New York City Sat on 170,000 Pages Proving Officials Knew Ground Zero’s Air Was Toxic.
City Hall Denied The Records Even Existed — Until A Judge Called It “Arbitrary and Capricious.”
New York City released roughly 170,000 pages of records on September 8, 2026, showing officials knew Ground Zero’s air was dangerous long before — and long after — they told the public it was safe. The release, ordered by Mayor Zohran Mamdani (D-NYC), settled a Freedom of Information Law lawsuit brought by the nonprofit 9/11 Health Watch and its executive director, Ben Chevat.
The documents themselves trace back to 2001 and 2002. But the newer, sharper story is what happened between 2023 and 2026: the City’s own Law Department and Department of Environmental Protection told 9/11 Health Watch, in writing, that a diligent search had found no responsive records — while DEP was sitting on 68 boxes of them the entire time.
A state Supreme Court justice ruled in May 2026 that the denial violated New York’s public-records law and was “arbitrary and capricious.” The two-plus years of stonewalling happened entirely on the watch of Mayor Eric Adams (D-NYC), building on a 2021 request that Mayor Bill de Blasio (D-NYC) had simply let sit.
- 170,000 pages — released September 8, 2026, the first tranche of a public archive the City has committed to keep expanding · Source: 9/11 Health Watch
- 68 boxes — of “highly organized” 9/11-era records DEP admitted possessing in 2025, after two years of telling a court none could be found · Source: 9/11 Health Watch
- $34,000,000 — City budget line to build and run the new public records portal, FY2027 · Source: NYC Mayor's Office
- $4,000,000 — committed to a two-year Department of Investigation probe into how the City communicated 9/11 air-quality risk · Source: 9/11 Health Watch
- ~35,000 — potential plaintiffs the City's own Law Department estimated might sue over toxic exposure, per the October 2001 “Harding memo” · Source: Daily Caller News Foundation
The lawsuit that forced the release, an Article 78 proceeding known as Chevat v. DEP, was filed in 2024 after the City denied a 2023 Freedom of Information Law request from 9/11 Health Watch. The documents now public include air-quality monitoring reports, internal risk assessments, and correspondence among city agencies from the weeks and months after the towers fell — the record of what officials knew, set against what they told the public.
The public-facing claims are well known. Christine Todd Whitman (R), EPA Administrator under President George W. Bush (R), declared on September 18, 2001 that the air near Ground Zero was “safe to breathe” — a statement the EPA’s own Inspector General later found the agency lacked “sufficient data” to make. That 2003 Inspector General report also found the White House Council on Environmental Quality had pushed EPA to add reassuring language to press releases and strip out cautionary language before they went out. Whitman has since said the agency did the best it could with the information it had at the time.
The newly surfaced “Harding memo,” addressed in October 2001 to then-Deputy Mayor Robert Harding under Mayor Rudy Giuliani (R-NYC), shows City Hall’s Law Department separately estimating roughly 35,000 potential plaintiffs — about 10,000 expected to actually file — and weighing legislative options to cap the City’s liability, even as officials publicly urged residents and workers back into Lower Manhattan.
A November 2001 city audit cited in the records found elevated benzene concentrations near the towers’ footprint and rising asbestos levels at the Fresh Kills landfill on Staten Island, where WTC debris was being sorted. By August 2002, testing at Stuyvesant High School — reopened blocks from Ground Zero — found roughly 2.5 million asbestos structures per square centimeter in the auditorium carpet, about 500 times the EPA’s own cleanup benchmark of 5,000 structures per square centimeter. Asbestos, the documents show, turned up in nearly every location officials tested.
Independent science backed up what the internal memos described. A University of California, Davis team led by atmospheric physicist Thomas Cahill analyzed more than 8,000 air samples collected in October 2001 from a rooftop near the site and found concentrations of ultra-fine, lung-penetrating particulates the researchers called unmatched anywhere they had measured — worse, Cahill said, than the worst days downwind of Beijing’s coal plants or Kuwait’s oil-well fires.
