Lead Poisoning

by Elizabeth Smoots, MD

Definition

Lead is a toxic metal. In adults, lead poisoning happens when levels of lead in the blood increase. The Occupational Safety and Health Administration (OSHA) requires that workplaces take action when a worker’s blood lead level is too high. This means more than 25 micrograms per deciliter (mcg/dL) in the blood. Lead is very common in the environment. As a result, most adults have some level of this metal in their blood and body tissue.

Experts believe that no level of lead in the body is safe for children. Concern about lead poisoning in children occurs when lead reaches a level of 10 mcg/dL in the blood. Levels of 20 mcg/dL or more represent actual lead poisoning. This can lead to:

Lower levels of blood lead (probably below currently accepted "safe" levels) can lead to learning and/or behavioral difficulties. They can also delay puberty in boys.

Causes

Lead can be absorbed into the bloodstream by eating, drinking, or breathing contaminated particles.

Lead is used in many industrial processes and within the home. It can be found in:

  • Paint
  • Dust
  • Soil
  • Drinking water
  • Food (rarely)

Most homes built before 1960 contain some lead-based paint. This was banned from residential use in 1978. Dust containing lead can linger on windowsills and in window wells. Drinking water that travels through lead pipes, or through pipes with lead-based soldering, may also be contaminated. Lead can become mixed with dirt after it peels from paint on building exteriors. Industrial sources and car exhaust also contribute to the problem. Lead levels in the air have dropped a lot since lead additives were banned from gasoline in the 1970s. Food produced outside of the United States can be contaminated if packaged in lead-soldered cans.

Risk Factors    TOP

A risk factor is something that increases your chance of getting a disease or condition.

Risk factors for lead poisoning include:

  • Work in an industry employing or processing lead
  • For children:
    • Age: 6 or younger
    • Living in a house or apartment built before 1960
    • Living in neighborhoods where homes were built before 1960
    • Living in a home with adults whose work or hobbies put them in contact with lead
    • Receiving transfusions from adults who have relatively high lead levels in the blood—This is a special risk for very small infants receiving newborn intensive care.
    • Being born to a mother who has high levels of lead stored in her bones—Pregnancy often causes this lead to move from the bones to the bloodstream. It may cross the placenta and affect a developing baby.
    • Breast milk may also contain lead. Nursing mothers who live in houses with lead hazards may transmit lead to their babies through breastfeeding.

Placenta Blood Flow

Placenta Function
Copyright © Nucleus Medical Media, Inc.

Symptoms    TOP

People with lead poisoning often show no symptoms. However, the toxic metal can negatively affect nearly every system in the body.

One of the most serious concerns is lead's harmful effect on the neurological system. For every 10 mcg/dL increase in blood lead levels, there is a 2-3 point decline in IQ test scores. Lead poisoning is also associated with neurodevelopment problems, such as:

Other possible signs of lead poisoning include:

  • Headache
  • Pain or numbness in the extremities
  • Muscle weakness
  • Nausea and vomiting
  • Loss of appetite, abdominal pain
  • Impaired hearing
  • Memory loss
  • Fatigue
  • Sleep disturbances
  • Mood disorders
  • Kidney damage
  • Dental and bone abnormalities

Diagnosis    TOP

Your doctor will ask about your symptoms and medical history. A physical exam will be done. Lead poisoning is diagnosed with a blood test.

The Centers for Disease Control and Prevention (CDC) recommends that children at high risk for lead poisoning have their blood levels tested. This should be done at 12 and 24 months (or at 24 and 36 months if not tested earlier). High-risk children are defined as those receiving Medicaid. For other children, the CDC recommends that each state develop its own testing plan. Each plan will be based on local experience with lead poisoning.

The American Academy of Pediatrics recommends screening at age one and two for children who live in high-risk areas. These include areas where 27% or more of housing units were built before 1950. Or, in which at least 12% of tested children have elevated lead levels. Testing is also indicated if a sibling has had lead poisoning, or a parent has contact with lead through work or hobbies. If you or your child has lead levels higher than 10 mcg/dL of blood, seek immediate medical treatment.

