Anthony DePalma answered reader questions and comments about workers made sick after exposure to toxic materials at ground zero.

Q: I would like to know why the health focus is only below Canal Street? The wind was blowing north for months while the pile burned. I worked two blocks north of Canal and have had a many fold increase in sinus problems ever since September 2001. I believe we will discover that the health affects from five years ago will be of a much wider scope than what is being studied currently.

-- E.S.

A: Canal Street was selected by the Environmental Protection Agency as a cutoff based on their air monitoring and aerial photographs. However, there is also plenty of evidence showing that the plume of smoke from the burning pile was blown across lower Manhattan by the wind in the days after the towers collapsed, reaching farther up into Manhattan and into parts of Brooklyn and New Jersey. The EPA also used Canal Street as a cut off for its voluntary residential clean up program. However the one million tons of dust unleashed by the collapse spread out over a large area, an area that still has not been scientifically measured.

Q: I don’t understand why Mayor Boomberg’s name wasn’t mentioned in the entire article today. There was not one word about him or his administration in this entire article. The mayor has proved in five years that he is concerned only with the lungs of people who smoke and not those of us whose lungs were smoked out that day.

-- Christine

A: The article dealt with the federal response to the health crisis. Because the attack on New York was considered an attack on the United States, many believe the response to the health crisis should also be a national response. However, the city’s long delay in releasing clinical guidelines for doctors, as well as its attempt to fight lawsuits brought by thousands of responders, were mentioned in this article, and covered in previous ones.

Q: Buried in the article it mentions that uniformed personel have health insurance in addition to free treatment through Mt. Sinai and other programs already. The real tragedy are those non-city workers who are undocumented, including immigrants, who cleaned the buildings and the site. They don’t have powerful unions advocating for them and thereby bringing out the politicians.

-- Bill

A: In its most recent health study, released today, Mt. Sinai reported that 40 percent of the responders it has screened either never had insurance or have lost it since they became too ill to work. The New York Committee on Occupational Safety and Health, to name just one organization, has been advocating on their behalf.

Q: I was deployed with FEMA from California two weeks post 9/11. I worked the pile at Ground Zero for 2 days and remember the smells and smoke from the fires still burning underground. I went out from working as a paramedic in August of 2003 from a stress injury, and have subsequently had a huge decrease in my overall energy, ability to heal. Just recently I had a sinus infection that lasted over three months. I don’t smoke, and I try to take care of myself, but since returning from 9/11 much of my overall physical health is diminished... I’ve been keeping up with the reports about various firefighters, police, EMT’s and medics or anyone else who worked the pile, having serious respiratory consequences and even death. I’d like to hear more about what happened to other workers there and what other types of health issues they are dealing with.

-- Dave Moorer, EMT-P

A: You’re right about there being many other workers who came from outside the New York area to help, and who have become sick because of their work on the pile. Dr. John Howard, the national coordinator for 9/11 health issues, has said that his work is hampered because there is no list of responders, and many of those from other states have not been identified. The $52 million appropriated by the federal government for health care may include a national program, but details are yet to be worked out. In the meantime, all medical experts involved in 9/11 health issues encourage all responders to be screened, and those who have already been examined once to return periodically for monitoring. Information is available at www.wtcexams.org.

Q: I was a senior at Stuyvesant High School and witnessed the Towers’ collapse five years ago. Prior to September 11, I was always healthy and rarely suffered from respiratory problems. After 9/11, I experienced increased bouts of severe bronchitis and other sinus infections. Over the years, my classmates have had similar experiences. As the consequences of breathing that toxic air will not be realized for many years to come, what will the city do for us and so many other brave volunteers who worked at their own risk to restore lower Manhattan?

-- Jessica

A: On Tuesday Mayor Bloomberg announced a screening and treatment program that will operate at Bellevue Hospital starting in January. It will be open, according to Mr. Bloomberg, to anyone who was sickened by exposure to trade center dust and fumes. The Red Cross also supports several programs that provide help in dealing with mental health problems related to the disaster. You should be able to get in touch with both. However, if you have not already signed up to participate in the World Trade Center Health Registry, which is run by the city with federal assistance, it is too late to do so. More than 71,000 people affected by the trade center disaster who have already signed up will have their health monitored for years.

Q: I, too, wonder about possible health consequences for people who were in the area on 9/11 and returned to work the following week. I was on park row when the first building fell, and returned to work each day for months to a desk covered in grey dust. The ruins of the WTC were trucked to and loaded onto barges across the street from my office for months. My apartment, just above 14th street, was coated for weeks with a green, slimy dust. Why has no one even spoken about the possible effect on those who work downtown?

