Canada's "Toxic Bus": The New Challenge for Law Enforcement in the Post-9/11 World/Mass Psychogenic Illness

Talk of the devil, and he is bound to appear.

—Proverb

Episodes of mass psychogenic illness are challenging under the best of circumstances. Typically incubated in an atmosphere of fear and uncertainty, the initial diagnoses are often contentious, and it takes time for environmental tests to be processed. Even when results come back negative and a psychogenic cause is the obvious assessment, there is often a backlash from victims and community members, who resent the "mass hysteria" label, which is typically viewed as something that happens to others. For this reason, cases are often officially left unresolved under the guise of "mystery illnesses" or possible terrorist attacks, as occurred in the following Canadian case, which documents the caveats faced by law enforcement and emergency medical personnel, resulting in an inefficient use of time and resources, and unnecessary public anxiety.

The Episode

On Tuesday 25 May 2004, at approximately 1 p.m., a passenger walked to the front of public TransLink bus #98 in downtown Vancouver, British Columbia. As "the Richmond Express" came to a halt at the intersection of 49th Street and Granville Avenue, the disembarking man made a cryptic remark. As one passenger recalled, "He said how's your day going . . . and the bus driver said good. Then the man said it won't be for long" ("Passenger" 2004).

As the driver continued his route, he began to feel nauseated, and later vomited after travelling 10 kilometres from where the man had stepped off. He then asked if any passengers felt ill. When one replied affirmatively, he steered the bus to the roadside and radioed for medics, fearing a chemical or biological attack. As the two responding paramedics began to treat the driver and hear his version of events, they too fell ill. Others arriving on the scene also felt sick. The incident made headlines around the world as a possible terrorist attack and became the focus of a major investigation that would become known as "the toxic bus case," or police file #04-128479.

Immediately after the incident, 19 people, including the driver, passengers, emergency personnel, and journalists, were briefly quarantined. Air quality tests and a forensic examination of the bus were unremarkable. Vancouver Police searched for the suspect: an olive-skinned male in his mid-20s, with an average build, pencil-thin moustache, and a "5 o'clock shadow." This description, suggesting that he may have been Middle Eastern, likely heightened suspicion and fear of terrorism (Vancouver Police Department 26 May 2004, 28 May 2004).

In early June, the incident became the subject of a public dispute between Vancouver's Chief Medical Health Officer, John Blatherwick, who maintained that the cause was "mass anxiety," and both police and ambulance agencies, who disagreed. At a police press conference, a spokeswoman rejected Blatherwick's position, noting that "he is not involved in the investigation and he is misinformed. The investigation remains active, as toxicology results are still not complete" (Vancouver Police Department 11 June 2004).

On June 25, Vancouver Police made a startling announcement: When tests of the bus by the Royal Canadian Mounted Police were unrevealing, they hired a private firm to conduct further tests, which identified methyl chloride as the chemical in the "attack." Reporters were told that "in high concentrations [methyl chloride] is capable of killing someone. While it is impossible to say how much of the gas the victims were exposed to or how it came to be delivered into the air on the bus, it would have taken a fairly high concentration to force the gas into some of the materials on the bus, such as seat fabric and the air filters" (Vancouver Police Department 25 June 2004).

One of the lead police investigators publicly defended his department's interpretation of the methyl chloride findings, but on emotional, not scientific grounds, implying that elite medical professionals are immune from mass hysteria: "You're talking about two very senior ambulance attendants and they're not going to have psychosomatic symptoms, they've seen everything" (Crawford...