Statement by
Diane Porter, Deputy Director
National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Department of Health and Human Services

Hearing: Assessing September 11th Health Effects: What Should Be Done?
before the
The Subcommittee on National Security, Emerging Threats and International Relations, Committee on Government Reform, United States House of Representatives

October 28, 2003

Mr. Chairman, Representative Maloney, and members of the Subcommittee, my name is Diane Porter, and I am Deputy Director for Management with the National Institute for Occupational Safety and Health (NIOSH), part of the Centers for Disease Control and Prevention (CDC) within the Department of Health and Human Services. CDC's mission is to promote health and quality of life by preventing and controlling disease, injury and disability. NIOSH is a research institute within CDC that is responsible for conducting research and making recommendations to identify and prevent work-related illness and injury.

I am pleased to appear before you today to provide testimony on behalf of CDC and our sister agency, the Agency for Toxic Substances and Disease Registry (ATSDR). My testimony will address CDC and ATSDR activities related to the health impacts on rescue, recovery and restoration workers and volunteers at the World Trade Center (WTC) site; office workers, residents, and school children who were in the vicinity of the site on September 11; and workers at the WTC recovery operations on Staten Island. As you know, CDC provided extensive emergency assistance during the initial months following September 11th, providing technical assistance to the Federal Emergency Management Administration (FEMA) and to the New York City Department of Health and Mental Hygiene to better characterize the acute exposures and to make recommendations for development of a comprehensive protection program for the rescue workers.

My testimony today will focus on CDC and ATSDR activities following this emergency response including CDC's efforts to respond to the needs of workers and volunteers regarding the potential short- and long-term health effects of their exposures at the WTC site. I also will describe CDC and ATSDR's activities to evaluate physical and mental health impacts on the wider community of persons who were living, working or attending school in the vicinity of the WTC site.

Mr. Chairman, I would like to express my appreciation to you, to Representative Maloney, and to the members of the subcommittee for holding this hearing to address the health concerns and well-being of the community surrounding the World Trade Center site, including and the brave responders and front-line workers who stepped forward in response to the attack on September 11, 2001. CDC, ATSDR and the Department of Health and Human Services share your concern for the community and for the workers who responded so courageously in our country's time of great need.

Addressing Health Needs of WTC Responders

CDC provided technical assistance in occupational health to the Fire Department of New York (FDNY) in the evaluation of approximately 350 fire fighters three weeks following September 11th. This evaluation revealed that few fire fighters were wearing adequate respiratory protection during the initial period of response to the disaster when exposures were highest. It also demonstrated a decrease in quality in the fire fighters' pulmonary function compared to the routine pulmonary function tests that were done over the course of the two years prior to September 2001.

CDC's environmental health laboratory also measured 110 chemicals in blood and urine from these fire fighters. The study found the levels of chemicals in the exposed firefighters were generally low and not outside the ranges found in the general population. Although levels of some of the chemicals analyzed showed statistically significant differences between the control and exposed firefighters, these differences were generally small. The study was done in collaboration with the FDNY.

During the weeks following September 11th, CDC physicians were in contact with the FDNY medical staff and with other community-based occupational health providers who began reporting concerns about the health problems they were finding in workers and volunteers who had been at the WTC site. CDC helped establish an informal network of occupational medicine specialists who discussed their findings and began to better define the type and severity of health problems they had seen. This informal network, with Mt. Sinai School of Medicine's Center for Occupational and Environmental Medicine's occupational medicine physicians in the lead, wrote a guidance document aimed at assisting community-based physicians with the appropriate evaluation of these patients. The work of this initial network of physicians helped lay the groundwork for creation of a comprehensive medical screening program.

Health Hazard Evaluations

In November 2001, the Department of Health and Human Services asked CDC to look into health concerns of employees working in the Federal Building near the WTC site. A month later, in December 2001, CDC also was contacted by a group of labor unions who represented various city and state workers employed in buildings near the WTC site. These workers included the teaching and support staff at Stuyvesant High School and the Borough of Manhattan Community College; New York City employees working at an office building on Rector Street; New York State workers employed in an office building on Broadway; and employees working in the New York City bus and subway divisions of the Metropolitan Transit Authority.

In response to these requests, CDC conducted a series of health surveys among workers to evaluate the rates of physical health and mental health symptoms among these workers. CDC compared the responses of WTC-area workers to those of similar workers either outside of NYC (for federal workers) or in New York City but more than five miles from the WTC site. The worker evaluations that CDC conducted found elevated rates of upper and lower respiratory and gastrointestinal symptoms and symptoms consistent with depression and post-traumatic stress disorder in the WTC-area workers compared to other similar workers. These symptoms were still present two to six months after September 11th. In reports provided to employer and employee representatives, CDC recommended that employers develop programs that would provide easy access to physical and mental health services and create a supportive and therefore less stressful work environment.

