Lead

CAS ID#: 7439-92-1

Affected Organ Systems: Neurological (Nervous System), Renal (Urinary System or Kidneys)

Cancer Classification:  Please contact NTP, IARC, or EPA with questions on cancer and cancer classification.

Chemical Classification: Inorganic substances

Summary: Lead is a naturally occurring bluish-gray metal found in small amounts in the earth's crust. Lead can be found in all parts of our environment. Much of it comes from human activities including burning fossil fuels, mining, and manufacturing. Lead has many different uses. It is used in the production of batteries, ammunition, metal products (solder and pipes), and devices to shield X-rays. Because of health concerns, lead from gasoline, paints and ceramic products, caulking, and pipe solder has been dramatically reduced in recent years.

CDC uses a blood lead reference value (BLRV) of 3.5 micrograms per deciliter (µg/dL) to identify children with higher levels of lead in their blood compared to most children. This level is based on the 97.5th percentile of the blood lead values among U.S. children ages 1–5 years from the 2015–2016 and 2017–2018 National Health and Nutrition Examination Survey cycles. Children with blood lead levels at or above the BLRV represent those at the top 2.5% with the highest blood lead levels. To learn more about CDC’s updated recommendations on children’s blood lead levels, please visit: http://www.cdc.gov/nceh/lead/ACCLPP/blood_lead_levels.htm.