From Staff Reports
(U-WIRE) BERKELEY, Calif. -- The popularity of bottled water and water filters such as Brita and Pur cause many people question the cleanliness and safety of drinking water out of the tap. Just thinking about all of the chemicals that run down the drain during chemistry lab may make a person think twice before taking a sip straight from the faucet.
Although bottled water companies and water filter producers boast the importance of clean water, the truth is that tap water is relatively safe to drink. Tap water comes from purification plants and has very low bacteria count. Low levels of chlorine present in tap water kills off bacteria and, in many cases, there are actually fewer bacteria in tap water than in most bottled waters.
The main difference between bottled or filtered water and tap water is that municipal tap water has chlorine residues, which serve to prevent recontamination of water as it moves through underground pipelines. Chlorine is strong enough to kill any bacteria that may invade the water. On its way from the treatment plant to the kitchen faucet, water can absorb a number of impurities and contamination can accrue through industrial and agricultural chemicals and other environmental waste.
The chlorine residue in water protects tap water as it flows through the winding pipelines, which would otherwise become a breeding ground for bacteria.
What water filter producers advertise, however, is the fact that while chlorination of municipal water supplies is necessary to kill and prevent bacteria as the water travels from the treatment plant to your tap, once you turn your tap on, you neither need it nor want it.
Many prefer to filter their water or to buy bottled water because the use of chlorine as a disinfectant causes a distinct and sometimes pungent taste and smell in water.
Chlorine makes some people nervous because a number of research studies draw links between long-term consumption of chlorinated drinking water and an increased risk of colon and bladder cancer. There is also growing concern about the long-term health implications of chlorine intake.
Research has shown that long-term exposure to certain by-products of chlorine may increase the risk of cancer, and bladder cancer in particular.
Studies have linked one specific by-product, called trihalomethanes or "THMs" to a significant increase in the risk of miscarriage in pregnant women who drank five or more glasses of unfiltered tap water a day.
THMs are a group of organic chemicals, which are suspected of being carcinogenic. They are formed in water when chlorine being used as a disinfectant reacts with natural organic matter (such as humic acids from decaying vegetation).
A Brita water filter claims to remove 99 percent of chlorine as well as heavy metals in tap water such as lead and copper which can be caused by the household installations. The filters also eliminate fluoride, which may not be a benefit for children's teeth.
Brita, however, does not filter THMs out of tap water.
Tap water may be just as safe because chlorine and THMs evaporate from tap water after a few hours.
The benefits of a Brita water filter lays in its ability to filter out heavy metals and other impurities, such as lead, which are most likely not in your tap, but may be due to poor plumbing.
Some studies have shown that home plumbing may be a source of excessive levels of lead. Impurities such as organic matter, sediment, rust and lead can be absorbed in the water ways and plumbing system, especially when using hot water from the tap.
Brita uses reverse-osmosis and consists of a two-tiered pitcher and a carbon and resin filter. Water poured into the top tier passes through the filter into the bottom tier, taking three to five minutes to filter a quart of water.
In terms of bacteria, however, Brita water filters do not aid to kill the microorganisms. If you have not changed your filter in six months, the Brita filter becomes useless.
Brita traps, but does not kill bacteria. Because the filter cannot kill bacteria, it actually becomes a breeding ground for the microorganisms if not changed regularly. An old, unchanged Brita filter can be dangerous because its use may add bacteria, which had been killed in the tap by chlorine, back into water.
So, the bottom line is that if you have a clean Brita filter, it is fine to use it for better tasting water and to take extra precaution. But for those concerned about chlorine levels, you can also go ahead and drink the tap as well. Chlorine is a fat-soluble compound and just as much enters your body when you take a shower as when you drink it directly.