摘要：Objectives. In October 2003, a package containing ricin and a note threatening to poison water supplies was discovered in a South Carolina postal facility, becoming the first potential chemical terrorism event involving ricin in the United States. We examined the comprehensive public health investigation that followed and discuss the lessons learned from it. Methods. An investigation consisting primarily of environmental sampling for ricin contamination, performance of health assessments on affected personnel, and local, regional, and national surveillance for ricin-associated illness. Results. Laboratory analysis of 75 environmental sampling specimens revealed no ricin contamination. Health assessments of 36 affected employees were completed. Local surveillance initially identified 3 suspected cases, and national surveillance identified 399 outliers during the 2-week period after the incident. No confirmed cases of ricin-associated illness were identified. Conclusions. A multifaceted and multidisciplinary approach is required for an effective public health response to a chemical threat such as ricin. The results of all of the described activities were used to determine that the facility was safe to reopen and that no public health threat existed. On October 15, 2003, a small, closed, metal canister within a package was found in a postal processing facility in Greenville, SC, with a note threatening to poison water supplies if certain demands were not met. 1 That same day, the facility manager made a call to the Inspection Service Office in Greenville, which advised him to call emergency responders. Approximately 1 hour later, emergency responders, members of local law enforcement and the local fire department’s hazardous materials unit, arrived at the facility, and the building was evacuated. The package was isolated from postal workers and Federal Bureau of Investigation Joint Terrorism Task Force representatives coordinated transport of the package. The South Carolina Department of Health and Environmental Control (SC DHEC) received the package at approximately 10:00 am on October 16, 2003. Using a standard “all agents” testing approach, the South Carolina Bureau of Laboratories tested for several agents, including anthrax, but did not have the capability at that time to test for ricin. The Centers for Disease Control and Prevention (CDC) was contacted, and handling and testing of suspicious substances was discussed. Because the substance was in a well-sealed metal container, the South Carolina Bureau of Laboratories and CDC decided that the risk of exposure was low. The CDC requested that South Carolina Bureau of Laboratories officials send the specimen via an overnight express courier on October 20, 2003, for analysis. Samples were shipped to the CDC and were confirmed to be ricin on October 21, 2003. 1 A team of professionals with expertise in medical toxicology, industrial hygiene, and epidemiology traveled to the site from the CDC that same day, and the facility was closed for a detailed epidemiological and environmental sampling investigation. 1 The CDC and SC DHEC conducted a case finding for potential ricin-associated illness among postal workers at the facility where the ricin was discovered and initiated state, regional, and national surveillance for potential ricin-associated illness. 1 Ricin is a deadly protein toxin, or toxalbumin, derived from the castor bean plant, Ricinus communis . 1 – 3 The clinical effects that may result from ricin exposures are primarily because of nonspecific inhibition of protein synthesis resulting in nonspecific cellular dysfunction and death. 1 – 3 Ricin has been used as a poison in both criminal and terrorist events. 4 – 7 A substantial lack of knowledge exists in established procedures for responding to potential environmental contamination of many poisons, including ricin. Health assessments of affected individuals and surveillance activities are also needed to assist in the evaluation of a public health threat. The anthrax exposure events of 2001 revealed a fundamental lack of knowledge in the medical and public health communities regarding the relationships among contamination, human exposure, and disease. 8 Environmental sampling is critical to identify and characterize the extent of contamination. 8 , 9 Qualitative and quantitative assessment of the extent of contamination is necessary to control the hazard, determine human exposure, and implement appropriate interventions to avoid adverse health effects. 8 , 9 However, the relationship between environmental contamination of ricin and subsequent health risk from exposure is unclear. Thresholds have not been established for many agents, including ricin, and often no guidelines exist for result interpretation. To our knowledge, this study is the first explicitly detailed description of a public health and environmental sampling investigation for a possible chemical terrorism event involving ricin. Our primary objective was to describe in detail the various components of the public health investigation to assist in future responses to ricin-associated public health threats. Our secondary objective was to describe the public health consequences resulting from the lessons learned in this incident.
