The Water Cooler Dilemma

Late last summer, six researchers at Harvard University's medical school fell into a poisoner's trap. Each poured a cup of coffee from a communal coffee maker in the school's pathology department. All of them ended up in the hospital; some had fainted, others were dizzy and nauseated, most couldn't hear over the ringing in their ears.

Investigators quickly discovered that the coffee machine's water tank had been laced with laboratory preservative called sodium azide, used to keep bacteria from growing in chemical solutions.  This offered up an almost limitless pool of suspects - anyone working in a research lab would have access to the compound and would also know that it was classed as an exceptionally dangerous material.

Sodium azide is made of one sodium atom linked to three nitrogen atoms, giving it the chemical formula of NaN₃. It directly interferes with the enzymes that work to move oxygen in the blood stream, causing a kind of chemical suffocation. The lack of oxygen causes immediate dizziness. It's also a powerful vasodilator, meaning that it rapidly relaxes blood vessels, precipitating a free-fall in blood pressure. Hence the fainting. But my favorite gruesome fact about sodium azide is that it can react with stomach acids to form a new material (hydrozoic acid) which happens to be explosive. Imagine that scene in a hospital emergency room.

All of the scientists poisoned at Harvard last summer survived and recovered fully. But no suspect was ever charged. And today, the Harvard Crimson reported (see link below) that the university's police department was no longer actively working on the case, after interviewing 150 people and getting no closer to an answer.

Which brings me to what I always think of as the water cooler dilemma in toxicology.  These kinds of poisonings - sneaking a risky compound into a shared food or drink supply - are incredibly hard to solve. The victims appear so random that a personal motive is difficult to establish. If investigators can't find someone with a widely held grudge, if the poisoner hasn't made a mistake (caught on camera dumping sodium azide into a water tank), if no one confesses, then police can only hope to catch some lucky break.

One case that I explored in my book involved a poisoner who secretly mixed arsenic into the pastry bowl at a restaurant in New York City.  Sixty people were sickened after eating lunch and six of them died. That happened in 1922 and to this day, no one knows who added the arsenic into the mix.  On the other hand, there are exceptions. When my father was a chemistry student at Northwestern University - that would be back in the late 1940s - the janitor in his laboratory mixed sodium cyanide into the canister of tea leaves the students kept at hand. And that man was caught and, according to my parental source, was demonstrably crazy.

So maybe they'll get lucky at Harvard. The police are still soliciting tips. In the meantime, the medical school has added surveillance cameras, placed new protective devices on its water filters, and - oh, yes - removed the coffee makers from the pathology laboratory. Just another reminder that poisoners do not make the world a better place.

http://www.thecrimson.com/article/2010/1/27/medical-hupd-school-laborat…