Nasty D.C. ‘biofilm’

In a small break from the usual headlines, this story last week from The Washington Post was too interesting not to share: Seems there’s a weird and gross grunge growing on the stones of some of the capital’s most treasured monuments — worst of all, at the Jefferson Memorial.

Says the Post: “It’s biofilm — a microbial invasion of uncertain origin that has begrimed the stone surface of one of the nation’s most hallowed monuments. Part algae, part bacteria, part fungi, the biofilm won’t eat your flesh, like the gooey Blob in the 1958 horror film, as a National Park Service spokesman remarked. But it’s not clear if it’s munching on the stone. And it can’t be killed. It has given the elegant white memorial on Washington’s Tidal Basin a dingy look and it is growing.”

The National Park Service is testing cleansing methods as the biofilm has crept onto other D.C. sites, including the Lincoln Memorial. Ick!

Send your cleaning ideas for sun-bleached marble to