Treatment    TOP

Treatment depends on the severity of lead poisoning.

Treatment may include:

Environmental Controls

If you have mild-to-moderate lead poisoning (20-44 mcg/dL), you may not be given medication. Doctors will work with social workers and public health officials to eliminate lead in your home, workplace, and school. They then carefully monitor blood levels until the lead naturally works its way out of your system.

Medications

If you have moderate lead poisoning (in some cases) or severe lead poisoning (45-69 mcg/dL), you will need medication. Medications may include oral or IV chelating agents that bind to lead and speed its removal from your body in your urine. Blood levels above 70 mcg/dL are considered acute cases. Hospitalization and emergency medical treatment are necessary.

Prevention    TOP

Take the following steps to decrease the risk of lead poisoning for yourself and your children:

Avoid Lead

  • Have your home's paint and water tested if:
    • You live in a home built before 1960
    • You think you are being exposed to lead
  • Safely remove any lead you find. Your state's Department of Public Health will help with this process.
  • Keep young children away from peeled or chipped paint.
  • Wash children's toys regularly.
  • Make sure children wash their hands before eating.

Keep It Clean

Try not to vacuum hard surfaces. Instead, use wet wipes or lead-absorbing detergents to avoid spreading lead-filled dust. Vacuuming with cleaners that employ HEPA air filtration may be safe and effective for floors and other hard surfaces. Eliminating lead hazards usually requires window replacement and careful surface repainting. Lead-containing dust tends to accumulate in carpets. Until further evidence about effective carpet cleaning becomes available, replacement of carpets is the only known way to reduce risks from floor coverings. When outside dirt is contaminated, it may need to be dug up and replaced with clean soil.

Play in Safe Areas

Take the following precautions:

  • Encourage children to play in grassy areas instead of dirt.
  • Keep children away from foundations of older homes where peeling paint may have contaminated the surrounding soil.
  • If there is a chance of lead exposure outside the home, have everyone take off their shoes before coming inside.
  • Certain adult hobbies can expose children to lead poisoning. These include:
    • Making stained glass (where lead is involved)
    • Soldering electrical devices with lead-containing solder
    • Fishing with lead-containing “sinkers”

Parents who work with lead or whose hobbies involve lead should take special precautions to protect themselves and their children from lead contact.

RESOURCES:

National Safety Council's Environmental Health Center
http://www.nsc.org
United States Environmental Protection Agency
http://www.epa.gov

CANADIAN RESOURCES:

About Kids Health
http://www.aboutkidshealth.ca
Canadian Centre for Occupational Health and Safety
http://www.ccohs.ca

References:

Bearer CF, O'Riordan MA, et al. Lead exposure from blood transfusion to premature infants. J Pediatr. 2000;137:549-554.
Centers for Disease Control and Prevention website. Available at: http://www.cdc.gov.
Lead poisoning. Mayo Clinic website. Available at: http://www.mayocli.... Updated April 8, 2009. Accessed June 10, 2009.
Lead Poisoning Prevention Program website. Available at: http://www.epa.gov/lead.
Lozoff B, Jimenez E, et al. Higher infant blood lead levels with longer duration of breastfeeding. J Pediatr. 2009 Nov;155(5):663-667.
National Safety Council Environmental Health Center website. Available at:
...(Click grey area to select URL)
Ronchetti R, Van Den Hazel P, et al. Lead neurotoxicity in children: is prenatal exposure more important than postnatal exposure? Acta Paediatr. 2006;95:45-49.
7/2/2010 DynaMed's Systematic Literature Surveillance https://dynamed.ebscohost.com/about/about-us: Williams PL, Sergeyev O, Lee MM, et al. Blood lead levels and delayed onset of puberty in a longitudinal study of Russian boys. Pediatrics. 2010;125(5):e1088-1096.
Last reviewed September 2012 by Kari Kassir, MD
Last Updated: 09/28/2012