what is the average lead level for a 4 year old?

Answer 1

The average 4 year old (and older children) has a lead level less than 10 micrograms per decileter (0.48 micromols/Liters).

This is also the current cutoff for what is considered potentially toxic, though this has gradually decreased through the years in the U.S. Prior to 1971, 60 micrograms/dL was the lower cutoff, then 40 in the 70s, then 25 in the 80s. Since 1991, 10 has been the cutoff...and it hasn't changed in the past 15 years.

Hope this helps.