Air pollution has been linked to more than 30,000 deaths in the United States in a single year — with low income areas the hardest hit, a new study suggests.

The research from the Imperial College London estimates particle pollution emitted by cars and power plants may have been responsible for 30,369 deaths in 2015 — the most recent year air quality data was available.

The study, published Wednesday in the journal PLOS Medicine, established a link between cardio-respiratory diseases and excess particulate matter pollution — tiny, inhalable particles that can worsen certain diseases when they enter the blood stream.

Researchers found traffic-logged Los Angeles was the worst city for life expectancy loss due to particle pollution — followed by states such as Arkansas, Oklahoma and Alabama.

The study also found loss of life expectancy from air pollution as worst in low income areas.

Researchers said this “inequality in mortality burden” occurred because people with lower incomes had higher rates of preexisting medical conditions.

“I think the big conclusion is that lowering the limits of air pollution could delay in the US, all together, tens of thousands of deaths each year,” Majid Ezzati, the study’s lead author and a professor of global environmental health told CNN.

Researchers analyzed air quality trends between 2015 and 1999 at over 750 monitoring stations and compared them with death records for cardiovascular-related diseases.

Those deaths came as most counties in the US complied with federal air quality standards, suggesting more stringent regulations are needed, researchers said.

While particulate matter decreased over the past two decades, the study said anything above the lowest observed concentration was responsible for tens of thousands of deaths.

“If we make the current standards more stringent,” Ezzati told CNN, “there is a high likelihood we will delay tens of thousands of deaths each year and people will live longer as a result of it.”