Here’s an article from Mayo Clinic:
Lead Poisoning
By Mayo Clinic staff
Lead poisoning occurs when lead builds up in the body, often over a period of months or years. Even small amounts of lead can cause serious health problems. Children under the age of 6 are especially vulnerable to lead poisoning, which can severely affect mental and physical development. At very high levels, lead poisoning can be fatal.
Lead-based paint and lead-contaminated dust in older buildings are the most common sources of lead poisoning in children. Other sources of lead poisoning include contaminated air, water, soil, and some toys and cosmetics.
Much More:
http://www.mayoclinic.com/health/lead-poisoning/fl00068
That sounds very familiar to the Wikipedia entry, they are not a great source but they do correct entries for lies and falsehoods.
Basically Wiki is for lightweights which is why I chose it for the guy who doesn’t believe in lead poisoining. First link in a very easy search.
Google or izquick it and there’s a ton of easy links.