Before the Committee on Environment and Public Works
United States Senate
Bioterrorism: The Role of CDC and ATSDR in Remediating Contaminated Buildings
Patrick J. Meehan, M.D.
Division of Emergency and Environmental Health Services,
National Center for Environmental Health,
Centers for Disease Control and Prevention
Department of Health and Human Services
Good morning, Mr. Chairman and Members of the Subcommittee. I am Dr. Patrick Meehan, Director, Division of Emergency and Environmental Health Services, Centers for Disease Control and Prevention (CDC), Department of Health and Human Services (HHS). Thank you for the invitation to discuss CDC=s and HHS=s Agency for Toxic Substances and Disease Registry=s (ATSDR) role in supporting the Environmental Protection Agency (EPA) in remediating anthrax-contaminated workplaces. My division includes CDC=s National Pharmaceutical Stockpile (NPS) as well as coordination of emergency preparedness and response activities under the Federal Response Plan.
Today, I will update you on the intentional release of anthrax and the number of exposed and affected persons, as well as summarize CDC and ATSDR's efforts to identify exposure, prevent anthrax disease, and monitor the health of those known to be exposed. I will also discuss CDC and ATSDR's collaboration with the EPA to assist in remediating contaminated buildings and protecting the health of workers in those buildings.
I would like to begin by emphasizing the importance of remediating all anthrax-contaminated worksites. CDC and ATSDR have worked, and will continue to work diligently along with EPA and our federal, state, and local public health partners to help achieve this goal. Every worker in the United States deserves a safe and healthy workplace. In the past two months, terrorists have used anthrax spores to disrupt, displace, and even infect American workers. One phase of the fight against terrorism is to remediate contaminated workplaces and protect the health and safety of American workers who need to return to their jobs. We must also protect those workers whose job it is to investigate and clean these work places. These are the people who have been on the front lines of this battle, and they deserve our help and support.
As you are aware, many facilities in communities around the country have received anthrax threat letters. Most were received as empty envelopes; some have contained powdery substances. However, in some cases, actual anthrax exposures have occurred. These cases have been identified in Florida, New Jersey, New York, Washington, DC, and Connecticut. This is the first bioterrorism-related anthrax attack in the United States, and the public health ramifications of this attack continue to evolve. In collaboration with state and local health and law enforcement officials, CDC, ATSDR, and the Federal Bureau of Investigation (FBI) are continuing to conduct health investigations related to anthrax exposures. During this heightened surveillance, cases of illness that may reasonably resemble symptoms of anthrax have been thoroughly reviewed. The public health and medical communities continue to be on a heightened level of disease monitoring to ensure that any potential exposure is recognized and that appropriate medical evaluations are given. This is an example of the disease monitoring system in action, and that system is working.
The Department of Health and Human Services= (DHHS) anti-bioterrorism efforts are focused on improving the nation's public health surveillance network to quickly detect and identify the biological agent that has been released; strengthening the capacities for medical response, especially at the local level; expanding the stockpile of pharmaceuticals for use when needed; expanding research on disease agents that might be released, rapid methods for identifying biological agents, and improved treatments and vaccines; and regulating the shipment of hazardous biological agents or toxins.
As the Nation=s disease prevention and control agency, it is CDC=s responsibility on behalf of DHHS to provide national leadership in the public health and medical communities in a concerted effort to detect, diagnose, respond to, and prevent illnesses, including those that occur as a result of a deliberate release of biological agents. This task is an integral part of CDC=s overall mission to monitor and protect the health of the U.S. population.
Since the intentional release of anthrax spores, one of the areas on which CDC and ATSDR have focused is the identification and cleanup of contaminated facilities. We have refined methods for environmental sampling to assess whether anthrax contamination had occurred; in buildings that has meant sampling of air and surfaces. CDC and ATSDR have issued recommendations on how to conduct environmental sampling and how laboratories should analyze those samples. We also recommended environmental sampling strategies to characterize the extent of exposure and to guide cleanup. We issued recommendations to protect first responders, investigators, and cleanup personnel. As buildings were identified as contaminated, we provided technical input to EPA and others tasked with cleanup to determine where remediation was necessary. These recommendations have been widely disseminated to federal, state and local health and environmental agencies, and are available at CDC=s bioterrorism website (http://www.bt.cdc.gov).
EPA has devised strategies for remediation and has gained much experience through its activities to date. Disease experts at CDC are developing strategies to prevent the spread of disease during and after bioterrorist attacks. Although there are some data on chemical disinfectants in the scientific literature, there are no historical data that indicate the best way to eliminate spores from an office building, or to disinfect a sorting machine. The ability of a disinfectant to kill an anthrax spore is dependent upon time of contact and concentration and is mitigated by the amount and composition of material through which it must penetrate to get to the spore. For many of the clean-up methods being used to kill anthrax spores, we will not know their effectiveness until we go through the process. EPA understands this and has sought help from a variety of sources, including CDC and ATSDR, to ensure that the appropriate indicators are used and that post-sampling strategies are adequate.
With regard to the effectiveness of cleaning, even our most exhaustive sampling strategies will not identify every spore. It is unlikely that any cleaning strategy will kill every spore. However, the EPA should be able to clean and re-test to the point where we all are comfortable that spores have been killed or removed from surfaces where human contact is likely to occur. A range of sampling methods and strategies should be used to ensure the safety of building occupants.
In heavily contaminated areas, such as Senator Daschle=s suite and the Brentwood postal facility, fumigation is being proposed as the method of clean-up. The use of fumigants is a potential hazard for clean-up workers, those in areas adjacent to the buildings, and those that must re-occupy the building. A fumigant that is effective at killing spores is, of necessity, a highly toxic agent. The protection of workers during the fumigation process is a matter of good industrial hygiene. EPA, CDC, and ATSDR are working together to ensure remediation workers are protected during the fumigation processes. EPA works with local public health agencies to ensure that people in the area but outside of the building being fumigated are notified and kept at a safe distance.
With regard to the safety of those who will re-occupy the building, it is important to determine both that the area is clear of the fumigant and that there is no health risk. Again, CDC, ATSDR, and the Occupational Safety and Health Administration (OSHA) have developed exposure limits for fumigants, and detection methods are available to determine when any residual fumigant is well below established limits. After buildings are cleaned and post-cleaning environmental sampling has been conducted, CDC and ATSDR are committed to providing technical input to the incident command and other experts to determine whether the building is ready for re-occupancy.
CDC has been addressing issues of detection, epidemiologic investigation, diagnostics, and enhanced infrastructure and communications as part of its overall bioterrorism preparedness strategies. Based on federal, state, and local response in the weeks following the events of September 11 and on recent training experiences, CDC has learned valuable lessons and identified gaps that exist in bioterrorism preparedness and response at federal, state, and local levels. CDC will continue to work with partners to address challenges such as improving coordination among other federal agencies during a response and understanding the necessary relationship needed between conducting a criminal investigation versus an epidemiologic case investigation. These issues, as well as overall preparedness planning at federal, state, and local levels, require additional action to ensure that the nation is fully prepared to respond to acts of biological and chemical terrorism.
In conclusion, CDC and ATSDR are committed to working with other federal agencies and partners as well as state and local public health departments to ensure the health and medical care of our citizens. We are committed to continuing our partnership with EPA to ensure that the best public health information is coupled with the best ideas for how to remediate contaminated facilities. We need to improve sampling methods and equipment. We must learn from this experience and continue to assist the EPA in determining the best ways to remediate different types of workplace environments having different amounts of anthrax contamination.
Thank you very much for your attention. I will be happy to answer any questions you may have.