Is It Best to Drink Tap, Filtered, or Bottled Water?


“Is It Best to Drink Tap,
Filtered, or Bottled Water?” Though many distrust
the safety of tap water, a study of 35 brands of bottled
water did not find them to necessarily be safer,
cleaner or of higher quality than water straight
out of the faucet. How much is that saying, though? Two studies published back in the
1970s forever changed our perception that drinking water safety was
only about waterborne diseases. In fact, it was our fight
against microbial contaminants that led to a new kind of contamination
in the form of disinfection byproducts. The two landmark papers
in ‘74 solved the mystery of the source of chloroform
in drinking water: We met the enemy and he is us. The chlorination of drinking water— crucial for maintaining
microbiological safety— was interacting with natural organic
matter from the water’s source and creating chlorinated compounds
that can not only result in off-flavors and smells, but pose
a potential public health risk. More than 600 disinfection byproducts
have so far been identified. After decades of research into
the matter, it appears that the life-long ingestion of
chlorinated drinking water results in “clear excess
risk” for bladder cancer. There is also some evidence of
increased risk of certain types of birth defects but most of the concern
has focused on the bladder cancer link. Forty years of exposure may increase your odds of bladder
cancer by 27 percent. The Environmental Protection Agency
estimated that between 2 to 17% of bladder cancer cases in
the United States are due to these disinfection
byproducts in drinking water. However, this is assuming
the link is cause-and-effect, which has yet to
be firmly established. The best way to reduce risk
is to treat the cause. Countries could prevent the
formation of disinfection byproducts in the first place, through
the better initial removal of source water’s
“natural organic matter” (or what my grandmother would
have called “schmutz”). Some countries in Europe, such
as Switzerland, have newer, well-maintained drinking-water systems that can distribute tap water free from residual disinfectants, but the cost to upgrade the infrastructure of even a small city here in the U.S.
could run in the tens of millions. As the Flint tragedy revealed,
we seem to have trouble keeping even frank toxins
out of the tap. Nearly 40 percent of Americans use
some sort of water purification device. Two of the most common
approaches—pour-through pitchers and refrigerator filters—
were put to the test, head-to-head against Tucson tap water. Both of the fridge filters
(GE and Whirlpool) did similarly well, removing more than 96 percent
of trace organic contaminants, edging out the three pitcher filters. Zerowater brand caught 93 percent,
PUR pitchers got 84 percent, but by the time the filters
needed to be replaced, Brita was only catching 50 percent. A similar discrepancy was found
between PUR and Brita brand filters tested specifically against
disinfection byproducts. They both started out about
the same at the beginning, but by the end of the filter’s
life PUR appeared to do better. Reverse osmosis systems
can work even better, but the cost, water waste, and loss of
trace minerals doesn’t seem worth it. The annual cost for purifying your
water with the pitcher or fridge filters was calculated out to be about the
same, at only around a penny per cup— with the exception of
the ZeroWater brand, which is up to four times more expensive. I always figured the “change by”
dates on the filters were just company scams to get
you to buy more, but I was wrong. Since I drink filtered
water mostly just for taste, I used to just wait until the
water started tasting funky. Bad idea. Not only do the filters
eventually lose some of their removal capacity, bacterial
growth can build up inside them, resulting in your
so-called “filtered” water having higher bacterial counts than the water straight out of the tap. You’d be actually making your
water dirtier rather than cleaner; so, it is important to
replace them regularly. As an aside, I used to think
the same thing about the advice to change your toothbrush
every three months. Like, which Big Brush
executive thought of that one? But no, wrong again. Toothbrushes can build up biofilms of tooth decay bacteria or become
breeding grounds for bacteria flumed into the air
with each toilet flush before going back into our mouths. Fun Fact: A single flush can
spew up millions of bacteria that can settle on
your nice moist brush. The good news is that
rather than buying new ones you can just disinfect
the head of your toothbrush, with as little as a 10-minute
soak in white vinegar, or even more frugally, vinegar
diluted in half with water.