Soil is indeed the major source of lead in the US, along with water. Consumer goods lag far, far, far behind.
Lead can also be purged out of body with a diet rich in calcium, iron, and vitamin C. (which is good for you for other reason too!)
The EPA has a handy PDF on the subject, including high iron, high calcium, high vitamin C meals and snacks you can feed to the kids:
http://www.epa.gov/lead/pubs/nutrition.pdf(side note, but many of the recipes are designed so they can be made with items available through WIC)
They have another PDF on how to clean your house to minimize lead dust from paint or tracked in as dirt:
http://www.epa.gov/lead/pubs/leadpdfe.pdfThey mention spinach in the article as being a good way to draw lead out of soil. IRONY: Marijuana is also an excellent way to draw lead and other heavy metals out of soil. It's been used at Chernobyl to take radioactive material out of the soil and water:
http://www.mhhe.com/biosci/pae/botany/botany_map/articles/article_10.html