U of T public health experts on what 9/11 and its aftermath revealed about air contaminants

Fire and rescue workers search through the rubble of the World Trade Center in the days after the 9/11 attacks as a plume of dust swirls in the air (Beth A. Keiser/AFP via Getty Images)

On the 20th anniversary of 9/11, Heidi Singer, director of communications at the University of Toronto’s Dalla Lana School of Public Health, recounts her personal experience with the tragedy and its aftermath before sitting down with three environmental health experts – Miriam Diamond, Paul Bozek and Christine Oliver – to talk about lingering health impacts and lessons learned.

White smoke rolled in from lower Manhattan, wrapping the Brooklyn waterfront in a sudden haze. The top third of the second tower had just crumbled to the ground, and I was on my bike, pedalling as fast as possible to the World Trade Center.

It was the morning of Sept. 11, 2001, and I was a reporter for the Staten Island Advance newspaper, living in Brooklyn.   

Normally congested streets were almost empty – people were pulled over in clumps, listening to the radio, learning about other attacks in other places. In those first few hours, we were terrified, wondering if the world was going to end.

Nobody thought too hard about the white smoke. Or the dust that covered the blank-faced people marching home across the Brooklyn Bridge and powdered the silent, empty streets like fresh snow.

A single police officer stood guard at the entrance to lower Manhattan. I showed him my press credentials allowing me to cross police lines. He tried to stop me, but I argued until he gave in. As I headed toward Ground Zero, he handed me a mask, saying, “Here, if you’re going in, at least take this.”  I have no memory of using it.

I breathed that dust all day and again two days later, working directly on the pile of debris, shovelling out the dead one bucket at a time. I’ll never forget the acrid taste of it. I smelled it for two months afterward from my desk in the press room of city hall as the fires continued to burn nearby. I developed “the cough” – an irritating constant hacking that first responders and residents of lower Manhattan got in those first weeks. A decade later, I was diagnosed with one of the cancers believed to be linked to 9/11 exposure.

Today, I’m haunted by the attack – the catastrophe, the lives lost, but also by the terrible health consequences that crept up on so many of us. The firefighters I interviewed who could barely walk due to lung damage. The cancers. The undocumented immigrants who did the dirtiest work cleaning up the rubble, then struggled to get help for their ruined health.

The smoke and dust have followed me through the years, a constant reminder of the risks we take, many of them reckless. Mostly I regret being there. But now, facing a very different public health disaster, these memories give me courage to ask people to mask when they’re not following public health guidelines, or to engage the hesitant in dialogue about vaccination.  

Twenty years later, I wonder what the experts have learned about the environmental health consequences of that terrible day – and whether much has changed. Would firefighters today be taking deep breaths of asbestos and silica dust as they worked themselves to the bone trying to dig out victims? Would exhausted recovery workers taking the Staten Island ferry home in the middle of the night simply be told to take a hot shower and throw their dusty clothes in the laundry? Would I as a reporter have been allowed into Ground Zero at all?

Left to right: Miriam Diamond, Paul Bozek and Christine Oliver (Photos by Camilla Pucholt, Adam Coish and courtesy of Christine Oliver)

For answers, I turned to three environmental health experts at U of T’s Dalla Lana School of Public Health: Christine Oliver, an adjunct professor, was based in Boston on 9/11 and subsequently treated some of the first responders and studied their unique illnesses; Professor Miriam Diamond immediately began putting together a team of graduate students from her U of T office who drove all night to lower Manhattan to measure contaminants in the air; and Associate Professor Paul Bozek, an asbestos and PPE expert who still uses environmental health lessons from that day in his work helping to protect firefighters and others with high-risk jobs.

Here is an edited transcript of the conversation:

Singer: What environmental health lessons have been learned from 9/11 in the past 20 years?

