Lead and Drinking Water
Lead is a soft, silvery-grey heavy metal that has been used since Roman times for many useful purposes. Unfortunately, lead is also quite toxic to people, especially children.
Where is Lead Found?
Lead is mined from rocks and soil. The most common sources of human exposure to lead are paint, soil, and dust. The primary source of lead in drinking water is household plumbing that can introduce lead from lead pipes, lead solder, or fixtures with lead alloys such as brass. Lead can also be found in the piping and submersible pump systems used in private wells. Lead levels in drinking water increase with acidic and soft water and with the length of time the water is left standing in a leaded plumbing system. Lead plumbing was eliminated from new construction in the 1950s and lead solder was banned in the late -1980s.
Is Lead a Health Concern?
The maximum acceptable concentration for lead in drinking water is 0.01 mg/L (Ontario Drinking Water Standards). Although high concentrations of lead can be harmful to all people, fetuses and children up to six years of age are most susceptible to the adverse health effects of lead. Studies show that exposure to even low levels of lead prior to birth (e.g., as a fetus) or during early childhood can cause damage to intellectual and behavioural development.
Water with lead levels above 0.01 mg/L should not be used to prepare powdered or concentrated baby formula. If your water does have elevated lead levels, you should prepare baby formula with water from an alternative source that is known to be safe.
The safest source of water for all those at risk is a municipal drinking water supply that has not been delivered through lead pipes.
What can I Do?
Determine if your plumbing contains lead and consider replacing some or all lead piping. If you rent an older apartment or old house (built before the mid 1950s), ask your landlord about having the pipes replaced. If you have lead plumbing, do not use water from the hot water tap for drinking or cooking. Hot water dissolves lead more quickly than cold water. If water has been standing in pipes for more than five hours (e.g., overnight) it should be run for at least five minutes or until the water turns cold. This flushing only needs to be done for water used for drinking and cooking.
Can I Test For Lead?
Water can be tested for lead. Home test kits available at many plumbing and hardware stores only test for the presence of lead and should not be relied upon to provide actual lead levels. For an actual lead level, a sample must be sent to a professional analytical laboratory for analysis. Contact your local municipality to find out if a lead testing program for municipal water is available.
For more information contact a Public Health Inspector:
458 Laurier Blvd
25 Johnston Street,