What is Lead Poisoning?

Smiling children sitting outside

What is Lead?

Lead is a naturally occurring element found in small amounts in the earth's crust. Lead was mined in Wisconsin. It was used in many products to stabilize things such as paint, varnish, gasoline, plastics, etc. However, lead is toxic to humans and animals. Using lead in products to which children and adults have ready access can cause lead poisoning.

What is Lead Poisoning?

Lead poisoning is an environmental disease that can cause brain damage. It can result in reduced IQ and attention span, learning disabilities, developmental delays, and a range of other health and behavioral effects. Lead poisoning is considered a housing-based disease because most exposures for young children occur in homes or child care centers built before 1978. In 1978, lead was banned from being added to paint and varnish for residential use. However because lead was added to paint, varnish and gasoline for many years, the lead is still present in the underlying layers of paint and varnish and in the soil.

How Does Lead Poison?

  • Chipping and peeling lead-based paint in older homes is ground to a very fine dust and is largely invisible. The lead dust may be in windows, on floors and porches and in the soil. When the lead-tainted dust gets on children’s hands and into their mouths they can become lead poisoned.
  • Another common way people get exposed to lead is when lead-based paint is being disturbed during renovation or remodeling. If the person doing the renovation is not working safely with the lead-based paint, the lead fumes and dust in the air can be inhaled or can be ingested by anyone in the area.
  • Other sources of lead exposure can include lead in drinking water service lines and fixtures; lead in soil from leaded gasoline, paint and industrial emissions; and lead in products such as toys, children's jewelry, candies, and traditional remedies, among others. 

How Can We Prevent Lead Poisoning?

Prevention of lead poisoning can be accomplished by eliminating lead hazards before children are exposed. Wisconsin's goal is to eliminate this disease by making Wisconsin's housing lead-safe, and by intervening early to stop the lead exposure before it can cause further harm to children.

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Lower Level Intervention

Previously, a child's blood lead level BLL ≥10 micrograms per deciliter (mcg/dL) was considered in need of intervention. In May 2012, the Centers for Disease Control and Prevention (CDC) concurred with its advisory committee's recommendation to lower that level to 5 mcg/dL. The recommendation was made due to overwhelming evidence that lead exposure at levels below 10 mcg/dL causes damage to the cognitive, cardiovascular, endocrine, and immune systems.

The advisory committee also recommended that CDC change its guidelines so that interventions previously identified for a BLL of 10 mcg/dL or greater go into effect at the new intervention level of 5 mcg/dL. CDC recommends the following interventions for a child with a BLL of 5 mcg/dL or greater:

  • Confirm a capillary blood lead test with a venous draw within 1 to 3 months.
  • Have child tested on the appropriate follow-up testing schedule.
  • Get a complete history and physical exam on the child.
  • Order the appropriate laboratory tests on the child such as tests for low iron or anemia.
  • Monitor the child's growth and development, especially as the child ages and enters school.
  • Provide education to the family on the sources of lead and how to reduce any lead hazards found.

This change significantly increased the number of Wisconsin children considered at risk for lead poisoning. More children being identified as having lead exposure earlier means that parents, doctors, public health officials, and communities can take action earlier. The advisory committee also said, as CDC has long said, that the best way to protect children is to prevent exposure in the first place. More information can be found in the advisory committee's report to CDC (PDF, 922 KB).

Additional Resources

Report on Childhood Lead Poisoning in Wisconsin - 2014 (P-01202, PDF, 1.5 MB)

Parents: Look Out for Lead (P-00660, PDF, 8 MB)

Your Child's Blood Lead Test Results (PDF, 861 KB) - National Center for Healthy Homes fact sheet and checklist for parents ¦ En Español (PDF, 169 KB)

Blood Lead Levels in Children (PDF, 292 KB) - Centers for Disease Control and Prevention fact sheet with guidance for health care providers when talking with parents about their child's blood lead level

Reliable Sources for More Information

U.S. Centers for Disease Control and Prevention - English ¦ En Español

U.S. Environmental Protection Agency - English ¦ En Español

U.S. Housing and Urban Development - English

Last Revised: February 10, 2017