Older houses may still be painted with lead-based paint. Apparently this paint tastes good to some young children, who have been known to peel off flaking paint and eat it. If you want to protect your children from the temptation to eat paint, or if you're just tired of looking at flaking paint, warped wood, and moldy drywall, you want to replace the lead-painted surfaces, right? And if you want to get the job done fast, maybe during a weekend while the kids are at Grandma's house, you hire professional help...and then you run into trouble.
Contractor John DiPrimio sounds off in the Philadelphia Inquirer (Warning: this site is supported by advertisers who may generate annoying pop-ups, and if you log in to comment and tell DiPrimio you appreciate his comments, you'll have to agree to receive spam).
Since I don't need spam and don't actually shop in Philadelphia (at least not often), I can't comment there, so I'm commenting here. Dittos!