Accessibility links Skip to main content Keyboard shortcuts for audio player Open Navigation Menu --> Newsletters NPR Shop Get NPR+ Close Navigation Menu Home News Expand/collapse submenu for News National World Politics Business Health Science Climate Race Culture Expand/collapse submenu for Culture Books Movies Television Pop Culture Food Art & Design Performing Arts Life Kit Gaming Music Expand/collapse submenu for Music Tiny Desk New Music Friday All Songs Considered Music Features Live Sessions Podcasts & Shows Expand/collapse submenu for Podcasts & Shows Daily Morning Edition Weekend Edition Saturday Weekend Edition Sunday All Things Considered Up First Here & Now NPR Politics Podcast Featured Wait Wait...Don't Tell Me! Fresh Air Wild Card with Rachel Martin It's Been a Minute Embedded Get NPR+ More Podcasts & Shows Search Newsletters NPR Shop Get NPR+ Tiny Desk New Music Friday All Songs Considered Music Features Live Sessions About NPR Diversity Support Careers Press Ethics New York City Mayor Mamdani releases documents related to post-9/11 air quality New York City has released 170,000 documents it says show officials knew the air quality around the World Trade Center after 9/11 was dangerous to breathe, but they didn't warn local residents. National New York City Mayor Mamdani releases documents related to post-9/11 air quality September 9, 20264:46 AM ET Heard on Morning Edition By Brian Mann , Michel Martin New York City Mayor Mamdani releases documents related to post-9/11 air quality Listen · 3:47 3:47 Transcript Toggle more options Download Embed Embed "> <iframe src="https://www.npr.org/player/embed/nx-s1-5961417/nx-s1-9918933" width="100%" height="290" frameborder="0" scrolling="no" title="NPR embedded audio player"> Transcript New York City has released 170,000 documents it says show officials knew the air quality around the World Trade Center after 9/11 was dangerous to breathe, but they didn't warn local residents. Sponsor Message Transcript
MICHEL MARTIN, HOST:
As part of our reporting this week, marking 25 years since the 9/11 terror attacks, we're going to turn this morning to New York City. For the first time, officials are releasing documents that reveal what was known about toxic air quality in Lower Manhattan in the weeks and even months after hijackers flew commercial airliners into the World Trade Center. NPR's Brian Mann has been reporting on this, and he's with us now. Brian, good morning.
BRIAN MANN, BYLINE: Good morning, Michel.
MARTIN: Why is New York City releasing this information now?
MANN: Mayor Zohran Mamdani spoke at a press conference yesterday. And he said the city had violated the public's trust by not coming clean about this data decades ago. After the attack, local, state and federal officials assured first responders working at ground zero and residents of Lower Manhattan that the air wasn't dangerous, and it turns out that wasn't true.
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ZOHRAN MAMDANI: People got sick because the leaders they trusted lied and told them they were safe to breathe in toxic air. And then, when they began to contend with the symptoms of the illnesses that followed, the government that had not hesitated to send them into harm's way was nowhere to be found.
MANN: Roughly 3,000 people died on 9/11 during the attack. But, Michel, there are now more than 35,000 first responders and survivors living with cancers linked to 9/11. That's according to the Centers for Disease Control and Prevention. And the CDC says at least 6,000 people who signed up for their federal 9/11 health program have died. It's not clear how many of those deaths were caused directly by these 9/11-related illnesses.
MARTIN: Brian, is it clear from these documents that there was some kind of a cover-up? By which I mean they knew that there was something wrong and made a decision not to disclose it.
MANN: Yeah. What we know is that very soon after the 9/11 attacks, researchers did see troubling signs that the air was dangerous. New York City collected more than 170,000 pages of data, and then they fought in court for years to prevent the public from seeing it. Comedian and activist Jon Stewart, who campaigned for years for more transparency - he spoke at yesterday's press conference.
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JON STEWART: They didn't recognize that the air that everyone was breathing in downtown Manhattan was toxic until October of 2001. So to be fair to them, they only buried that information for 25 years.
MANN: And Stewart said he hopes this information being made public will help more 9/11 survivors get the medical help they need.
MARTIN: You reached out to past New York City mayors who chose not to release this information. What did they say?
MANN: Well, we got no response from Mayors Bloomberg, de Blasio and Adams. But in response to an inquiry from NPR, former Mayor Rudy Giuliani's staff did post a comment on social media blaming the U.S. Environmental Protection Agency for saying the air quality was safe in Manhattan. They made a mistake, the Giuliani statement said, adding, quote, "no one covered it up."
In 2016, Michel, former EPA administrator Christine Todd Whitman did apologize in an interview with The Guardian newspaper for failing to provide accurate information to the public. But then for a decade after that, New York City officials kept fighting to keep all these documents under wraps.
MARTIN: Do we know why so many city officials, both Democrats and Republicans, withheld this information?
MANN: We know from one internal memo that was released yesterday - written shortly after 9/11 - that city officials were worried about lawsuits. Mayor Mamdani was asked if he fears this information might open a new floodgate of claims against the city. He said transparency and accountability outweigh any financial concerns.
MARTIN: That is NPR's Brian Mann, who will be at the 9/11 Memorial in Manhattan on Friday as part of NPR's coverage of the 25th anniversary of the attack. Brian, thank you so much.
MANN: Thank you. Copyright © 2026 NPR. All rights reserved. Visit our website terms of use and permissions pages at www.npr.org for further information. Accuracy and availability of NPR transcripts may vary. Transcript text may be revised to correct errors or match updates to audio. Audio on npr.org may be edited after its original broadcast or publication. The authoritative record of NPR’s programming is the audio record. NPR does not offer or accept money for coverage or interviews. Anyone who makes such an offer or request is not an NPR employee and does not represent NPR. Facebook Flipboard Email Read & Listen Home News Culture Music Podcasts & Shows Connect Newsletters Facebook Instagram Press Public Editor Corrections Transcripts Contact & Help About NPR Overview Diversity NPR Network Accessibility Ethics Finances Get Involved Support Public Radio Sponsor NPR NPR Careers NPR Shop NPR Extra Terms of Use Privacy Your Privacy Choices Text Only Sponsor Message Sponsor Message Become an NPR sponsor (function () { var loadPageJs = function () { (window.webpackJsonp=window.webpackJsonp||[]).push([[22],{312:function(e,n,o){o.p=NPR.serverVars.webpackPublicPath,Promise.all([o.e(1),o.e(2),o.e(3),o.e(4),o.e(80)]).then((e=>{o(15),o(770),o(156),o(177),o(95),o(449),o(256),o(131),o(133),o(756),o(176),o(757),o(257),o(80),o(775)}).bind(null,o)).catch(o.oe)},784:function(e,n,o){e.exports=o(312)}},[[784,0]]]); }; if (document.readyState === 'complete') { loadPageJs(); } else { window.addEventListener('load', function load() { window.removeEventListener('load', load, false); loadPageJs(); }); } })();