Alejandra Burunda

Right.

The Environmental Protection Agency under the Trump administration has announced its intention to weaken regulations that have helped clean up American air.

Alejandra Burunda, NPR News.

For years, the EPA has compared the costs for an industry to clean up pollution to the benefits to Americans' health.

For example, cleaning up pollution from soot keeps people from getting asthma or having a heart attack or even dying.

And EPA has put a dollar value on that better health.

That's changing.

EPA now says those dollar estimates of savings are too uncertain to use.

And that could make it easier to roll back air protection rules, according to New York University environmental law expert Richard Gervais.

He says rollbacks can look good.

Air pollution regulations have saved hundreds of thousands of lives each year, according to previous EPA estimates.

Alejandra Burunda, NPR News.

Cities like London and Stockholm tried congestion pricing first and saw air quality get better.

But the air pollution drop of 22% in New York City may be one of the biggest ever seen.

The study was published in the journal NPJ Clean Air.

It looked at levels of pollution called PM2.5.

Those are tiny particles about 30 times smaller than the width of human hair.

Cars and trucks burning gas or diesel are a major source.

NPM 2.5 air pollution can worsen many different health problems, from breathing problems like asthma to brain diseases like dementia.

But it'll still take a while to see if New Yorkers' health improves from the cleaner air.