The myth of the mists

When the systems are shut off at night, the residual water left in the pipes becomes stagnant and, at summer temperatures, becomes the perfect breeding ground for little nasties.

by Dr. Matthew C. Marturano — 

In the legends of King Arthur, it was said that only the most adept of the priestesses could raise the Mists of Avalon, which revealed the path to the ancient island, fabled to have existed near the town of Glastonbury, England.

Many here in the Valley still seek out the mists, hoping to gain a brief respite from the scorching summer sun while enjoying their dinner on the patio of a local neighborhood restaurant. Misters can provide a bit of relief from the heat and a touch of ambiance, but they may also pose serious health risks to unwitting patrons.

The two diseases in question are caused by Legionella, a group of bacteria found naturally in freshwater environments.

The first variant, known as Legionnaires’ disease, affects only five percent of people exposed to the bacteria, but can rapidly progress into a severe form of pneumonia with a fatality rate of 15 percent in normal people, and up to 80 percent in the elderly or immunocompromised. A milder form of disease, known as Pontiac fever, does not cause pneumonia, but can present in up to 95 percent of exposed persons.

Infection is caused by inhalation of aerosolized water droplets from a number of building systems, including cooling towers, evaporative condensers, domestic hot water systems, spas, whirlpools, humidifiers, decorative fountains, faucets, showerheads and, yes, those much adored misting systems.

Control of these unfriendly bacteria is achieved by one of two methods: the first is superheating the water source to at least 158°F (70°C) for 24 hours; the second is chlorine shock treatment.

Most of these systems come with built-in mechanisms to control the spread of diseases; however, the biggest risk is posed by misters. The primary problem is that they do not run continuously. When the systems are shut off at night, the residual water left in the pipes becomes stagnant and, at summer temperatures, becomes the perfect breeding ground for little nasties. The next day, when they are restarted, millions of freshly spawned bacteria are spewed into the air, ready to wreak havoc on unsuspecting patrons who simply want to enjoy their dinner and a view.

Certainly, a conscientious restaurateur will maintain the chlorine treatment necessary to control the growth of these bugs, but it is impossible to tell for certain, without asking, whether anyone is maintaining the misters.

Not to mention that the regularly treated misters shower your food with a continuous spray of chlorine. Mmmm … appetizing, is it not?

Perhaps we would do better to leave the mists to the priestesses who best knew how to handle them.

Dr. Matthew C. Marturano is a naturopathic physician and owner of Sun Valley Integrative Medicine in Tempe, Ariz. His practice focuses on the prevention and treatment of diabetes, arthritis, anxiety and depression. 480-797-4981.

Reprinted from AzNetNews, Volume 24, Number 4, August/September 2005.