Baseline Medical Screening

In January 2002, CDC received funds from FEMA to award two grants: $4.8 million to the New York City fire department to conduct baseline medical evaluations for fire fighters who responded at the WTC site and $2.4 million to the New York State Department of Health to conduct such evaluations for New York State employees who responded at the WTC site in the course of their jobs.

Subsequently, also in 2002, Congress provided $12 million to CDC for baseline medical screening of emergency services and rescue and recovery personnel who responded to the events of September 11th, and who were not otherwise covered by the baseline screening programs being conducted by the FDNY and the New York State Department of Health. CDC awarded a contract to Mt. Sinai School of Medicine's Center for Occupational and Environmental Medicine to establish this program. The Mt. Sinai staff created a consortium of occupational health clinics to provide screening services to workers and volunteers living throughout the New York City metropolitan area and subcontracted with a national network of occupational health clinics for those workers and volunteers who responded from as far away as California and Washington State.

In consultation with CDC occupational health experts, Mt. Sinai developed a comprehensive screening program that, beginning in July 2002, provided a baseline medical assessment as well as assistance with referrals for follow-up care. It was anticipated by Mt. Sinai that the funding provided would cover initial medical screenings for up to 9,000 workers. As of October 9, 2003, the Mt. Sinai-led consortium had screened over 7000 workers. The consortium will continue to conduct baseline screening examinations through March 2004. As relayed in the testimony of Dr. Herbert from Mt. Sinai today, this program has found high rates of persistent respiratory and mental health problems in a sample of workers screened up to two years following September 11, 2001.

Long-Term Medical Monitoring

In 2003, Congress directed FEMA to provide $90 million to CDC to support longer term follow-up medical monitoring for WTC rescue and recovery workers and volunteers, including $25 million designated to be used for current and retired New York City fire fighters. FEMA provided these funds to CDC under an interagency agreement in June of 2003.

In anticipation of receipt of these funds, in May 2003 CDC held a public meeting in New York City to gather input regarding the content and structure of this program. The meeting was attended by individuals representing the medical community, city and state health departments, labor unions, employers, and other federal research agencies such as the Environmental Protection Agency and the National Institutes of Health. Participants identified a number of significant health concerns among the exposed workers, particularly, respiratory and mental health. CDC will be seeking seek additional input from NIH and mental health experts to develop strategies for assessing and monitoring workers to address long term public health concerns and to learn valuable lessons about complex psychobiological impacts and long term recovery.

Meeting participants broadly agreed on several key issues: 1) the 9000 examinations that were currently funded were insufficient to meet the needs of those WTC-site workers still wanting to be evaluated; 2) the longer term program should include multiple, independently funded clinical centers which would offer a choice of follow-up locations without involving the use of subcontracts; 3) the quality of the existing screening program was very satisfactory and therefore currently participating clinical centers should continue to provide services; 4) quality control across multiple programs and over time was essential to the development of a comprehensive program; and 5) determination of the content of the screening program would require careful consideration and input from national experts and should remain dynamic to accommodate evolving needs and new medical innovations.

Based upon the input from the May meeting, CDC supplemented the existing contract with Mt. Sinai with additional funding of approximately $4 million for approximately 3,000 additional baseline examinations. As mentioned previously, these additional baseline examinations will be conducted through March 2004. The $25 million designated for long-term follow-up of New York City firefighters is being provided to the FDNY to conduct this program in coordination with CDC.

With the remaining funds, CDC will award cooperative agreements to provide funding to clinical centers to develop a coordinated, long-term medical screening program. This program will provide those who participated in the baseline screening program a choice of clinical centers to which they may go for long-term follow-up medical services.

The program also will include a centralized data coordination center that will facilitate coordination among clinical centers, assure quality control and allow for periodic review of the screening results in order to adapt the screening protocol to the changing needs of the population over time. This coordinating center will be responsible for evaluation of the program through ongoing evaluation of the quality of collected data, periodic analysis to determine the usefulness of the specific components of the clinical evaluation, and monitoring of feedback from program participants concerning the adequacy of referral and follow-up procedures. It is anticipated that through this funding mechanism, the clinical centers should receive funding to begin the long-term program by March 2004, after the additional baseline examinations have been completed.

The initial medical evaluations conducted by the FDNY, New York State, and the Mt. Sinai-led consortium will provide a baseline to monitor any long-term health outcomes that may be associated with the rescue workers.

Assessing Health Impacts on Workers and the Community

In addition to its activities to assess and address the health impacts on rescue, response and recovery workers, CDC and ATSDR are working to identify the health effects of the WTC disaster on the people who were living, working or attending school in the vicinity of the WTC site.

