The Twin Towers came down in a cloud of toxic dust. Its health impact has lasted decades
By Lauren Mascarenhas, CNN
(CNN) — As a child growing up in Queens, Frank Kotnik watched the Twin Towers across the river growing taller and taller as their construction neared completion.
As a teenager, he and his friends once snuck into the original World Trade Center, hoping to take in the views from the roof. They made it almost all the way up before getting busted by a security guard. Still, as Kotnik looked out the window from his vantage point, towering above Manhattan, he felt a sense of awe.
And as an adult, Kotnik drove with two of his buddies, directly from a 12-hour shift as a blacksmith for the New York City Department of Transportation, to Ground Zero on September 13, 2001. In disbelief, he walked through a “moonscape” where the towers once stood.
It was all dust – the bustling life contained in those towers, the office spaces, metals, desks and chairs, computers, plastics, cleaning products, electronics and more that once sat inside the original World Trade Center had been pulverized into a thick powder that rose above Lower Manhattan as the towers came down and lingered long after.
Kotnik spent weeks dedicating his time and skills to the response effort following the 9/11 attacks, sifting through the dust to cut steel and clear debris.
“Thousands of New Yorkers were murdered. I wasn’t going to go play golf. If I could help somehow, I was going to help,” Kotnik, now 66 and in recovery from bladder cancer, told CNN.
Nearly 25 years later, the release of over 170,000 pages of documents from New York City has left the public reckoning with what exactly was contained in that dust, how much officials knew at the time and the lasting health consequences now faced by thousands of people.
Some of the information contained in the documents revealed what officials and doctors have known for years – that the dust contained materials and chemicals that can make people very sick.
Hidden in the dust
The dust was a complex mixture of inorganic and organic chemicals that lingered for a long time in large quantities – making it different from the exposure to natural dust seen in people living in areas like the Great Plains or the Southwest, Dr. Ana Navas-Acien, chair of environmental health sciences at Columbia University’s Mailman School of Public Health, told CNN.
“It’s not common for humans to be exposed to that level of dust,” Navas-Acien said.
Particularly concerning are the inorganic materials in the dust, including metals like cadmium and lead, she said.
“We know that metal inhalation means complete absorption very often, and those metals are not supposed to be in the body. They are going to be interacting with our own proteins. They are going to be absorbed in our different tissues, especially where minerals and metals are very relevant, such as the bone,” she noted.
Those metals can persist in the body for decades, she said.
Other materials found in the dust include asbestos, a known carcinogen which lingered after the attacks and has long been linked to mesothelioma, a rare and aggressive cancer with a long latency period and symptoms that often don’t present until many years later, according to the Mesothelioma Center.
Other materials like wood, plastics and glass were also pulverized into fine particles contained in the dust.
“They became very, very thin, very fine particles,” she said. “The finer they are, the more deep into the lungs they can reach.”
People who were in and around the dust weren’t just dealing with exposure to one material or chemical, Navas-Acien noted, it was a mixture of all of them. That dust could have impacts on the lungs, brain, cardiovascular system and more, she said, and researchers are still trying to understand the scope of the health consequences.
In addition to the years-long research already done in this area, experts are now poring over pages upon pages of the newly released documents to determine whether they’ve fully and accurately characterized exactly what was contained in the dust around Ground Zero.
Health consequences emerge over time
Over the years, Kotnik had watched his friends who worked with him after 9/11 fall ill. Some got cancer. Some got brain tumors. Some died.
Two decades after Kotnik spent time working in the moonscape of dust that blanketed Lower Manhattan, he discovered blood in his urine. Testing soon revealed that he had bladder cancer.
At one point, a friend of Kotnik’s suggested he enroll in the World Trade Center Health Program, so he did. The World Trade Center Health Program offers federal funding for the care of those with certain cancers and health conditions related to 9/11 exposure.
Dr. Jacqueline Moline, who directs the Northwell Health Queens World Trade Center Health Program, said she began treating patients in the immediate aftermath of 9/11 – before federal funding for the programs came in around 2002. She and her colleagues have since been monitoring the health effects they’ve seen as a result of the dust.
In the early days, Moline said they saw conditions like sinusitis, rhinitis, laryngitis, bronchitis, reactive airways disease, asthma, PTSD, anxiety and gastroesophageal reflux disease.
Much of what was contained in the dust “can penetrate into the tissue and cause irritation, and that may be why so many of the problems were longer lasting,” she said.
