When the World Trade Center towers collapsed on Sept. 11, 2001, and thousands of civilians fled from downtown New York, a steady stream of brave men and women made their way against the tide of evacuation towards Ground Zero. First responders, construction workers and volunteers gathered at the site of the attacks to aid in the effort of search and recovery. The rescue effort commenced at a feverish pace, with recovery workers laboring around the clock for days and weeks at a time. Personal safety was an afterthought at best. But as the fires smoldered below and the dust continued to settle from above, hope waned. Eventually, the reality set in that no more survivors would be pulled from the wreckage. What should have been an opportunity for the recovery workers to catch their collective breath was anything but.

Dust leads to health problems.

Almost immediately, it became apparent that the inescapable combination of smoke and particulate matter at Ground Zero was having an adverse affect on the health of the recovery workers. According to a 2002 study of the characterization of the dust that settled at the site, it was essentially a toxic brew of pulverized and combusted material. Among numerous other materials, the dust contained a fine mixture of steel, glass, heavy metals, asbestos, ash and many known chemical carcinogens. Respiratory symptoms, marked by chronic coughing and decreased lung function, emerged and persisted in a large proportion of the rescue workers exposed. These symptoms came to be known as WTC Cough Syndrome. By 2006, published studies reported that almost 70 percent of recovery workers had suffered high rates of respiratory abnormalities.

Dr. Ann Marie DiLorenzo has been a professor of Biology at Montclair State University for almost 30 years. Since the 1970s, her research interests have centered around the in vitro (grown in a test tube) culturing of animal cells. Today, she specializes in studying the effects of induced stress on such cells. Prior research efforts have included monitoring the effects of cadmium and lead on animal cell tissues.

Dr. Ann Marie DiLorenzo

In 2007, Dr. DiLorenzo attended a lecture given by Dr. Paul Lioy of Rutgers University on the chemical composition of WTC dust. Given her experience working with heavy metals, Dr. DiLorenzo took advantage of the opportunity to study such a unique amalgamation of toxins. After securing a sample from Dr. Lioy, she went to work with a team of undergraduate and graduate students to study the effects of the WTC dust on human lung tissue.

Dr. Paul Lioy

“The problems with WTC dust have been the lung issues that we’re hearing about; the firemen and the first responders who were exposed. So that’s why we started looking at human lung cultures,” explains DiLorenzo.

One of eight students involved with the research and lead author of the paper the group would eventually publish was then graduate student Constantino “Gus” Lambroussis.

“If you look at what is actually physically in the WTC dust, you will see a whole slew of heavy metals. So any of the heavy metals we were already looking at in our [other cell culture

research], you can find to some degree within the WTC dust,” Lambroussis said.

The group focused their effort on two responses of lung tissue to exposure of the dust. Cell proliferation rates (reproduction rates) and rates of apoptosis (naturally occurring cell death) were measured at different concentrations of dust exposure. Upon analysis of the data, the trends were clear. With increasing concentrations of WTC dust exposure, the lung cells reproduced at a significantly lower rate and died-off at a significantly quicker rate. As a control measure, cells were also exposed to different concentrations of household dust and gypsum (dry wall). The rates of apoptosis were measured for these two substances as well and they did not have nearly the same detrimental effect on lung tissue that the WTC dust did. Furthermore, the particulate size of WTC dust was compared to both household dust and gypsum and found to be comparable, suggesting that it was the actual chemical composition of WTC dust that was responsible for the declines in cell health.

The group concluded that exposure to the WTC dust has a negative effect on lung cell viability. They think that the various chemical contaminants found in the dust have mutagenic properties that cause damage to the DNA of the cells. Such drastic decreases of cell viability in a human body would likely result in decreased lung function, such as that experienced by many of the recovery workers.

The group’s work was published in a 2009 edition of the Online Journal of Biological Sciences. A number of students in Dr. DiLorenzo’s lab are continuing to do research using in vitro culturing techniques.

MSU students conduct experiments.

“As a long-time teacher, I don’t want students depending on me. I want them to be able to work as a team. And as you can see, we have a team that worked on the project and is continuing,” said DiLorenzo.

Dr. Lioy, who served as a catalyst for the work done at MSU, has been recognized as an authority on the WTC dust and is set to publish a popular-audience book on the subject in the near future. He thinks that work done at Dr. DiLorenzo’s lab is important since it will contribute to a body research that focuses on the effects of more than one contaminant at a time.

“[The discipline of toxicology] has been provided a wake-up call with the WTC event and fully recognizes the fact we’re usually not dealing with a single chemical when talking environmental issues,” Dr. Lioy said. “The adverse effects that are being observed probably come as a result of the synergism and antagonism of a whole host of chemicals in the WTC dust and original unrecorded gaseous releases. This is important to recognize if we are to truly understand the complexities of an exposure-response mechanism.”

Scott Buchanan

Staff Writer