WTC Health Registry

In collaboration with the New York City Department of Health and Mental Hygiene, ATSDR has established a registry to identify and track over the long term the health of tens of thousands of workers and community members who were the most directly exposed to smoke, dust, and debris from the WTC disaster. The World Trade Center Health Registry was launched on September 5, 2003, with an extensive public outreach campaign. Persons who choose to be included in the registry will be interviewed periodically over a period of 20 years or more concerning their physical and mental health, so that their health may be followed over time. Stringent safeguards are in place to protect the confidentiality of all information collected.

In the nearly two months since it was launched, more than 10,000 people have been interviewed for the registry. ATSDR and the New York City Department of Health and Mental Hygiene estimate that the registry will include 100,000 to 200,000 people, including rescue and recovery workers, office workers, residents and school children, making it the largest health registry of its kind. The registry will be maintained over time by the New York City Department of Health and Mental Hygiene. FEMA provided start-up funds to ATSDR for the development and launching of the registry.

The purpose of the WTC registry is to provide a more complete picture of the health consequences resulting from the events of September 11th. Registry information will be used to identify trends in physical or mental health resulting from the attacks at the WTC and the resulting exposure of nearby residents, school children and workers to dust, smoke and debris. In addition, it will serve as a resource for future investigations and epidemiological and other research studies concerning health consequences of exposed persons from all walks of life, and as a tool for disseminating important prevention and public policy information. The registry, by collecting a broad range of information into a single database, will facilitate coordinated follow-up.

The New York City Department of Health and Mental Hygiene and ATSDR will communicate information concerning physical or mental health impacts to the public and to health care providers so people can make informed decisions about their health care. Information from the registry will be posted quarterly on the WTC Health Registry Web site at www.wtcregistry.org.

Residential Environmental Sampling

ATSDR also worked collaboratively with the New York City Department of Health and Mental Hygiene to determine what hazardous substances were present in the air and dust inside residences near the WTC site. ATSDR and the New York City Department of Health and Mental Hygiene collected air and dust samples in November and December of 2001 from certain units in 30 residential buildings in lower Manhattan and in four residential buildings in upper Manhattan. The sampling revealed fiberglass fibers and low levels of asbestos in some of the indoor dust in lower Manhattan. The upper Manhattan dust samples revealed no fiberglass fibers or asbestos. As a result, the study report recommended that residences in lower Manhattan be thoroughly cleaned with HEPA vacuums, damp cloths, and mops to reduce the potential for exposure. The study concluded that the levels of materials in the dust samples did not pose a potential health hazard if recommended cleaning practices were followed.

Environmental Health Studies

In addition to its occupational health activities discussed earlier, CDC has conducted several environmental health studies in the surrounding community to help determine health effects that might be associated with exposure to smoke and dust from the WTC site.

CDC also has provided funds to the New York City Department of Health and Mental Hygiene and the New York State Department of Health to study asthma and respiratory illnesses following September 11th, including:

  • a study of asthma and respiratory illness-related ambulance dispatches, emergency room visits, and hospitalizations;

  • a study of asthma, other respiratory function, and pulmonary function in residents in lower Manhattan;

  • a survey of asthma, asthma management, and other respiratory illness among preschoolers in lower Manhattan; and

  • a survey of asthma among Medicaid Managed Care enrollees in New York City.

CDC is also supporting a New York Academy of Medicine study showing that about 27 per cent of adults in Manhattan with asthma who responded to a survey done five to nine weeks after the September 11th attacks reported that their asthma had worsened. Adults with asthma were more likely to report their asthma had gotten worse if they had difficulty breathing because of smoke and debris during the attacks or if they were suffering from post-traumatic stress disorder or other symptoms of psychological distress associated with the attacks.

CDC's environmental laboratory is providing analyses of biological samples for an NIH/NIEHS study by Columbia University and Mt. Sinai School of Medicine to evaluate the health effects of exposure to WTC smoke and dust on women who were pregnant on September 11th and on their infants.

In addition, NIH/NIEHS has funded an array of studies on the health consequences of the attacks. NIEHS university grantees have identified the composition and structure of dust particles from the collapse of the buildings, and have determined particle size and the degree of penetration into the airways of those who were exposed. Researchers have also created a public data base that includes both pre- and post-September 11 air quality data; the web address is http://wtc.hs.columbia.edu. Other NIEHS-funded researchers have conducted clinical and epidemiological studies to investigate respiratory abnormalities and post-traumatic stress syndrome in WTC-exposed populations such as firefighters, ironworkers and community residents. Scientists have also identified the symptoms and duration of the "World Trade Center Cough," and determined that most dust particles from the attacks were small enough to penetrate into lung airways, producing caustic effects on the respiratory system.


In summary, CDC and ATSDR are committed to assessing the health effects resulting from the September 11, 2001, attacks on the World Trade Center and identifying the physical and mental health needs of affected workers, residents, and other community members. Thank you for your attention. I am pleased to answer any questions.

Last Revised: October 28, 2003