-- cynthia

A: The contamination of indoor spaces has been a thorny problem since the first days after the towers fell. Initially, officials told residents and workers returning to their homes and offices that the dust could be cleaned up simply, using wet rags and vacuums. Later, the Environmental Protection Agency offered a free voluntary residential clean-up program. Thousands of apartments were cleaned, but because the program was voluntary, it was less than effective. If all of the apartments in a residential building were not cleaned, along with the public spaces and the heating and ventilation system, cleaned apartments could be recontaminated. The E.P.A. was forced by Sen. Clinton and the New York delegation to return to lower Manhattan to retest the cleaned apartments to make sure they were not still contaminated. That effort developed into a broader program to offer a more comprehensive cleaning program to residents in lower Manhattan and part of Brooklyn. But that effort broke down after two years of debate, and the E.P.A. has yet to offer an alternative plan.

Q: It’s my understanding that the towers were filled with asbestos for insulation. Even with the .8% of asbestos in the dust, how does that compare to the safety levels for aesbestos that have already been established? And how long was the exposure to this .8%?

National Institute for Cancer: http://www.nci.nih.gov/cancertopics/factsheet/Risk/asbestos#q7

Are the doctors testing specifically for aesbestos in the patients with respiratory problems?

-- Erin

A: The doctors at Mt. Sinai Medical Center, which is part of a consortium of hospitals in the area offering screening and monitoring, are not testing specifically for asbestos in the lungs. Asbestos cannot be detected in urine, blood or feces. Chest x-rays would not show the presence of asbestos either, although they could be used to detect the early formation of a tumor. Cancers caused by asbestos, like asbestosis and mesothelioma, can take 30 years to develop. The Environmental Protection Agency, as it monitored outdoor air in lower Manhattan in the days and weeks after 9/11, found the levels to be below industrial standards for exposure to asbestos. The dust itself was found to contain asbestos, though less than was feared initially. (The use of asbestos for insulation was prohibited after construction on the towers began in the early 1970s. Mineral slag wool replaced the asbestos coatings, but the asbestos that had already been applied was left in place.) There is still a great deal of controversy about the presence of asbestos in the dust and the danger it presents.

Q: I thought it was extremely odd that the article failed to mention the (false) assurances from Christine Todd Whitman, head of EPA, that everything was safe. These reassurances were contradicted by EPA’s own reports, not released because the White House wanted to keep them secret. In February, a judge quashed Whitman’s attempt to evade responsibility, stating that her actions “shocked the conscience.” I feel sure that, had the danger been revealed, precautionary steps would have been taken to protect worker health. Instead, the Federal government—and Christine Todd Whitman and George W. Bush in particular—spread false information that greatly increased the health damage.

Shouldn’t this have been at least alluded to in the story? That the casualties were made greater by this immoral, unethical, and illegal action?

-- Michael Ham

A: Ms. Whitman’s statement has been reported many times in The New York Times. Although you are right, and we could have brought it up again, or alluded to it, I attempted to try to get past that by focusing on the federal government’s belated recognition of the problem and its actions since then. As we continue to cover the law suit that you make reference to, which was filed by residents against Ms. Whitman and the E.P.A., we undoubtedly will have to refer to it again.

Q: In late Nov. 2001 until May 2002 I was assigned to work at ground zero by my employer Butler Fleet Services to supervise the maintenance of the Verizon ground fleet. My office location was approx. 2 blocks from ground zero. Since then I have developed breathing problems, which I never had before. It gets worse every year. Since I live in PA. I would like to know if there is any help I can get here. Thank you for your time.

-- Joe Mohr

A: If you haven’t already done so, you should get in touch with the World Trade Center Medical Monitoring and Screening Program at Mount Sinai Medical Center (888-702-0630.) They will let you know if you meet the eligibility requirements for the screening and monitoring program (as it appears that, based on your work there, you certainly do). If you cannot make it into Manhattan for the screening, they will recommend one of the other medical centers in the screening consortium supported by federal funds. Unfortunately, there is no specific clinic in Pennsylvania. You may also want to reach the Association of Occupational and Environmental Clinics, a non-profit group that can make a health referral in your area. Their number is (888-347-2632). And one last suggestion, the Red Cross does have 9/11 support groups in Pennsylvania. You can call the client assistance center at 877-746-4987 or check their website (and click on "Resources" located in the middle of the page.

