What is lead?
Lead is a naturally occurring metal found deep within the ground. It occurs in small amounts in ore, along with other elements such as silver, zinc or copper. Even though it's found in small amounts, there is an abundant supply of lead throughout the earth. Because it is widespread, easy to extract and easy to work with, lead has been used in a wide variety of products including:
Since 1980, federal and state regulatory standards have helped to minimize or eliminate the amount of lead in consumer products and occupational settings.
Today, however, the most common sources of lead exposure in the United States are:
- Lead-based paint in older homes
- Contaminated soil
- Household dust
- Drinking water
- Lead crystal
- Lead-glazed pottery
How much lead is harmful?
No amount of lead is safe. Eliminating all lead exposure in our environment is our best course of action.
New findings from NIEHS-supported grantees, as well as the National Toxicology Program (NTP) have found many adverse health effects in both children and adults at blood lead levels below 10 micrograms per deciliter (μg/dL) and for some below 5 μg/dL.
These findings add to the body of evidence that have led the Centers for Disease Control and Prevention (CDC) in 2012 to now advise that any child with more than 5 micrograms per deciliter of lead in their blood to be considered at risk and that public health actions should be initiated.
What are some of the health effects associated with lead exposure?
The 2012 NTP literature-based monograph on health effects of low-level lead provides this information on health effects:
|Blood Lead Level||Health Effects|
|Blood lead levels below 5µg/dL|
Decreased academic achievement, decreased IQ, and decreases in specific cognitive measures, increased incidence of attention-related behaviors and problem behaviors
Decreased kidney function, maternal blood lead associated with reduced fetal growth
|Blood lead levels below 10µg/dL|
Delayed puberty, reduced postnatal growth, decreased IQ and decreased hearing
Increased blood pressure, increased risk of hypertension, and increased incidence of essential tremor
Chronic lead exposure in adults can result in:
- Increased blood pressure
- Decreased fertility
- Nerve disorders
- Muscle and joint pain
- Memory or concentration problems
Who is at the greatest risk for exposure?
Children under the age of 6 years old are at an increased risk for lead exposure, due to their rapid rate of growth and their tendency to place toys and other objects in their mouths that could contain lead or leaded dust. This is particularly true of children living below the poverty line in older housing.
What can I do to prevent lead exposure?
- Assess the construction year of your home and or daycare facility. If construction occurred prior to 1978, assume lead-based paint was used unless testing shows otherwise.
- Contact your local or state health department for information about paint and dust testing in your home.
- Take precautions to keep children away from peeling and or chewable surfaces which may contain lead-based paint. Barriers may include:
- Closed doors
- Baby gates
- Contact paper
- Duct tape
- Wash children’s hands and toys regularly.
- Wet-mop floors and wet-wipe windows regularly to eliminate potentially leaded dust.
What NIEHS is Doing on Lead
The Treatment of Lead-Exposed Children Trial (TLC)
The TLC was a four-city clinical trial to assess the effectiveness of succimer, an oral drug therapy, as a preventative for lead-induced disorders of growth, behavior, and cognitive development in toddlers. Jointly funded by NIEHS and the National Center for Research on Minority Health and Health Disparities, the study examined 780 children between 13-33 months of age (all with heightened blood lead levels), and inevitably determined that the drug had little, if any benefit.
- For additional information on the TLC and its findings, visit the TLC webpage.
Other NIEHS and NTP resources include:
- NTP Monograph: Health Effects of Low-Level Lead
- NTP Profile: Report on Carcinogens: Lead (12th ROC)
- Child Development and Environmental Toxins
Fact Sheets and Brochures:
- CDC: What Do Parents Need to Know to Protect Their Children? - Information on the CDC’s 2012 recommendations on children’s blood lead levels.
- HHS Household Products Database: Lead (Profile)
- HHS Household Products Database: Lead Compounds (Profile)
- Lead and Environmental Health - A compilation of links to websites on lead that provide an overview of the problem, glossaries and dictionaries, data and research, and literatures sources. Spanish language materials are also available.
- Reducing lead contamination in urban soils (http://www.niehs.nih.gov/news/newsletter/2013/10/science-lead/index.htm)
Where can I go to learn more?
- U.S. Environmental Protection Agency
- Occupational Safety and Health Administration
- World Health Organization
- Centers for Disease Control and Prevention
- Agency for Toxic Substances and Disease Registry
- U.S. Department of Housing and Urban Development
- CDC: National Lead Poisoning Prevention Week Toolkit - A compilation of resources including downloadable posters and flyers, web banners, widgets, and an assortment of other news and event information.
- Childhood Lead Poisoning Prevention - This webpage (part of the “Family Health A-Z” series) is a service of the New Jersey Department of Health.