17 October 2006

Additives or Not: The Anthrax Mailed in October 2001 Could Form an Aerosol and Could Reaerosolize.

Five years ago this month two letters containing anthrax spores were mailed to Senators Tom Daschle and Patrick Leahy. The letters were postmarked October 9, 2001 in New Jersey. Both letters then traveled through the large postal facility in Washington DC, known at the time as Brentwood. The letter to Senator Daschle was opened on October 15, 2001 and therefore, understandably, five years later to the day, an article he writes in the Washington Post begins: “October 15, 2001 is a day I’ll never forget” (Washington Post. Page B07. Oct 15, 2006).

The FBI has also not forgotten. Two months ago they published a description of the forensic evaluation of the unopened letter to Senator Leahy, titled: ”Forensic Application of Microbiological Culture Analysis to identify Mail Intentionally Contaminated with Bacillus anthracis spores. Applied and Environmental Microbiology (2006 (August); 72 (8):5304-5310 . The single author of this paper is Douglas J. Beecher, from the FBI Laboratory in Quantico, Virginia.

Even more recently, on September 25, 2006 the Washington Post published an article on page A01 titled “FBI is Casting a Wider Net in Anthrax Attacks”, authored by Allan Lengel and Joby Warrick. This article begins, “Five years after the anthrax attacks that killed five people, the FBI is now convinced that the lethal powder sent to the Senate was far less sophisticated than originally believed, widening the pool of possible suspects in a frustratingly slow investigation. The finding, which resulted from countless scientific tests at numerous laboratories, appears to undermine the widely held belief that the attack was carried out by a government scientist or someone with access to a U.S. biodefense lab.”

Although “The FBI would not allow Beecher to be interviewed about his article”, the Washington Post writers quote from his August 2006 paper in Applied and Environmental Microbiology: “A widely circulated misconception is that spores were produced using additives and sophisticated engineering supposedly akin to military weapons productions”. In their September 25 Post article, Lengel and Warrick also quote from a former Soviet bioweapons scientist Sergei Popov, now working at George Mason University, regarding the Ames strain of anthrax found in the 2001 anthrax letters: “Ames was available in the Soviet Union…It could have come from anywhere in the world”.

The August 2006 by Beecher provides great detail on the forensic examination of the letter to Senator Leahy, including the effect of personal protective equipment (PPE) contamination while personnel were investigating the Leahy letter (Table 1, page 5307), and the anthrax contamination studies of 20 letters also postmarked October 9, 2001 in Trenton, New Jersey close in time to the “Daschle and Leahy letters” (Table 2). Of note, however, no new data is provided in the “Results” section of the paper regarding the presence or absence of any additives to the anthrax spores in the letter.

In the “Discussion” section of the paper (page 5309) however, Mr. Beecher states that ”Individuals familiar with the composition of the powders in the letters have indicated that they were comprised simply of spores purified to different extents (6)”. This single reference # 6 is from an article titled “Anthrax powder: State of the Art?” published 28 November 2003 in Science (volume 302, pages 1492-1497) by Gary Matsumoto, described at the end of the five-page article as an investigative journalist.

For this 2003 article, Matsumoto interviews many persons and discusses a spectrum of possibilities ranging from no additives being found (see page 1494 that refers to FBI scientists) to discussion of whether certain additives were present. Mention of polymerized glass, silica, and use of nanotechnology are made, for example, but no definitive data presented that any additives were found. At least one expert is cited as suggesting that the anthrax spores in the letter “could have acquired a charge from friction as the envelopes passed through mail-sorting machines” (p. 1493). These electrical charges could have helped create a “self-dispersing powder” that increased the chance of allowing the spores to reach the deepest parts of the lungs where they would cause inhalational anthrax.

A common theme from the 2006 paper by Beecher, and the 2003 article by Matsumoto is the aerosol nature of the anthrax spores in the letters postmarked October 9, 2001. This theme is supported by their publications and a December, 2002 Journal of the American Medical Association (JAMA) paper by the US Environmental Protection Agency and other government organizations involved in a study of the Hart Senate Office Building after it was closed following the anthrax attack:

1. Douglas Beecher (FBI). Applied and Environmental Microbiology 2006 (August) 72 (8): 5304-531: “…physically handling the intentionally contaminated letter proved to be exceptionally hazardous, as did sorting of cross-contaminated mail which resulted in generation of hazardous aerosol and extensive contamination of protective clothing” (page 5304).

2. Gary Matsumoto. Science 2003 (Nov 28); 302: 1492-97. “There is no debating that the Senate powder was exceptionally pure and highly concentrated…But what made it truly remarkable, according to biodefense specialists, was its conversion into a cutting-edge aerosol” (page 1493)

3. Weis et al. Secondary Aerosolization of viable Bacillus anthracis spores in a contaminated US Senate Office. J Am Med Assn (JAMA) 2002 (Dec 11)288: 2853-58. “Viable B. Anthracis spores reaerosolized under semiquiescent conditions, with a marked increase in reaerosolization during simulated active office conditions…these findings have important implications for appropriate respiratory protection, remediation, and reoccupancy of contaminated office environments” (page 2853).

Some, but not all, studies at the Dugway Providing Ground in Utah similarly documented decades ago the ability of Bacillus subtilis, an anthrax simulant, to reaerosolize (Resnick IG et al. Evaluation of Need for Detection of Surface Biological Agent Contamination: Dugway Proving Ground, Life Sciences Division, US Dept of the Army; 1990; 1-35. Publication DPG-FR-90-711. (also cited by Inglesby et al. JAMA (May 1) 2002; 287: 2236-52. See reference 107).

Future biodefense planning for anthrax attacks, especially if aerosolized attacks as envisioned in the US Cities Readiness Initiative (CRI), should emphasize the ability of the anthrax spores to form a biohazardous aerosol, and to reaerosolize as documented in the Hart Senate Office Building.

Daniel R. Lucey, MD, MPH

Director, Center for Biologic Counterterrorism and Emerging Diseases

EROne Institutes, Department of Emergency Medicine, Washington Hospital Center

Co-Director, Master of Science Program in

Biohazardous Threat Agents and Emerging Infectious Diseases

Georgetown University Medical Center, Washington, DC

Website posting: www.BePast.org e-mail: Daniel.R.Lucey@Medstar.net