Sunday, March 21, 2010

Can We Drink or Cook with Hot Tap Water?

Has anyone watched the first season of Hell's Kitchen? Remember that Chinese contestant embarassed herself and got kicked off the show, after she said "cold water boils faster than hot water". My mother has always taught me to never use hot tab water to cook food. I have no idea why, but it was a cardinal sin, but when I worked in restaurant, the chef there used hot water to cook. Is hot tap water is safe for drinking and cooking?

A quick googling would tell you that hot water increases the rate in which lead inside the water pipe is leached into the water. For most people, the research would stop here and they would go on with their life being fearful of hot tap water and tell their kids to do the same. Those kids would probably then grow up and get kicked out of Hell's Kitchen. Being really stubborn, I couldn't accept that government would really allow lead in pipes, and I could actually get lead poisoning from eating at restaurants, so I researched further.

Guess what? In Canada, there is a legal limit for lead content in drinking water, measured at the tap, and the maximum concentration is calculated for the consumption of water over the course of a life time of 70 years, regardless of the temperature of the water. Since 1975, it was illegal to use lead as material for pipes, and in 1986, it was illegal to use it in solder. If your house or water heating appliances are more than 24 years old, there are probably a low level of lead in your drinking water and, yes, higher level of lead in hot water. If your house or water heating appliance are more than 35 years old, well, you are ingesting the same amount of lead regardless the temperature of your water. Time to replace some pipes or that water heater. For newer houses, there are no differences in the amount of lead in hot or cold tap water, even if the service pipe in your community is old.

Here is what we have learned:
1. Regardless how old the pipings are, the amount of lead consumed over a 70 year period is not known ot cause any health risk.
2. Even if lead is being leaked into water, the temperature of the water does not matter. Same amount will be leaked even in cold water.

We have been asking the wrong question. The question we should be asking is: how old is your house and water heating appliances? If they are much older then you or you suspect some defects, don't drink hot tap water. Otherwise, go ahead and save yourself a few minutes boiling water.

Most of UBC are newly developed and my apartment is only 3 years old. I think I am safe. The hot water at Hell's Kitchen is definitely safe to use for cooking.

No comments:

Post a Comment