Oliver: I think for me it was a wake-up call in terms of the types of diseases that have emerged related to these exposures – the chronic rhinosinusitis and the gastroesophageal reflux disease (GERD). The cancers and the asthma and bronchitis were not a big surprise. But a cluster of four sarcoidosis cases was reported following 9/11, and that was surprising. This is a rare, serious inflammatory disease that affects the lungs primarily. At the time, it was considered a disease of unknown cause. In 2001 we were just beginning to recognize environmental factors as possibly causal. I started to look at what could have caused it in responders, and silica has turned out to be an exposure that’s associated with sarcoidosis. Silica was in the dust from the World Trade Center.

Bozek: It was a big experiment that allowed us to make a lot of connections clearer in terms of cause and effect. Normally, with broad-based population studies, it’s very difficult to look at low-level particle exposure and make that cause-and-effect relationship. But because of the acute nature of 9/11, we learned a lot. And they identified how far the contamination spread, which allowed them to track health effects.

A New York City firefighter, covered in dust, walks away from Ground Zero (photo by Anthony Correia/Getty Images)

Diamond: 9/11 was a profound and extreme disaster that accelerated our learning considerably around the chemical intensity of our cities. At the time, I was surprised and dismayed at the frequency of “ordinary” building fires in cities that put residents at risk. The incidence of these fires has gone down but the types of materials used in cities can potentially exacerbate toxicity. For the World Trade Center, we learned of the PCBs in the basement of one of the buildings. A very complex soup of toxic compounds was created by the lower temperature combustion of all the stuff in the towers, all the electronics and upholstered furniture.

Just think of all those wires. All those motherboards that already contained toxic materials. It became even more of a concern with this low temperature combustion. Since then, our cities have become filled with yet more wires and synthetic chemicals as we have replaced our trees with an urban landscape. We don’t just have wood furniture; we have particleboard furniture held together with all these synthetic resins. There’s shockingly little done on the actual chemistry of these mixtures of building materials, especially if they burn in a structural fire. My concern is what did we learn, what haven’t we learned and how are we just continuing on and making things worse?

The other big picture learning was that wars also released this terrible toxic mess. When the war in the former Yugoslavia was underway, bombing was done strategically at electrical transformer stations containing toxic PCBs and other hazardous dielectric fluids. The twin towers had major electrical transformer infrastructure because of the large number of people there. And this isn’t talked about much, the aftermath. You’ve got the acute effects of war but there are horrible aftermaths also. Tons of ordinary bombs just hitting houses and workplaces that are now stuffed with toxic materials that have become more toxic when combusted at these lower temperatures. 

Bozek: It’s practically assumed now that if a firefighter has cancer it must be work-related. 9/11 certainly raised their awareness, and also in the academic world, of contamination of clothing, and they’re much more acutely aware of the need to use respiratory protection, supplied air these days even for a small fire compared to 20 years ago. The captain is yelling at people to make sure they use their supplied air even if it’s a small fire they can put out in a few minutes.

Emergency personnel on site at the World Trade Center wreckage in 2001 (photo courtesy of Heidi Singer)

Oliver: In early days after 9/11 the group of workers least likely to wear respirators were firefighters. It was very surprising.

Singer: Not to me. I don’t know if anyone looked into why, but I can tell you those firefighters felt guilty because they lived and their friends died. They said the respirators slowed them down. They knew nobody was coming out of that pile alive. They knew it that night, but they were still working themselves into the ground trying to dig them out.

But that said, it sounds like we learned a lot, but big picture, some of the hardest lessons of 9/11 weren’t learned because what can you do about our increasingly wired society? How can we learn these lessons that our cities are becoming more and more vulnerable to toxic environmental events? Would we have to reinvent our lives and our cities to really learn the big lessons?

Bozek: Even ‘little picture’ learnings didn’t happen so fast. It took quite a while before we banned asbestos, and that was one of the biggest concerns from the World Trade Center disaster. When I was a student, fiberglass had an exposure limit that was much higher, but now it’s getting to the same level that asbestos was at on 9/11.

