Lead | NIEHS

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:

• Paint
• Ceramics
• Pipes
• Solders
• Gasoline
• Batteries
• Cosmetics

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

What are some of the health effects associated with lead exposure?

The 2012 National Toxicology Program (NTP) literature-based monograph on health effects of low-level lead provides this information on health effects: Health Effects of Low-Level Lead.

Where is lead found now?

Lead can still be found in lead-based paint used in older homes, contaminated soil, household dust, drinking water pumped through leaded pipes, lead crystal, lead-glazed pottery, airplane fuel, some toys, and some inexpensive metal jewelry. Until 1978, lead paint was commonly used on the interior and exterior of homes. Deteriorated lead paint in older housing remains the most common source of lead exposure for children in the United States.

How does lead get into the body?

Lead can get into your body in two ways — through breathing it in or by eating it. For example, lead can enter the body through eating or inhaling paint dust or chips. The soil around your home can pick up lead from sources such as exterior paint. Lead can also enter your drinking water through your plumbing.

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 asNTP 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 Lead (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 the effects of lead in children?

Exposure to lead can have a wide range of effects on a child’s development and behavior. Blood lead levels less than 10 micrograms per deciliter (μg/dL) are associated with increased behavioral effects, delayed puberty, and decreases in hearing, cognitive performance, and postnatal growth or height. Some of these health effects are found even at low blood lead levels less than 5 μg/dL, including lower IQ scores, decreased academic achievement, and increases in both behavioral problems and attention-related behaviors. There is a wide range of lead-associated behavioral effects in the area of attention. Attention deficit hyperactivity disorder (ADHD) is one example on the more severe end of the spectrum.

What are the health effects of lead in adults?

Lead exposure has been linked to a number of health effects in adults. As a general rule, the more lead you have in your body, the more likely it is you’ll have health problems. High blood lead levels greater than 15 μg/dL are associated with cardiovascular effects, nerve disorders, decreased kidney function, and fertility problems, including delayed conception and adverse effects on sperm and semen, such as lower sperm counts and motility.

Blood lead levels below10 μg/dL are associated with decreased kidney function and increases in blood pressure, hypertension, and incidence of essential tremor, a degenerative disorder of the central nervous system whose most recognizable feature is a tremor of the arms or hands during voluntary movements, such as eating and writing. There is also evidence showing that adults who have low levels of exposure to lead less than 5 μg/dL may have decreased kidney function. Pregnant women need to be particularly careful around lead. Maternal blood lead levels less than 5 μg/dL are associated with reduced fetal growth. Because the effects of lead are different for everyone, more research needs to be done to fully understand the health effects.

A 2004 study, supported by NIEHS, also showed that lifetime lead exposure may increase the risk of developing cataracts,3 a clouding of the eye lens resulting in partial loss of vision, which can be common in older people.

Most adults with elevated blood lead levels are exposed to lead at work. Those in occupations related to mining, ironwork or welding, construction, renovation and remodeling activities, smelters, firing ranges, the manufacture and disposal of car batteries, automobile radiator repair, metal shop work, and the manufacture of pottery or stained glass are particularly at risk for lead exposure.

Are there treatments to remove lead from the body?

Yes, medications exist that can remove some lead from the body. However, no medical treatment is recommended for children with blood lead levels lower than 45 μg/dL. Medications, such as succimer, have been shown to significantly reduce lead in children with very high blood lead levels. Although succimer lowered blood lead about 25% in the short term, it did not improve IQ or other test scores. This reinforces the need for prevention. Treatment after the fact does not undo the damage caused by lead. Children must be protected from being exposed at all.

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	Children: Decreased academic achievement, decreased IQ, and decreases in specific cognitive measures, increased incidence of attention-related behaviors and problem behaviors Adults: Decreased kidney function, maternal blood lead associated with reduced fetal growth
Blood lead levels below 10µg/dL	Children: Delayed puberty, reduced postnatal growth, decreased IQ and decreased hearing Adults: 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
• Cataracts
• 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?

• If you live in an older home, check with your local health department about any lead that may be in the paint, dust, or drinking water. Professional cleaning, painting over old paint to stabilize it, and removal of hazardous building components, such as old pipes, can prevent lead exposure. All of these should be done by trained professionals and contractors certified by the EPA.
• Avoid storing food in imported pottery and dishware, as it may contain lead.
• Monitor recalled toys and jewelry by visiting theConsumer Product Safety Commission website, and remove recalled items from your home.
• If a household member works in a lead-related occupation, they should change work clothes and shoes before entering the home, and their work clothes should be washed separately.

For more information on chelation, please see these FDA pages:

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