Q: I’m a first responder who spent nearly 900 hrs mostly at Staten Island Landfill and some time at Ground Zero. Last year I was diagnosed with thyroid cancer and diagnosed earlier this year with multiple myeloma. I’ve heard many times that cancer takes maybe 20 years to develop but in less than a year I have two. I’ve also read there’s at least 300 first responders with cancer as well. Will there be any studies on cancer and 9/11?

-- Reggie H.

A: First things first. If you haven’t already been screened by the World Trade Center Medical Monitoring and Screening program at Mount Sinai (888-702-0630) you should do so as soon as possible. The doctors there continue to encourage anyone who worked on the pile or at Fresh Kills to enroll. As for cancers, which is a very important question, doctors are concerned about the presence of several carcinogens in the dust that may cause problems in years to come. Some medical experts believe that the unique combination of toxic material in the dust and smoke may have worked to accelerate the usual period over which cancers develop, but that theory is not universally accepted. Doctors at Mount Sinai continue to believe that it will be a number of years before anything scientifically sound can be said about cancers. However, they are preparing to launch a special statistical tracking project that will collect such information and, over time, compare incidence rates among workers who labored in the rescue and recovery operations with national rates.

Q: It is ironic that all the health concerns raised by the NYC Department of Health have focused on first responders and residents of NYC who lived in Manhattan south of Chambers Street on 9/11/01.

As I recall that tragic Tuesday in 2001 the clouds of smoke caused by the two planes crashing into the WTC were blown south across the New York harbor and lingered over the borough of Brooklyn.

In recalling this image I wonder why none of the health surveys have focused on the residents of Brooklyn and if there are any epidemiological studies regarding the potential increased health risks experienced by Brooklynites? Are you are aware of any studies or health department policies that have addressed this situation?

-- Arnold Korotkin

A: The Bellevue Hospital World Trade Center Health Impacts Treatment Program screens and treats residents of lower Manhattan who were exposed to trade center dust and fumes (212-358-0295). Dr. Joan Reibman, who heads the clinic, has said that a study done in collaboration with the New York State Department of Health found a four-fold increase in dry cough, and a six-fold increase in wheezing among residents who were screened. She said that while the health of some of the residents has improved, the ongoing situation is unclear, and more studies need to be done. However,I am not aware of any such studies for Brooklyn residents, although I have heard from some residents who have complained about respiratory problems similar to those experienced by workers at ground zero. Mayor Bloomberg Tuesday announced an expansion of The Bellevue Hospital World Trade Center Health Impacts Treatment Program, which will have additional money to screen and treat any residents of Brooklyn who were exposed to the dust and fumes.

Q: I was a volunteer at St. Paul’s from 9/17 until it closed. I remember clearly that a woman from OSHA came and said she was told masks were not needed but then proceeded to give me a mask and show me the proper way to use it and store it so as to not pick up dust. I worked the night shift and it would “rain” grit so that we would spit out black sputum and our teeth were “sandy.” I used what masks we had but they were not available in the early days except if you brought your own from a hardware store. Many “rainy” nights, I walked the perimeter handing out paper masks to police officers and National Guards at their posts. What bothers me is the lie. Anyone with any training or who experience gritty teeth, can make a direct correlation. I had “WTC cough” the entire 9 months. Luckily, aside from some reactive airway problems in very hot or very cold air, I have been ok to date. I feel that I did what needed to be done with the knowledge that there was personal risk, but the lie bothers me a lot.

-- Andrea

A: You bring up an issue that has caused a great deal of consternation among a large number of people. As was often the case in the early days after the attack, information about the dust and the use of masks was confused at best, contradictory at worst. An article of mine that was published in The New York Times on June 5 lays out many of the details about the use of air masks at ground zero. But in brief, in order to make sure the recovery work could proceed as quickly as possible, the Occupational Safety and Health Administration, which is charged with responsibility for workplace safety, was put into a consulting position at ground zero. It was not enforcing compliance with workplace regulations, including those requiring respirators. The contractors working for the city agreed to follow existing workplace safety regulations, and for the most part the mutual cooperation agreement worked to keep the chaotic worksite free from serious injuries and accidental deaths. However, when it came to the use of respirators, the system seemed to break down. In the early days after the towers collapsed, when the dust was thickest and the need for respirators greatest, there weren’t enough respirators available. You might have seen photographs of firefighters, police officers and union workers wearing flimsy paper masks. But they were essentially useless against the dust. When the more effective cartridge-type respirators became available, workers found them difficult to use because they impeded their ability to communicate. Many workers believed that the Environmental Protection Administration’s statement that the “air was safe to breathe” meant that respirator masks did not need to be worn. Despite the fact that more than 150,000 respirator masks ended up being distributed, many workers did not use them. And of course, residents and office workers returned to Lower Manhattan while dust and smoke still filled the air.

