Simple ways to prevent contamination – Health Canada limits the lead content in drinking water to 10 parts per billion in a sample of running water. This means that the municipal water supply contains virtually no lead. So how does lead contamination occur and how can we protect ourselves?

Harmful effects on health despite many benefits

Malleable, ductile, affordable and easy to weld, lead has been used in plumbing since ancient times. However, it is very harmful to human health. Some historians even argue that lead contamination could be partly responsible for the fall of the Roman Empire!

A minimal amount of lead in the blood affects human health to varying degrees. Between 10 and 15 micrograms of lead per deciliter of blood can have harmful effects on the neuro-behavioural and cognitive systems in children and fetuses, while a level of more than 40 micrograms can interfere with the production of red blood cells. Cases of lead poisoning, at very low doses, are difficult to identify and that is why very few are recorded in Canada.

Lead contamination

Contamination occurs within buildings, where lead can be found in certain connections, plumbing fixtures and in welds. It mainly occurs when the water remains stagnant for more than 6 hours in pipes where there is the presence of lead, which then dissolves in the water. Hotter is the water, higher is its dissolving power.

Older homes, especially those built before 1955, are more at risk because the water connections were, at the time, made of lead.

Since then, the standards and requirements governing the use of lead in plumbing have continued to evolve. Recently, in 2014, the concentration of lead in taps and plumbing fixtures used for the distribution of water intended for human consumption was reduced to 0.25%.

Safety measures

Domestic equipment exists to decontaminate the water, including carbon filters installed directly on the tap, reverse osmosis purification systems and distillation units. Some of these equipment are expensive and require regular maintenance.

It is therefore recommended to perform these very simple actions which can make a difference:

  • Let the water run for a few minutes after a 6-hour period of non-use,
  • Cook in cold water,
  • Regularly clean the faucet aerator.
How to identify a lead connection

Find the shut-off valve for the main water inlet and observe the pipe. The lead is grey, it does not resonate if you hit it and leaves metallic marks when you scratch it. It does not attract a magnet.

Do not hesitate to call a specialist to identify potentially risky plumbing lines.

Source: Health Canada