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Sifting Through the Dust at Ground Zero
by Daniel A. Martino, Environmental Risk Limited

Like most Americans, I can vividly remember the morning of September 11th. I was sitting at my desk discussing mold sampling with a client. The next thing I knew, a colleague handed me a picture of the World Trade Center North Tower in flames. Within minutes, our entire firm migrated to our training room to watch the events unfold live on television. We all watched together as the towers fell, and there was a shared feeling in the pit of our stomachs that couldn’t quite be put into words. If you told me that day that I would be spending the next several months working in and around “ground zero,” I would have said you were crazy.

I was fortunate (or perhaps unfortunate) enough to see the many sides of the terrorist attacks on the World Trade Center. From working behind the police line of ground zero, to talking to rescue workers including police officers, fire fighters, OSHA staff, and FEMA workers, to working inside buildings that remained standing but were heavily contaminated as far as 15 blocks away from ground zero, I got to see first-hand how much of the city was actually impacted from the terrorist attacks.

A majority of the work at the site involved collecting bulk dust samples and conducting air monitoring. A contracting firm representing several building owners had retained ERL to collect dust samples to be analyzed by a certified laboratory for a number of constituents and to perform air monitoring at those selected locations. Their request for analysis was prompted by the fact that building owners were frustrated by hearing from federal agencies that the dust wasn’t harmful, yet after spending a day in lower Manhattan, your nose and eyes often became irritated. In fact, as a member of the health and safety community, I often found myself being asked for advice by members of the rescue effort, as well as by residents of lower Manhattan, on topics such as respiratory protection and the proper use of personal protective equipment.

The dust, which has come to be known to those of us who collected it throughout the city as the World Trade Center (WTC) dust, can be described as a pale gray colored fibrous material that to the touch feels like a powder similar to baking flour. Most people don’t realize what actually makes up the WTC dust. When the twin towers collapsed, every part of the buildings, as well as everything inside, was literally pulverized. Components of the buildings included items like HVAC systems, lights, carpets, ceiling tiles, and glass. Furnishings inside the building would have included computers, desks, chairs, books, toilets, sinks, and other basic office items. All of these elements make up the composition of the WTC dust. Rescue workers have told me that in months of digging and searching, not only were human remains few and far between, but very few items resembling office paraphernalia were discovered, even though the Twin Towers included hundreds of floors of offices. To attempt to put this in perspective, the next time you’re in an office building, take a look around you and imagine everything that you can see completely pounded into dust. Even now, that’s hard for me to imagine as I look around my office.

Another thing that most people don’t realize is the extent of the contamination of the WTC dust. To understand this, you must first understand how a typical HVAC systems works within a New York City skyscraper. In many cases, the HVAC system sucks in air from a fresh air intake, usually located on the roof of the building; the system then disperses this air throughout the entire building. On September 11th, shutting down their HVAC systems was not foremost on the minds of building engineers throughout Manhattan; most explained that they left work immediately after the first plane hit to get their children out of school, or to rush home to find their significant others. Many of the images of New York City after the attacks showed the massive cloud of smoke that engulfed buildings throughout Manhattan. Since air intakes were still operational, dust was being drawn into these buildings and dispersed throughout. As a result, not only were entire HVAC systems contaminated, they also delivered the dust to every square inch of these buildings.

Locating samples of the WTC dust to collect was never a problem because it was everywhere. As long as four months after the attacks, I could locate the dust inside ductwork, within elevator systems, on elevator cables, and in basements within elevator pits. The dust could also be found on window ledges, on rooftops, within electrical and mechanical rooms, and even in carpets that had been cleaned professionally many times over.

When submitting samples for laboratory analysis, initially, we didn’t know what we were looking for. We soon learned that we would be sampling the WTC dust for almost everything under the sun. The dust has undergone metal scans and asbestos fiber counts; it has also been analyzed to determine pH levels, as well as the levels of carbonate and OH alkalinity. Additional analysis included fluoride, chloride, nitrate, phosphate, and sulfate levels. You might think that after all this analysis, everything has been resolved; in fact, many, many issues are still pending.

I also had the task of collecting samples from within many residential buildings surrounding ground zero. Listening to people relate their stories of 9/11, I saw firsthand the ways in which their lives were forever changed. I witnessed the devastation of homes, and heard of the precious personal belongings that were lost or ruined. Nothing could spare these people from the loss of personal valuables and the loss of homes that had been filled with emotion and memories.

My work in New York City has been a poignant experience. Not only has it changed my outlook on life, but it has also affected the way I look at my role as a health and safety professional. I still perform my duties as a health and safety consultant, but am now also part of ERL’s vulnerability assessment team. With a focus on Emergency Action Plans and Emergency Response Plans, I’m working with companies to help them prepare for emergencies of any sort. We all know now that “It can’t happen to us” just isn’t true.

Dan Martino is a health and safety consultant with Environmental Risk Limited in Bloomfield, Connecticut. For more information, please contact him at (860) 242-9933 or via e-mail at


Copyright 2002 New England's Environment Magazine