What is lead poisoning?
Lead poisoning occurs when you absorb too much lead by breathing or swallowing a substance with lead in it, such as paint, dust, water, or food. Lead can damage almost every organ system.
In children, too much lead in the body can cause lasting problems with growth and development. These can affect behaviour, hearing, and learning and can slow the child's growth.
Although it isn't normal to have lead in your body, a small amount is present in most people. Environmental laws have reduced lead exposure in Canada, but it is still a health risk, especially for young children.
What causes lead poisoning?
Lead poisoning is usually caused by months or years of exposure to small amounts of lead at home, work, or daycare. It can also happen very quickly with exposure to a large amount of lead. Many things can contain or be contaminated with lead: paint, air, water, soil, food, and manufactured goods.
The most common source of lead exposure for children is lead-based paint and the dust and soil that are contaminated by it. This can be a problem in older homes and buildings.
Adults are most often exposed to lead at work or while doing hobbies that involve lead.
Who is at highest risk of lead poisoning?
Lead poisoning can occur at any age, but children are most likely to be affected by high lead levels. Children at highest risk include those who:
- Live in or regularly visit homes or buildings built before 1976. These buildings may have lead-based paint. The risk is even higher in buildings built before 1950, when lead-based paint was more commonly used.
- Are immigrants, refugees, or adoptees from other countries.footnote 1 They may have been exposed to higher lead levels in these countries.
- Are 6 years old or younger. Young children are at higher risk because:
- They often put their hands and objects in their mouths.
- They sometimes swallow non-food items.
- Their bodies absorb lead at a higher rate.
- Their brains are developing quickly.
Others at risk for lead poisoning include people who:
- Drink water that flows through pipes that were soldered with lead.
- Work with lead either in their job or as a hobby (for example, metal smelters, pottery makers, and stained glass artists).
- Eat food from cans made with lead solder. These types of cans aren't made in Canada or the United States.
- Cook or store food in ceramic containers. Some ceramic glaze contains lead that may not have been properly fired or cured.
- Eat or breathe traditional or folk remedies that contain lead, such as some herbs and vitamins from other countries.
- Live in communities with a lot of industrial pollution.
What are the symptoms?
You may not notice any symptoms at first. The effects are easy to miss and may seem related to other conditions.
In children, symptoms can include:
- Slightly lower intelligence and smaller size compared to children of the same age.
- Behaviour problems, such as acting angry, moody, or hyperactive.
- Learning problems.
- Lack of energy, and not feeling hungry.
In adults, lead poisoning can cause:
- Changes in behaviour, mood, personality, and sleep patterns.
- Memory loss and trouble thinking clearly.
- Weakness and muscle problems.
Severe cases can cause seizures, paralysis, and coma.
How is lead poisoning diagnosed?
The doctor will ask questions and do a physical examination to look for signs of lead poisoning. If your doctor suspects lead poisoning, he or she will do a blood test to find out the amount of lead in the blood.
Diagnosing lead poisoning is difficult, because the symptoms can be caused by many diseases. Most children with lead poisoning don't have symptoms until their blood lead levels are very high.
Whether your child needs to be tested depends in part on where you live, how old your housing is, and other risk factors. Talk to your child's doctor about whether your child is at risk and should be screened.
Adults usually aren't screened for lead poisoning unless they have a job that involves working with lead. For these workers, companies usually are required to provide testing.
If you are pregnant or trying to get pregnant and have a family member who works with lead, you may want to ask your doctor about your risk for lead poisoning. But in general, experts don't recommend routine testing for lead in pregnant women who don't have symptoms.footnote 2
How is it treated?
Treatment for lead poisoning includes removing the source of lead, getting good nutrition, and, in some cases, having chelation therapy.
Removing the source of lead. Old paint chips and dirt are the most common sources of lead in the home. Lead-based paint, and the dirt and dust that come along with it, should be removed by professionals. In the workplace, removal usually means removing lead dust that's in the air and making sure that people don't bring contaminated dust or dirt on their clothing into their homes or other places.
Good nutrition. Eating foods that have enough iron and other vitamins and minerals may be enough to reduce lead levels in the body. A person who eats a balanced, nutritious diet may absorb less lead than someone with a poor diet.
Chelation therapy. If removing the lead source and getting good nutrition don't work, or if lead levels are very high, you may need to take chelating medicines. These medicines bind to lead in the body and help remove it.
If blood lead levels don't come down with treatment, home and work areas may need to be rechecked. Call your local health unit or provincial ministry health to see what inspection services are offered in your area.
The best way to avoid lead poisoning is to prevent it. Treatment cannot reverse any damage that has already occurred. But there are many ways to reduce your exposure—and your child's—before it causes symptoms.
- Committee on Environmental Health, American Academy of Pediatrics (2005, reaffirmed 2009). Lead exposure in children: Prevention, detection, and management. Pediatrics, 116: 1036–1046. Also available online: http://www.pediatrics.org/cgi/content/full/116/4/1036.
- U.S. Preventive Services Task Force (2006). Screening for elevated blood lead levels in children and pregnant women. Available online: http://www.uspreventiveservicestaskforce.org/uspstf/uspslead.htm.
Primary Medical Reviewer John Pope, MD, MPH - Pediatrics
Brian O'Brien, MD, FRCPC - Internal Medicine
Kathleen Romito, MD - Family Medicine
E. Gregory Thompson, MD - Internal Medicine
R. Steven Tharratt, MD, FACP, FCCP - Pulmonology, Critical Care Medicine
Current as ofMarch 28, 2018
Current as of: March 28, 2018