The doctor noted she and her colleagues have seen permanent damage to the aerodigestive tract, including the upper and lower respiratory systems and the esophagus.
While many doctors have long known that asbestos, gypsum and other components of the dust made people sick, the level and persistence of contamination revealed in the documents released this week may help explain some of the long-lasting health conditions doctors have observed, Moline said.
About 10 years after 9/11, doctors began seeing cancers like mesothelioma, leukemia and lymphoma develop in World Trade Center Program patients, Moline noted.
“And over time we’ve seen more and more cancers, so we expect that we will continue to see a large number of cancers going forward,” she added.
Research into other potential health impacts, like mental health, cognitive function and fertility can help close the gaps in our collective understanding of the consequences of exposure to the dust, she noted.
For those who may have had exposure to the 9/11 dust, checking in with their doctors or joining one of the World Trade Center Health programs can be critical to early diagnosis and treatment, Moline said.
But treatment, as Kotnik found, is not always easy.
“Ain’t no joke,” he said of his chemotherapy sessions. “Kicks your ass.”
Eventually, Kotnik said he underwent a seven and a half-hour surgery, in which doctors removed his bladder and used a section of his bowel to create a new one. Before the surgery, Kotnik’s doctors at Northwell Health warned him the road ahead wouldn’t be easy.
“I’ll have a better quality of life if I go this way, but it’s a longer recovery period – and I’m still in it,” he said.
But Kotnik has never shied away from hard work. After 9/11, he spent years working on the Avenue of the Americas, the Brooklyn Bridge and other projects for the city’s Department of Transportation before retiring. His footprint is all over the city.
The hazards that linger after a disaster
In Kotnik’s memory, those early days of working in the dust were “organized chaos.”
The renewed spotlight on that time has raised new questions about accountability.
“People got sick because the leaders they trusted lied and told them they were safe to breathe in toxic air,” New York Mayor Zohran Mamdani said during Tuesday’s announcement of the release of the documents.
At the time, few workers or residents had a complete picture of what was happening, said Joseph Allen, professor of exposure assessment science at the Harvard T.H. Chan School of Public Health.
“There was a great sense of national pride. People wanted to be back and volunteered to be down there. I think we knew it was toxic, and I think what these files are covering is that there was more known than the public was aware of,” Allen told CNN.
While progress in disaster response has been made in the last 25 years, there’s still a ways to go, Allen said. His research has found parallels between the 9/11 response and the response to the devastating Los Angeles area fires in 2025.
“Similarly, we found that the hazard remained many months after the fires were out, when a lot of people thought it was safe – and a lot of people were told it was safe,” he said.
It’s a pattern that has been observed with other disasters, Andrew Whelton, professor of civil and construction engineering and sustainability engineering and environmental engineering at Purdue University, told CNN.
People are faced with extreme uncertainty and a situation that is changing minute by minute, and they make decisions without all of the information they need, he said.
“That is the story of how people make decisions after these disasters,” Whelton said. “The only way to break that cycle is to recognize that what happened after the World Trade Center collapse in the exposures to the workers and residents and visitors was unacceptable, and then pivoting off that and saying we will not allow workers, residents and visitors to be similarly exposed to anything like this again.”
The information learned after 9/11 can be transferred to other disaster situations, like earthquakes, fires and chemical explosions, Whelton said. He works with a team through his university that helps officials navigate uncertainty after disasters such as the Lahaina wildfires in Maui.
“What I hope is taken from this is that there’s a doubling down on understanding the importance of protecting workers that we expect to go into harm’s way, and being honest with them about the hazards that they could face, protecting them from the hazards they do face, and then walking with them in the future to make sure that we didn’t miss anything, and their health is protected,” Whelton said.
After everything Kotnik has experienced in the past 25 years – watching his friends fall ill with 9/11-related cancers and health issues, his own bladder cancer diagnosis, the brutal chemo sessions, the intensive surgery – he considers the question: Would he go back and volunteer in that dust again?
“Absolutely not,” Kotnik said. “I’m not stupid.”
But Kotnik said he doesn’t blame anyone for what’s happened except those who carried out the 9/11 attacks.
He said he’s immensely grateful for the team at Northwell Health that helped him tackle his cancer.
Doctors like Moline are hopeful that 25 years after the 9/11 attacks, more people impacted by the lingering dust and debris will have the information they need to find help.
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