Diamond: It’s not just about what we’ve learned but who has learned what? The academic and medical worlds have learned. But as societies as a whole continue to become more complex, it’s a matter of translating the learning into action like building codes. Our regulatory systems are very complex, and in Canada they’re not always transparent. The academics are sometimes brought in to discuss such issues around the governance table, but special interests can effectively lobby against the science as they have a key to the back door of politicians.

Heidi Singer in New York on Sept 13, 2001 (photo courtesy of Heidi Singer)

Singer: I want to show you a picture of myself on Sept. 13. I was a reporter for the Staten Island Advance newspaper at the time, and the Red Cross brought a few of us into Ground Zero on the ferry. We ended up working on the ‘bucket brigade,’ trying to dig people out. What comes to mind when you look at that photo?

Bozek: First, your mask is looking too clean, so you weren’t wearing it enough compared to the dust on that car behind you. It looks like volcanic ashes. My other reaction is that I wish they’d kept you out. That white-ish dust was primarily from silica and gypsum, which settles deeply in the lung, and contains some known carcinogens. At that point, the major white cloud had dispersed, but the particle content from the very fine stuff would still have been quite high. It’s the stuff you can’t see that gets deepest into your lungs and can cause major concerns.

Hopefully after COVID, we’ve all learned about the value of N95s, as opposed to reporters rushing into a situation without any PPE at all.

Oliver: Maybe that’s a lesson we can bring in after Sept 11. Consciousness is higher with regards to the need to protect oneself from contaminants. Use of respiratory protection, even if it’s in the form of a dust mask or N95, is a good thing.

Singer: I’m stunned looking at that photo. I haven’t looked at it in years. Why wasn’t I wearing my mask? What good was it around my neck?

Oliver: Do you remember why you didn’t?

Singer: I was young, I was healthy. The idea that I could get cancer from that dust was so far from my mind. It was, I think, a few weeks before people started developing the cough. We were in the middle of the biggest thing that had ever happened to us. We were the ones who survived and we weren’t focused on our health.

But there was one moment. I ran into a city health official I knew, and she was talking about how terrible it was that they couldn’t get firefighters to wear respirators. When I mentioned I was on the pile, she looked at me with pity. It was one of the few times I got uneasy. I wondered, what does she know that I don’t?

Diamond: I remember at the time there was quite a delay after the 9/11 attack during which the Environmental Protection Agency (EPA) didn’t bring in air monitors. Conspiracies theories arose in the aftermath around the EPA. People contacted us [at U of T] as honest brokers. There was this feeling of minimizing the potential health threat to get back to so called normalcy and just to keep going. There was minimal testing in people’s homes nearby. I was very surprised that the EPA didn’t take measurements immediately. I thought it was untoward. But Canada probably would have been even worse given our limited ability to respond to disasters.

Oliver: If there’s an overriding lesson to be learned it’s the importance of education. But what are we going to do about this? How are we going to change the way we live in urban environments and the composition and structure of buildings? The World Trade Center does illustrate the importance and necessity of education and that carries over to COVID.

Diamond: I really agree with what you said, Christine. One of the key things about education we haven’t figured out very well is connecting the dots. Our education is tidbits that we don’t have time to integrate. The sad anniversary of 9/11 provides an opportunity to have this more integrative view of the need for a multipronged approach: the education, and regulatory frameworks to implement lessons.

Oliver: I think to some extent the pandemic has said we can do this, we can change how we live and work. Maybe that will be the only gift from the pandemic.

Diamond: It is a big gift. Because what happened after 9/11, the change in regulation was in terms of population surveillance for the purposes of security; there was a increase of resources devoted to security that we weren’t fully aware of. And there’s only so much money to go around. It comes out of a pot that could be for education.

Singer: What’s the one thing you wish had been done differently during 9/11 from an environmental health perspective?

Bozek: Measure it. We don’t do enough measurements to know what the risk is. If they would have done the measurements and said we have all this stuff in the air, they would have taken more precautions. But they walked in blind because they were dealing with the immediate trauma, then the cleanup and trying to get back to normal without understanding the risk. If you don’t do the measurement, assume it’s a worst-case scenario and go in with the spacesuits. 




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