The Swirl Of 5,209 public spas (hot tubs, whirlpools, Jacuzzis and the like) inspected in 2002, more than half were cited for potentially health-impairing maintenance violations, according to a report by the Centers for Disease Control and Prevention (CDC). Eleven percent had problems so severe they were shut down. Home spas weren't inspected, but "we suspect that . . . the same type of situation exists" in homes, said Michael Beach, an epidemiologist with the CDC's Division of Parasitic Diseases.

The Dirt Skin rashes and respiratory ailments, the most common health problems linked to spas, are caused by water-borne bacteria. Spa water's warm temperature encourages bacteria growth. When the water isn't properly disinfected and pH-balanced, bacteria grow unchecked; the slimy film that accumulates on tub walls shields bacteria from disinfectant. "It's not the number of bodies using the tub that contributes" most to the problem, Beach said, "but the environment."

The Fix Beach says home-spa owners -- like public-spa operators -- should disinfect tub water at least weekly with a biocidal shock (an oxidizing chemical that destroys organic contaminants), maintain proper pH levels (7.2 to 7.8, states the report) and scrub away that slimy film.

Disinfectant systems employing ultraviolet light or ozone can be useful supplements to -- but not replacements for -- chemical disinfectant regimens, Beach said. Systems that automatically test and treat water are fine, he added, but owners should periodically test the water to make sure the system is working properly.

Getting Personal Beach reminds spa users that "it's not a bathtub. You need to bathe or shower beforehand." And afterward, too.

-- Jennifer Huget