Q: I am a registered nurse and certified case manager and am interested in pursuing an opportunity to work with this population by providing case and disease management services. We utilize certified case manager RNs who contact the patients and become their health advocate, also working as physician liaisons and assist with symptom and disease management. The overall goal is to provide case management services assuring the patients receive the resources and education they need in order to maintain the optimal level of wellness. We currently work with many patients with chronic obstructive lung disease and asthma and have had many success stories and improved outcomes. Is there a contact name that you could provide? It seems there is a great need here as many of these individuals do not appear to have insurance and therefore are not receiving the care they so deserve.

-- Christine

A: One place you might consider is the New York Committee for Occupational Safety and Health (NYCOSH), which has reached out to help many of the ground zero workers who either have no insurance or who have lost their insurance because they cannot work. David Newman, an industrial hygienist at NYCOSH, said he would be happy to work with you. You can reach him at 212-227-6440 extension 16.

Q: Just for the record: FEMA provides no medical insurance coverage or sick-leave for its DAE (Disaster Assistance Employees), the on-call “intermittant” employees who make up the vast majority of the FEMA workforce. FEMA workers who participated in the 9/11 disaster response/recovery operation in NYC have been asked, periodically, to participate in a post-9/11 “study” to benefit “future generations”. Unfortunately, what I really care about is my generation- the folks like my husband, myself, our coworkers, and friends who are still alive, many of whom still have no medical insurance. I love my job, and I love the agency I work for, and I left the 9/11 operation with a lung infection, and wound up taking my dog’s antibiotic for 3 weeks because I had no medical insurance. A NYer, I was also turned down for NYC’s “victims services” disaster counseling because I had not “worked at the pit” - I had spent 5 months working, for the most part, at the Piers and downtown with disaster survivors and their families, and crying and yelling myself to sleep most nights in sheer frustration. Disaster workers are highly motivated people, but they get sick, and they work sick, week after week, month after month, because they have no sick-leave benefits: that’s reality. You don’t work, you don’t get paid. The buildings we work in are often contaminated- that’s reality, too. “Air scrubbers” are expensive; in NYC they were deemed too expensive to install in the facilitities. There were dozens of cases of lung infections, eye infections, shingles, and skin infections just among my small group of coworkers following Katrina & Rita. And though tsk-tsking lip-service is abundant, no one is actually DOING anything to provide them with medical coverage or sickleave. Is this truly “cost effective”?

-- Elisse Clark

A: In all the commotion over ground zero, federal workers have received little attention, although their needs are apparent. The federal government did begin a World Trade Center Federal Responder Medical Screening Program, but it was shut down soon after it began because it proved to be inadequate. The program has now been revamped. Any federal employee who worked at ground zero or the Staten Island landfill for at least one shift between September 11, 2001 and September 10, 2002 is eligible. The contact number is (866) 214-2040 or on the website at https://wtcophep.rti.org. The cleanup of office buildings downtown remains an open issue. Previous attempts to decontaminate buildings have been incomplete, or improperly done. Many buildings have never been cleaned. The Environmental Protection Agency was considering a plan to test a sample of office buildings in lower Manhattan and Brooklyn to determine whether they are still contaminated, but the plan was scuttled when the agency could not come to agreement on how to test for trade center dust. As of now, there is no plan to test or clean office buildings.

Q: Are you aware of any similar programs for residents who lived near the Pentagon? I lived a couple of blocks from the Pentagon in the Crystal City neighborhood from 2000-2002. On September 11, my apartment filled with smoke from the Pentagon. For weeks afterward, it reeked of the awful smells of that day. If I recall correctly, t was about 3 weeks afterward that the company that owned our building pumped a cleaner/deodorant through the duct system. I have subsequently suffered reduced lung function and sinus infections.

