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Tough yet malleable and easy to bend and work with, lead became the chosen metal for water pipes long, long ago—a use that dates back to the ancient Romans. However, lead is notoriously dangerous, with medical and public health experts agreeing that there is no safe level of lead in the human body. Then, how does lead get into our tap water? It enters drinking water when a chemical reaction occurs in plumbing materials that contain lead. This is known as corrosion-dissolving or wearing-away of metal from the pipes and fixtures. This reaction is more severe when water has high acidity or low mineral content. Because we cannot see, taste, or smell lead in drinking water, the best way to know the risk of exposure to lead in drinking water is to identify the potential sources of lead in the service line and household plumbing. The local water authority is always the first source for testing and identifying lead contamination in the tap water. Here are a few suggestions for homeowners to cope with the problem:
-First and foremost, ask your water provider if you have a lead service line providing water to your home. If you have a lead service line, ask if there are any programs to assist with removal of the lead service line going to your home.
-You should be aware that any work, such as water main or service line replacement, could increase exposure to lead while the work is ongoing and for up to six months after the work is completed.
-You should ask to have your water tested. Many public water systems will test drinking water for residents upon request. There are also laboratories that are certified to test for lead in water.
-You need to understand that water sampling results can vary depending on the time of day, season, method of sampling, flow of water and other factors.
According to the passage, why did lead become a chosen material for water pipes?
AIt is strong and pliable.正確答案
BIt is solid and dense.
CIt is heavy and compact.
DIt is resistant to corrosion.
答案與詳解
