I've been a swimmer all my
life. When I became pregnant, along with the nausea came a little voice
telling me to stay out of the pool. I
stopped swimming. After my son was born, I returned to my daily laps but
began to give more than a passing thought to the strong odour emanating from our
recreation centre pool.
A bit of Internet
research turned up numerous sources saying that young children exposed to
chlorinated pools were more likely to develop asthma than children who were
not. I continued swimming but began to look with sadness at the beautiful
babies (our pool allows children from 3 months onward) being brought to ‘swim’
by their unsuspecting parents. I even asked a pediatrician if chlorine
was dangerous for children. The Dr.'s response was that the social
benefits of swimming far outweigh the potential dangers of chlorine.
I wanted to believe
her. Truly. But my nose told me not to. So, when my son's
friends started swimming lessons at local indoor pools, we put our son into
other sports. This made me sad for many reasons: swimming is a crucial
life skill, fabulous exercise and lots of fun.
The summer our son turned
2 we took him for lessons at our outdoor community pool. We have done this every summer since. I reasoned
that he might learn more slowly but at least the pool was well ventilated.
Funny. I hadn’t planned to write about this until I
saw the article below, written by Francesca Lyman, on the MSN Green page today.
Far from feeling satisfied that my instincts were correct, I wish I had been
wrong on this one.
Avoiding Chlorine's Sting
By Francesca Lyman
One minute the swimmers were weaving through an eight-lane
loom of water like dolphins, to the delight of thousands of howling and
whistling fans. The next minute some were gasping for air.
When more than 35,000 of the nation’s biggest swim fans and
top swimmers, including Olympian Michael Phelps, came to the U.S. National
Swimming Championship last year in
Indianapolis
,
the thick smell of chlorinated chemicals coming off the pool caused athletes to
suffer breathing problems, red eyes and headaches. Some walked out of warm-ups
on the first day of the meet, waiting until a ventilation problem was
corrected, because the air was so bad.
Anyone who has ever swum in a chlorinated pool knows
firsthand the harsh effects that chlorine can have on eyes, skin and hair. But
the more serious “lifeguard lung” and “swimmers asthma” conditions linked to
these chemicals are becoming a hot-button issue for public health agencies,
according to Michael Beach, a specialist in recreational waterborne illnesses
at the Centers for Disease Control and Prevention (CDC). “This is an emerging
health concern that is really about chemicals accumulating above the pool,
‘off-gassed’ from the water into the air swimmers are breathing,” says Beach.
Something in the Air
Chlorine is good for killing many waterborne bacteria that
carry diseases. But it reacts with organic matter -- everything from the leaves
and dirt that land in outdoor pools, to what people put into them, like sweat,
oils, lotions and urine -- to form dozens of so-called disinfection byproducts,
or DBPs. When pools are poorly maintained or badly ventilated, these chemicals
can irritate skin, eyes and respiratory tracts—and more.
In recent years, more studies have linked these chemicals to
"lifeguard lung" and "swimmers asthma." In one June 2007
study published in Pediatrics, for example, scientists found that children who
swam regularly were more likely to have asthma and lung-cell damage, some as
bad as adult smokers. “Because their lungs are still developing, infants could
be particularly sensitive,” lead researcher Alfred Bernard with the Catholic
University of Louvain in
Brussels
wrote, “despite the rather limited time they spend in [the] pool (usually 20 to
30 minutes per session).”
Since DBPs were discovered in chlorinated tap water in 1979,
the Environmental Protection Agency stepped in to limit levels of these
chemicals, which have been linked to cancer, miscarriages and other health
problems. But no such limits exist for swimming pool water. Yet researchers
with the Center for Research in Environmental Epidemiology at the University of
Barcelona found that swimming in a chlorinated pool increases one’s risk of
bladder cancer; moreover, lead researcher Cristina M. Villanueva, writing in
the January 2007 issue of the American Journal of Epidemiology, found that when
DBPs like trihalomethanes are absorbed through the skin or lungs, they are more
carcinogenic than when chlorinated water is ingested because they aren’t
detoxified by the liver.
What’s that smell?
While most people assume that the strong odor of a pool is
coming from the chlorine, it’s actually these disinfection byproducts that are
created as the chlorine oxidizes organic matter in the pool. So it’s not a case
of too much chlorine as it is poor sanitation in the pool to begin with, according
to Tom Lachocki, director of the National Swimming Pool Foundation (NSPF).
Scientists and organizations like the NSPF are only just
beginning to analyze the chemical soup in swimming pools. So far, hundreds of
disinfection byproducts have been identified, and more are being discovered all
the time.
In
Europe
, where public awareness of
pool health issues is much more in the cultural mainstream, chlorine use is
much lower than it is in the
U.S.
Some countries are "almost chlorine-phobic," says Roy Vore, a
microbiologist with Dupont de Nemours’ Chemical Solutions Enterprise.
"Their water treatment regimes are more sophisticated, and they work at
replenishing the water, using flocculation and filtration and encouraging a
culture of showering and bathing." By contrast, Americans are hardly aware
of the problem, although they play a big role in it through their habits of
hygiene, Lachocki insists.