-- Brian Chapin

A: I am not aware of any screening or monitoring program for Pentagon-area residents. The National Institute for Occupational Safety and Health, which funds the New York program, does not support anything like it in Washington. As far as we know at this point, the collapse of a part of the Pentagon struck by the airliner did not release the same kind of dust cloud as the trade center. Nor was the concrete pulverized in the same way as happened with the twin towers. However, the Red Cross runs a 9/11 support group in the Capitol area. It can be reached by calling the Client Assistance number at (877) 746-4987.

Q: Dear Mr. DePalma, you state in one question, if you have not already signed up to participate in the World Trade center Health Registry, which is run by the city with federal assistance, it is too late to do so... If the federal government was lying and telling everyone it was safe, why shouldn’t people who have developed problems in later years, who have documentation about where they lived or how they worked on the clean up of the Trade Center, be able to sign up now and participate in the World Trade center Health Registry?

-- Thomas O'Brien

A: It is important to understand that the WTC Health Registry is not designed to provide any type of medical care for anyone. Rather, it is simple a listing of people who were exposed to the dust, fumes and traumatic events of 9/11. The Registry will track their medical history over time, but in most cases, the 71,437 people on the list will never actually be examined by a doctor for the registry. Their initial, self-reported medical history is being updated now but this too will consist of self-reported answers to the registry’s questionnaire.

Q: I don’t think any of the posters have yet addressed the motivation behind the EPA’s decision to lie to us. In my opinion, the government was backed into a corner by the imperative need to get the NYSE back in business. Evacuating the area would have caused a global economic disaster of unimaginable proportions.

-- A.C.

A: A comprehensive report by the Office of the Inspector General found that Christie Whitman and the Environmental Protection Agency did not have sufficient evidence at hand on Sept. 18, 2001, to have made the general statement that the air in lower Manhattan was safe to breathe. The I.G. report also found that press releases prepared by the EPA were reviewed by the White House, which it claimed had at least indirectly influenced the wording of that statement by removing some cautionary language. Returning lower Manhattan and the financial district to some sense of normalcy was indeed an important policy decision, with wide-ranging economic consequences. But many of those who have become ill feel that the human consequences of that act had been overlooked.

Q: While the Towers were being built, I was Assistant Director of the Division of Industrial Safety of the NY State Dept of Labor. When we became aware that Asbestos was being sprayed on the inside of the panels which formed the face of the buildings, we requested that protection be provided for the construction workers in the buildings. We were informed that we had no jurisdiction since the Port Authority was not subject to the laws of NY or NJ or the City of New York. The NYC Bldg Dept and the NYC Fire Dept were also aware that the bldgs were in violation of NYC Codes. The “Dust” referred to in the Media was Asbestos.

-- Harry Silbereberg

A: As the World Trade Center was being built in the late 1960's and early 1970's, scientists learned that asbestos fibers contained in fireproofing for steel beams could cause cancer in workers. The builders of the center anticipated that there would be a ban on the use of asbestos, and stopped using it by the time they reached the 40th floor of the north tower, the first one to go up. In place of asbestos, the builders substituted a new material known as mineral wool, which was essentially rock particles held together by cement. When the towers collapsed, scientists at first feared that the huge cloud of dust might have contained as much as 20 percent asbestos. An analysis of the dust done by the Environmental and Occupational Health Sciences Institute at Rutgers University found that bulk samples contained less than 3 percent asbestos. Individual samples taken from three specific locations were found to contained less than 1 percent asbestos. Because the dust was made up of so many different materials -- basically everything contained in the two buildings and the pulverized buildings themselves -- the samples very widely. For more information about the use of asbestos in construction of the World Trade Center, you can check this article from The New York Times in September, 2001.

You are right about the special status of the Port Authority of New York and New Jersey. Because it was formed by an interstate compact, it is not subject to most local regulations. The New York City Department of Buildings did not have authority to review the construction plans, and it was only after the first attack on the building in 1993 that the Port Authority agreed to file some building plans with the city. The Occupational Safety and Health Administration, which oversees workplace safety, was created in 1971, after construction of the center had begun.

Q: What is name and docket number of the class action suit by the responders against NYC?

-- Joe Carson, P.E.

A: Judge Alvin K. Hellerstein of the United States District Court ordered that thousands of individual suits filed in the World Trade center case be consolidated under a single Master Complaint. The docket number is 21 MC 100 (AKH) and it was filed Feb. 2, 2005.

Q: Do you know of any means of sharing the medical wisedom of those treating uniformed first responders with non-uniformed, medically impaired, residents and workers of the WTC area? The governmental lack of action in addressing the medical difficulties of first responders, is amplified many fold , by the lack of response in addressing the problems of ordinary persons who were exposed, over months , to toxic smoke and dust.

