There wasn't much information about the lead contamination at the 11th and Monroe Park when I first heard about it, and now there's a bit more. WUSA and TBD both have articles: apparently there was some demolition at 3511 13th Street NW and clouds of dust, including lead, fell down into the park. It sounds pretty bad -- from the WUSA article: "It was like a snowstorm of dust," says Michael Northern. "The individual I was sitting down playing dominos with, he started turning white right before my eyes, that's how much dust there was."
The District's Department of the Environment said about 40 people have been tested but results aren't back yet. They're encouraging people with kids and the elderly to get tested. They have a testing truck on Monroe just west of 11th which will be there every day from 8 am to 8 pm, and there's also a testing center at the Columbia Heights Community Center at 1480 Girard St. NW.