Zoanthid corals are a favorite with aquarium hobbyists — beautiful and easy to grow (easy being a relative term — coral's always a pain in the ass).

Most people who keep coral know that they have to be careful when handling it they can poison you on contact with palytoxin, which bonds to sodium-potassium ATPase and disrupts the potassium/sodium balance in cells, killing them (and in sufficient doses, killing the organism too). What wasn't well-known (until a rash of emergency room visits in Anchorage) is that fragments of coral that are left exposed to air release an invisible, highly toxic aersolized gas that can seriously poison everyone in your home.

The man who showed up in the ER on August 12 had not worked with or handled a zoanthid coral. But one of his relatives had. Just 7-8 hours earlier, this relative had transferred 70 pounds of live zoanthid coral from a plastic container into the patient's 200 gallon aquarium inside his 1,600-square-foot mobile home. While this was being done, some pieces of the coral fell on the floor, and some live polyps broke off. Two people were sleeping in a room next door. The man who later showed up in the ER got home later and slept for seven hours in the same room as the aquarium. All through the night — and let me emphasize that you just can't make this stuff up — the coral seems to have exuded some sort of creeping death mist. According to the CDC's venerable Morbidity and Mortality Weekly, "Patients A and C noted a visible mist and sensed humidity in the mobile home on the morning after coral introduction, leading them to suspect a possible problem with the aquarium." The next morning, all three people awoke with a nasty suite of neurologic, breathing, and muscle problems. The man who'd slept in the room with the aquarium was worst off. His fever had reached 103°F and his white blood cell count was elevated. He spent two days in the hospital before recovering.

Aquarium Corals of Anchorage Poison 10 1/2 Humans, 2 Dogs and 1 Cat

[Jennifer Frazer/Scientific American]

(Image: A colony of "dragon eye" coral, Kazvorpal, CC-BY-SA)