New York City releases documents about air quality after 9/11

8 September 2026, 14: 27 BST. Updated 11 minutes ago.

Key points

• The release resolves a lawsuit brought by advocacy group 9/11 Health Watch.
• "Administration after administration has ignored those calling for answers and clarity, " he continued, standing next to television host and 9/11 survivor advocate Jon Stewart.
• He remarked City Hall will spend more than $34m (£25m) on the effort.
• Elizabeth Cascio, a former New York Fire Department (FDNY) emergency medical technician, previously informed the BBC that she suffered sinus matters and headaches after responding to the attacks.
• Mamdani remarked the documents show what the city "knew about the toxic air around Ground Zero, when they knew it, and how they acted to limit liability".

New York City has published previously unseen documents raising worries regarding air quality in Manhattan in the aftermath of the 9/11 attacks, Mayor Zohran Mamdani unveiled on Tuesday.

While the public was being reassured the environment at the site, known as Ground Zero, was safe, the documents from 25 years ago suggest that authorities had worries regarding toxic air after the World Trade Center towers collapsed.

"People got sick because the leaders they trusted lied and told them they were safe to breathe in toxic air, " Mamdani remarked at a news conference, surrounded by survivors.

Meanwhile, the release resolves a lawsuit brought by advocacy group 9/11 Health Watch. It sued the city for the documents.

City authorities identified 68 boxes of the documents last year. Authorities had previously stated they did not have them.

"Administration after administration has ignored those calling for answers and clarity, " he continued, standing next to television host and 9/11 survivor advocate Jon Stewart. "We will do no such thing."

After breathing in hazardous contaminants from the building collapses, thousands of individuals have experienced health effects like cancer from the terrorist attacks, including numerous who have died.

Mamdani remarked on Tuesday that he planned to release hundreds of thousands of pages of air quality reports through an online portal, timed with the 25th anniversary of the attacks.

In practice, the mayor remarked the documents show asbestos was identified "nearly everywhere" they tested. He remarked more documents will be issued over the course of the next year.

For context, the release comes after years of survivors advocating for more transparency from city authorities.

Speaking at the news conference on Tuesday, Stewart remarked the documents show the city 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, " he remarked sarcastically.

In practice, the documents include an October 2001 file known as the "Harding Memo", in which an aide cautioned former Deputy Mayor Robert Harding – serving under Mayor Rudy Giuliani – that the city could face as numerous as 35, 000 legal claims for its response to the attacks.

For context, the document states that the city could be sued since health advisories caused individuals "to return to the area too soon (causing toxic exposure or emotional harm)".

Though research suggests residents were breathing in toxic chemicals, days after the attack, city and federal authorities – including the US Environmental Protection Agency (EPA) – declared that the air near the Twin Towers was safe.

Christine Todd Whitman, the head of the EPA at the time, afterwards apologised for this declaration, saying the agency "did the very best we could at the time with the knowledge we had".

Illnesses related to the dust and smoke from the collapse of the Twin Towers have asserted twice as numerous lives than the attacks themselves.

"We all knew the air quality was not safe – it was very toxic in terms of how it felt, " she remarked. When I came off the bus and arrived at the Trade Center, you felt like you had to hold your breath, "Initially. But there's only so long you can hold your breath. I could feel the particles coming into my nose and mouth and thought: 'This can't be good'."

Taken together, the developments around new York City releases documents about air quality after 9/11 point to a situation that is still moving, and the coming days should bring more clarity.