Chemical Threat Agents
CDC’s Division of Laboratory Sciences (DLS) and National Biomonitoring Program (NBP) provide effective laboratory support for the public health response to chemical threat agents and threats involving selected toxins.
Chemical threat agents can be poisonous vapors, aerosols, liquids or solids that have toxic effects on people. These chemicals can be naturally occurring in the environment or synthetically produced. Chemical releases can be unintentional, as in the case of an industrial accident, or intentional, as in the case of a terrorist attack. Early detection and accurate identification are critical to enable effective treatment and to prevent additional exposures of chemical threats.
Rapid Toxic Screen
The CDC laboratory developed and performs the Rapid Toxic Screen (RTS), a series of tests that analyzes 150 chemical agents in people’s blood and urine. Results of the Rapid Toxic Screen help identify which chemicals were used, who was exposed to the chemicals, and how much of a particular chemical their bodies absorbed. This information is critical to medical and public health personnel managing a chemical public health emergency.
Chemical Emergency Response Team
CDC maintains 24-7 laboratory response capability and can deploy the Chemical Emergency Response Team within two hours of a request to assist with specimen collection, packaging, storage, and shipment. DLS scientists work with state and local officials to collect samples and transport them to CDC where testing can be done to assess people’s exposure to chemical agents. Within 24 hours of arrival in the lab, using the Rapid Toxic Screen, the chemical agent of concern can be identified. Within 36 hours, up to 40 samples can be tested and results reported to decision makers.
Laboratory Response Network for Chemical Threats (LRN-C)
CDC sponsored the creation of the Laboratory Response Network-Chemical (LRN-C), a national network for responding to chemical terrorism and other public health emergencies. LRN-C integrates 55 state and local public health laboratories that operate 24/7 to provide laboratory diagnostics and the surge capacity for chemical emergencies.
As a critical partner, CDC’s Chemical Emergency Response Laboratories provide the LRN-C with a wide range of support services, including:
- Standardized reagents and controls
- Agent-specific protocols
- Lab referral directory
- Secure communications
- Electronic messaging
- Training and technology transfer
- Proficiency testing
- Training and Full Scale exercises
In 2006, the Environmental Health Laboratory helped to figure out the cause of death of at least 50 people in the Republic of Panama. Using advanced laboratory science and innovative techniques, CDC scientists identified diethylene glycol (DEG), a chemical that is used in antifreeze, in cough syrup taken by victims of the poisoning. As a result of the Branch’s work, Panamanian health authorities quickly recalled 60,000 bottles of the contaminated medications, an action that ultimately saved many lives. Following the Panama investigation, the laboratory validated the method for measuring DEG in human urine. This method was used to confirm exposure to DEG in a subsequent case-control study. In the future, the method will be a powerful tool to identify other people who have been poisoned with DEG.
In 2006, CDC and the Agency for Toxic Substances and Disease Registry (ATSDR) were contacted about Kiddie Kollege Day Care Center in Franklin Township, New Jersey. The building that housed Kiddie Kollege was formerly a thermometer factory that used mercury and that subsequently was sold, renovated, and certified for use as a daycare center. Concerns surfaced about the past use of the building and potential impact of that use on the health of the children and staff. CDC’s Environmental Health Laboratory analyzed urine samples from Kiddie Kollege staff and students for possible mercury exposure. Previous nationally representative data on human mercury urinary levels published in CDC’s Third National Report on Human Exposure to Environmental Chemicals were used as reference levels to which levels in the children and staff were compared.
Understanding the employees’ and parents’ concern about the need for further testing, CDC and ATSDR provided additional assistance to the New Jersey Department of Health and Senior Services (NJDHSS) for several rounds of follow-up testing. As a further measure, the NJDHSS and ATSDR reviewed the medical records of any child or adult who attended or worked at the daycare center to assess whether an individual’s past or present medical conditions were consistent with mercury poisoning. After each review, if further medical follow-up was indicated, the child’s parents and physician were referred to the Pediatric Environmental Health Specialty Unit at the Mt. Sinai School of Medicine in New York or to the Robert Wood Johnson School of Medicine in New Jersey for additional testing or evaluation.
Most children had levels of mercury in their urine that were not unusual and that were consistent with national reference values. Some children had urine levels of mercury that were slightly higher than national reference values, and these children underwent several subsequent rounds of testing. The low urine levels of mercury in these children and the slight decline of the levels over time were consistent with background sources (i.e., diet or dental fillings) and a contribution from the daycare center exposure. No urine levels of mercury were in a range known to be toxic. Our laboratory tested a total of 189 urine samples during this investigation.
In May 2004, health officials reported an outbreak of jaundice in two districts in Kenya with a high case-fatality rate. This outbreak was caused by widespread contamination with aflatoxin of locally grown maize. Aflatoxin is the name given to any group of toxic compounds produced by certain molds. In this case, fungus had grown on the grain and produced a toxin. The Environmental Health Laboratory played a major role in the success of this investigation through its use of sophisticated laboratory techniques to provide the best possible evidence that people in the two affected areas had been exposed to aflatoxin. These techniques, which had never before been used in an outbreak, directly measured toxins in blood samples from people who had eaten the maize. As a result, officials had a much more accurate assessment of exposure than would have been possible by estimating exposure on the basis of measuring toxins in food samples. These efforts not only helped stem the outbreak in Kenya, but will also be key to developing strategies for preventing future tragedies caused by people’s exposure to aflatoxin.