Description
Lead is a metal that is found in small amounts in our environment, including in water, air, soil and consumer products.
Nowadays, sources of lead in the environment have decreased a lot, but there are still some left. In order to minimize the health risks, public health authorities recommend the lowest possible exposure to lead. To find out more, go to the Reducing exposure to lead page.
Lead exposure
Everyone is exposed to small amounts of lead.
Lead that enters the body goes into the bloodstream and then into the bones and some organs, such as the brain and kidneys. Although some of the lead is excreted in urine and stool, a significant amount accumulates in bones and teeth over time. The concentration of lead in the body can vary widely from person to person. With aging and decreasing bone mass or during pregnancy, the lead that has accumulated goes back into the bloodstream. It takes the body around 25 years to excrete half the accumulated lead.
Some people are more likely than others to be in contact with lead:
- those who use certain consumer products;
- those who eat game meat contaminated with lead ammunition;
- those who use or make lead ammunition or who visit shooting centres;
- those who work in environments where lead is found, such as:
- smelters,
- refineries,
- the recycling sector;
- families exposed to contaminated clothing and equipment brought home by a worker.
Lead exposure is detected by doing tests to measure lead in the blood. These tests are done when significant lead exposure is suspected, for example in the workplace.
Health effects of lead exposure
Lead is harmful to everyone’s health, regardless of age.
Nowadays, harmful effects from significant short term lead exposure are very rare. Indeed, severe measures have been put in place in workplaces, for instance, where exposure could occur.
The symptoms observed with prolonged lead exposure vary widely and are not very specific. Depending on the amount of exposure, lead can cause problems, for instance, in:
- the cardiovascular system (increased blood pressure);
- the kidneys;
- cognitive function (e.g., impaired concentration or memory);
- the blood.
Possible neurodevelopmental effects from regular lead exposure in children are:
- a slight decrease in intelligence quotient;
- mild effects on learning skills;
- impulsivity and attention problems such as attention-deficit/hyperactivity disorder (ADHD).
Vulnerable populations
Some population subgroups are particularly sensitive to the effects of exposure, even to low concentrations of lead in the environment:
- pregnant women, for the unborn child;
- infants;
- young children.
Unborn child
During pregnancy, it is important to avoid sources of lead exposure in order to protect the unborn child. The lead absorbed by the mother can get into the baby’s bloodstream and have harmful effects on its health. In particular, the baby’s weight might be lower.
Infants
Breastfed infants are exposed to low levels of lead in breast milk. In general, the benefits of breastfeeding still outweigh the low risk of health effects. The water used to prepare milk formula can also be a source of lead in some homes.
Children
Unborn children, infants and children are more sensitive to the effects of lead on their nervous system. Indeed, they absorb lead more easily than adults and their brain is developing. Children who consume food or water that may contain lead could have mild effects on their learning skills.
Children under 6 years of age are vulnerable because they play or crawl on the ground. Their main sources of exposure are soil and the ingestion of dust at home, since they have the reflex of bringing anything in their hand to their mouth. So exposure to lead comes mainly from household dust, food and drinking water. These sources contribute to the small amount of lead found in the blood of all children.
Nowadays, however, children’s exposure to lead is much lower. Efforts to discontinue the use of lead in paint, gasoline and plumbing have contributed to this.
Although the exposure of the population to lead has decreased significantly in Canada, this is not the case for everyone. Newcomers with high blood lead levels may have been exposed in their country of origin.
Source : Tétreault, L.-F., Brodeur, J. et Beausoleil, M., 2017. Plomb dans l’eau potable de l’île de Montréal : concentrations de plomb dans l’eau potable des écoles et évaluation des risques à la santé des enfants de 5-6 ans.
Direction régionale de santé publique du CIUSSS du Centre-Sud-de-l’Île-de-Montréal.
When to consult
If you think you have been exposed to a significant source of lead during an activity or at work, share your concerns with your doctor.
Depending on the situation, they may do a blood test to check if you have been exposed to an excessive level of lead.
Treatment
If your blood lead concentration is high, treatment to accelerate its removal may be recommended. The type of treatment offered varies depending on the concentration of lead in your blood and your health. In all cases, potential sources of lead in the environment must be identified and removed to reduce your exposure.
Reportable disease
In Québec, lead exposure is a reportable disease of chemical origin. If your blood lead level exceeds recognized public health thresholds, your doctor will have to report the situation to the public health department in your region to help identify the source(s) of exposure and to ensure that other people around you are not exposed.
Protection and prevention
Trace amounts of lead can be found everywhere in our environment. Even if the main sources of contamination have been eliminated, such as lead in gasoline, paint and food can solder, it is recommended that exposure to lead be minimized. To find out more about sources of exposure and precautions, go to the Reducing exposure to lead page.
Lead in water in schools and childcare services
Drinking water in schools and childcare services is one of many sources of lead exposure. In general, the risk of health effects associated with lead in water in schools and childcare services is low, since:
- most of the time, the amount of lead decreases or disappears after letting the water run a little;
- children drink less water at school or daycare than at home;
- as a precaution, the water in schools or childcare services is tested when the amount of lead should be at its highest (after it has been stagnant for a long time). So the results of these tests do not represent what children drink the rest of the day.
No medical follow up is needed for your child in relation to lead in water of schools and childcare services. They do not need a blood test for this type of lead exposure. The Direction régionale de santé publique will notify the parents concerned in the event that special follow up is necessary.
To find out more, go to the Lead in the drinking water of educational institutions page.
Last update: November 19, 2025