New documents reveal what NYC knew about air toxicity after 9/11

In short:

New York City Mayor Zohran Mamdani has released thousands of documents detailing what was known about toxic smoke from the September 11, 2001 attacks on the World Trade Center (WTC).

This Friday will mark 25 years since Al Qaeda terrorists flew hijacked planes into the Twin Towers, the Pentagon and into a field in Pennsylvania.

Mr Mamdani says the documents show NYC administrations did not release all they knew about the toxic effects of smoke from the WTC collapse.

New York City Mayor Zohran Mamdani has released more than 170,000 pages of documents showing that the city did not disclose all it knew about air toxicity after the September 11, 2001 attacks.

The release comes ahead of the 25th anniversary of the terrorist attacks that killed 2,977 people, in the United States, mostly from the collapse of the Twin Towers in New York.

More than 9,400 have died from illnesses linked to their exposure to the area in the years since, according to a federal medical monitoring program.

"These are documents that show what the city knew about the toxic air around Ground Zero, when they knew it, and how they acted to limit liability," the mayor told a news conference.

Mr Mamdani said the thousands of documents contain information on health concerns, air quality and the city's response to the attacks.

The release is part of an agreement with 9/11 Health Watch, a victims' advocacy group that had taken legal action to compel the city to make the documents public.

"For 25 years, four different Mayoral administrations kept from the public, the US Congress, and the City Council documents showing what the City actually knew about the danger of the toxic chemicals in Lower Manhattan and Western Brooklyn after the World Trade Center collapse, even as City officials continued messaging to the public that the air was 'safe and acceptable'," the group's director Benjamin Chevat said in a statement.

When asked about the names of officials who had withheld information from the public, Mr Mamdani said, "this goes across a multitude of those that New Yorkers have trusted."

Rudy Guliani was mayor of New York City at the time of the attacks.

In recent days, politicians including Mr Guliani and some relatives of September 11 victims have called for Mr Mamdani, NYC's first Muslim mayor, to skip this year's memorial. Other families have defended the mayor who says he will attend despite the criticism.