-- joan giummo

A: I know of no authoritative and comprehensive guide of the type you are seeking. However, several of the peer-reviewed medical studies that have been done on the workers who labored in the rescue and recovery operations at ground zero have been published by Mount Sinai and the Centers for Disease Control. You can find several at www.wtcexams.org.

Q: Did the Environmental Protection Agency test air quality in lower Manhattan in the days immediately following 9/11? If so, did they publish a result of those tests? I remember hearing EPA assurances that everything was fine but I do not recall hearing of any specific test results from September 2001.

-- Gilbert Johnson

A: The Environmental Protection Agency’s Region 2 office has a listing of its efforts available on its website.

Q: Why is the federal government, who stated that the air at ground zero was safe to breathe, not being aggressively investigated? Also, have there been any federal lawsuits filed by victim’s families related to this matter that may lead to investigations?

-- Paul

A: Some 8,000 workers and their families have sued the city and the big contractors working for the city, claiming there was disregard for workers health in the rescue and recovery operations. The suits have been consolidated into a single Master Complaint before Judge Hellerstein in Federal Court. The city has filed a motion to dismiss the suit, claiming it is protected from such suit by immunity laws in state laws regarding official responses to disasters.

A Class Action law suit against the E.P.A. and the Department of Health has also been filed on behalf of residents, office workers and school children who were exposed to the smoke and fumes from the pile. The docket number in that case is 04Cv1888, and it is before Judge Deborah A. Batts of Federal District Court in Manhattan.

Q: How does one go about getting screened by Mt. Sinai hospital as part of their program. Our staff was involved in portions of the clean-up for about the first 3 weeks after Sept. 11, 2001. To my knowledge, no one here was ever contacted about receiving screenings.

Do you have a contact name and number that I could call to get this information?

-- Connie Fishman

A: You can register by calling the Mount Sinai screening and monitoring program at (888) 702-0630.

Q: I did not live in NYC until 2005, but I have been working around the corner from the WTC site on Broadway for the past year and a half. Could there possibly be any effects from the air this late in the game? With this part of the island surrounded so closely by water and the resulting air currents, I don’t imagine so; but the deconstruction of the Deutsche Bank building, which is right next door, does concern me somewhat.

-- Meredith

A: At this time, five years later, most of the dust is no longer a concern, although as you point out the deconstruction of the former Deutsche Bank building and other structures near ground zero has the potential for releasing more hazards. Those projects are being monitored by city and federal environmental officials. Of great concern now is the question of indoor contamination, especially in apartments and offices that have never been cleaned or were decontaminated improperly. Federal efforts to address the problem have been stalled since last December.

Q: How can people, who were exposed to the dust from the World Trade Center because they worked in the area, register to be tested and monitored at Bellevue Hospital?

-- Kathryn

A: The phone contact for the Bellevue Hospital World Trade Center Health Impacts Treatment Program is 212-358-0295.

Q: In the days following 9/11, my employer urged employees to volunteer at the site assisting the Red Cross. I did and have never felt any ill effects since. I also lived below 14th St. and remember the air quality being horrible in the weeks afterwards. Though I am entirely symptom free, do you recommend participating in any studies to monitor possible long term effects?

-- Leslie Steven

A: You might consider getting in touch with Bellevue Hospitals WTC program at 212-358-0295.

Q: I was across the street from the first tower when it started to fall. I and some others immediately ran into a building. A few minutes later we went to the back of the building to leave by the rear exit. When we opened the door there were many largish white things floating in the air. We took one or maybe two gulps of air before we closed the door. Then, a minute or two before the second tower fell we ran out with towels covering our mouths. My eyes burned for a few months but besides that I have not had any problems. I worry though about those one or two gulps of air with the large white things. Can you give me any information or guidance as to what I should be thinking/doing?

-- BA

A: Most of the one million tons of dust released by the collapse of the towers consisted of large particles like those you describe. Analysis of the dust found them to be made up mostly of pulverized concrete. That made them very alkaline, or caustic, and because of that they were likely to cause dry coughs and burns. But because the particles were so large, doctors feel there was little chance that they made their way into the lower airways of the lungs. Still, because the concentration of dust in the air was so high, and because many people were not wearing respirator masks and were working hard, it was possible for some of the large particles to work their way deep into the lungs.

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