“What did the City know about the dangers from the toxic cloud at Ground Zero, and when did it know it?”
Benjamin Chevat, Executive Director, 9/11 Health Watch
The human toll has now outpaced the attack itself. Nearly 2,700 people died in New York on September 11, 2001; more than 9,400 additional people have since died of illnesses linked to Ground Zero exposure, according to figures reported alongside the document release. More than 140,000 people nationwide have enrolled in the federal World Trade Center Health Program, and roughly 49,000 have been diagnosed with WTC-related cancers.
The 2001-era failures are two decades old. What is new is how New York City’s government handled the records about them. In 2021, Reps. Carolyn Maloney (D-NY) and Jerry Nadler (D-NY) asked Mayor Bill de Blasio (D-NYC) to review and release the City’s 9/11 files. The request went nowhere. In 2023, 9/11 Health Watch filed its own Freedom of Information Law request. FOIL Appeals Officer Jeffrey Lowell responded that a “diligent search” under Mayor Eric Adams (D-NYC) had “not identified any records responsive to your requests.”
.@NYCMayor Mamdani (D) announces the release of 9/11 records related to air quality: 'These are documents that show what the city knew about the air around Ground Zero, when they knew it, and how they acted to limit liability.'
When 9/11 Health Watch sued to compel disclosure, the City’s Law Department moved to dismiss the case as frivolous. In April 2024, Reps. Dan Goldman (D-NY) and Nadler wrote directly to Mayor Adams urging him to release the records. Only in 2025 did DEP reverse course, telling the court it in fact held 68 boxes of responsive material — memos, monitoring data and correspondence the Law Department itself had originally collected. On May 28, 2026, New York State Supreme Court Justice James G. Clynes ruled that the City’s FOIL denial violated state law and was “arbitrary and capricious,” clearing the path to the settlement Mamdani’s administration announced in September.
Break the record down by administration and the accountability picture spans both parties, unevenly. The original public-safety failure — Whitman’s EPA and Giuliani’s City Hall insisting the air was fine while their own Law Department quietly totaled up 35,000 potential plaintiffs — belongs to Republican-led federal and city government in 2001. The two-decade paper chase that followed, and the years of telling a court the records simply didn’t exist, played out entirely under Democratic City Hall: de Blasio’s inaction in 2021, then Adams’s Law Department and DEP denying the files’ existence from 2023 through 2025.
Christine Todd Whitman (R) — EPA Administrator, 2001–2003, under President George W. Bush (R); declared the air “safe to breathe” days after the attack.
Rudy Giuliani (R) — NYC Mayor, 1994–2001; administration received the October 2001 Harding memo on liability exposure.
Bill de Blasio (D) — NYC Mayor, 2014–2021; did not act on a 2021 congressional request to review the records.
Eric Adams (D) — NYC Mayor, 2022–2025; his Law Department and DEP denied the records existed, 2023–2025.
Zohran Mamdani (D) — NYC Mayor since January 2026; settled the case and released the first 170,000 pages.
James G. Clynes — NY State Supreme Court Justice; ruled the City’s FOIL denial “arbitrary and capricious.”
Not everyone is taking Mamdani’s framing at face value. City Council Member Joann Ariola (R-Queens) called the release “performative,” arguing the mayor timed it to “eat up the air time of the media” amid a separate controversy over whether he should attend Friday’s 25th-anniversary ceremony. Mamdani has said the delay itself was the scandal: “This was multiple mayoral administrations refusing to release documents that New Yorkers were owed.”
Zohran Mamdani has released 9/11 records showing city officials at the time purposely misled New Yorkers despite knowing it was unsafe to breathe around Ground Zero.
The 2001 failure to level with New Yorkers about Ground Zero’s air belongs to Whitman’s EPA and Giuliani’s City Hall, both Republican. But the newer failure — a city government that spent more than two years telling a court the records didn’t exist, until a judge called that position “arbitrary and capricious” — happened entirely under two consecutive Democratic mayors. Mamdani released the documents. His two Democratic predecessors are why it took a court order to get there.
