Venipuncture is the method of choice for blood lead testing as it is less subject to contamination from the skin surface than capillary collection.
Lead Determination - Guidelines for Capillary Blood Collection
0-5 years:0-4 ug/dL*6-17 years: 0-10 ug/dLAdults (>17 years): 0-25 ug/dL
*CDC 2012 guideline; Nov 2012. CDC MMWR, 62(13); 245 - 248, April 15, 2013.Based on the 97.5th percentile of the NHANES's blood lead distribution in children.