I spoke to my painting contractor who just took EPA's lead safety class, and I would advise Homeowners to test your windows for lead paint if your home was built in 1978 and prior. If you detect lead during testing, I would advise to replace your windows and sill's, because they are one of the biggest causes of lead poisoning. By opening the window's, lead dust is created and the room becomes contaminated. This is the major concern, because it effects small kids and pregnant women if they live in the house.
I wrote in the past that EPA's Lead Poisoning rule went into effect in 22 of April. Any contractor who is doing work on the home built in 1978 or prior, must have EPA's lead certification.