You're listening to Shortwave from NPR.

Hey everyone, Emily Quang here with NPR Health Correspondent, Allison Ophry.

Hey Emily, today on the show we're going to look back at the 9-11 attacks that occurred

20 years ago tomorrow.

Rescue workers today continued pouring through the enormous pile of rubble that sits where the

trade center used to be.

Filling buckets with debris and passing them down a human chain to be carted away.

One problem hampering the work this week has been dust.

And focus on the health impacts of what happened in New York City at the World Trade Center,

where thousands of first responders, including firefighters and rescue workers, were called to

the scene for weeks.

20 years later, researchers have documented an increased incidence of several types of

cancer.

But a new study actually offers some reason for optimism.

As out, first responders appear to be surviving their cancers at significantly higher rates.

Now, the question is why?

You're listening to Shortwave, the Daily Science Podcast from NPR.

So Allison, I grew up in the New York City area and I remember this period,

so clearly, many first responders spent weeks doing rescue and recovery work at the Ground Zero site.

In the aftermath of September 11th, what were they exposed to?

Well, you know, just after the towers collapsed, the air was just filled with smoke, with debris.

Basically, all that had collapsed, all the concrete, the glass pipes,

...