work has been going on for a while to phase out older, more polluting trucks in favor of natural gas-powered and hydrogen-powered electric vehicles. From the port’s side of things, it looks like it’s working. Emissions levels are dropping.

Residents like Reyes remain unconvinced.

“Have I seen a change in a good way? Not so much, but I mean I wish I could see a change,” Reyes said.

Reyes plans to start graduate school soon at California State University, Long Beach, which means she’ll definitely stay close to home for a couple more years, but visiting family in Arizona was eye-opening.

“Over there, during the night, if you look up you can actually see the stars, which is a complete change,” said Reyes.

Several sources agree the trucking and freeway traffic contribute the most pollution in this region. Reyes and her family live less than a mile from the 710, which is the main outbound artery for the ports.

Expanding the 710 has been talked about for years, but federal environmental regulators recently found that the $6 billion proposal to grow the freeway might violate Clean Air Act standards.