Mounting Violations
Still, pool operations and maintenance leave a lot to be
desired, according to the CDC. In a survey of 22,131 inspections of pools in
selected states done in 2002 (the most recent to date), the agency found 21,561
violations of pool codes. More than half of the pools inspected had at least
one violation, many related to water chemistry (38.7%), and filtration and
recirculation systems (38.6%). Some of the violations were so serious that
pools (in more than 8 percent of cases) had to be immediately shut down.
Meanwhile, some cities are mounting their own
investigations; the Orlando Sentinel and Los Angeles Times newspapers have both
exposed flagrant violations of basic sanitation in their regions’ pools.
"Most states don’t require pool operators to be trained, and that’s a big
problem," says Lachocki.
Others fear, however, that serious problems are emerging
even when pools are being kept to customary health standards. For example, a
2004 study presented by the
American
College
of Sports Medicine found that athletes who swam in water chlorinated at
concentrations typically found in home and public pools suffered
“exercise-Induced asthma” more than 60 percent of the time.
Help on the Way
Health studies like these are spurring interest among
consumers in non-chlorine or low-chlorine methods, like ozone, ultraviolet and
mineral sanitizers, and ionization, say industry-watchers (see our breakdown of
chlorine alternatives at the end of this article).
"People really hate chlorine -- that it gives them
burning eyes, smells bad, wrecks their hair, stings their eyes," says Beth
Hamil of DEL Ozone in San Luis Obispo, Calif., a major installer of ozone
systems for swimming pools. "The skin is the largest organ of your body;
don’t think your skin isn’t sucking up those chemical byproducts!"
Help is on the way, at least at the University of Indiana/Purdue
University at
Indianapolis
, where
the
U.S.
national swimming champions confronted breathing problems last July. This
summer, at "the Nat," says Natatorium Director Julie McKenney,
they’ve gone beyond fixing the ventilation system, which averted a major
emergency: "We’ve also now installed an ultraviolet radiation system that
will do a great job of making the water as clean and safe as possible."
A Swimmer's Guide: 5 Tips for Healthier Swimming
So, what can swimmers do to protect themselves? Here are
five tips from the Centers for Disease Control and Prevention and from the
Aquatics Safety Research Group:
· Before you dive into that pool, make sure the
water looks clean and that there’s no odor.
· Ask your pool operator if water chemistry is
tested, especially on weekends when the pool is most crowded. Ask for the
levels of chlorine and pH. Chlorine levels should ideally be between 1 and 4
ppm, but no more than 5 ppm. The pH level should be between 7.2 and 7.8
(ideally 7.4, the pH of human tears).
· Ask your local health department about their
standards for pool inspection. Find out what the pool inspector’s grade was
after the last inspection of your pool. You can also check your local codes for
swimming pools and spas at the National Swimming Pool Foundation Web site.
· Until more is known about the links between
asthma and regular pool use by young children, pediatricians advise parents to
minimize their children’s exposure to heavily chlorinated pools, especially
indoor pools or those with inadequate ventilation.
· Those signs graciously asking you to
"shower first" to remove sweat, dirt and lotions? Obey them! It’s not
just good hygiene; it prevents the formation of cancer-causing chloramines. If
everyone showered before swimming, some pool chemists claim, it would cut the
need for chlorine in half.
Chlorine Alternatives: A Side-by-Side Look
Chlorine is by far the most widely used method for
disinfecting swimming pools in the
United States
-- and has been for decades. But the discovery that chlorination can result in
the formation of certain disinfectant byproducts, such as trihalomethanes like
chloroform, and chloramines (which may trigger or cause asthma and respiratory
irritation, and potentially lead to some cancers over the long term) -- has
spurred growing interest in alternatives. Plus, chlorine is ineffective in
killing many pathogens on the rise.
U.S.
swimmers competing in the 2008 Olympics will plunge into
Beijing
’s
“Water Cube,” an eco-friendly, state-of-the art swimming complex in which the
water is purified with high-capacity ultraviolet-radiation and, to a lesser
extent, chlorine.
Here are four alternatives that can be used to either
replace or reduce the use of chlorine.
Ozone
What it is: Three oxygen atoms bound together; injected into
the water circulation system; used extensively in
Europe
Advantages
Can inactivate Giardia and Cryptosporidium (which are
chlorine-resistant).
When supplemented with chlorine, can eliminate chlorine byproducts; can also be
used in conjunction with UV.
Disadvantages
Can purify water as it is piped into a pool, but it does not
leave a residual disinfectant. So it needs either a mineral system backup or a
chlorine residual (or both) to protect against algae and disease-causing
pathogens.
Ultraviolet Radiation
What it is: Short-wave radiation strong enough to kill
viruses, bacteria and parasites; circulating water is passed through a UV
chamber.
Advantages:
Keeps chloramine levels very low.
Can inactivate pathogens like Crytosporidium and Giardia (which are
chlorine-resistant).
Disadvantages:
Like ozone, UV radiation purifies the pool water as it
passes through the UV-lamp chamber but doesn’t leave a residual disinfectant.
Requires UV lamps, which need to be maintained and replaced.
Saltwater/Chlorine Generator
What it is: An electrolytic cell breaks down salt (NaCl) and
releases chlorine into the water; after salt is added directly to the pool or
spa it is passed through an electrolytic cell, producing chlorine.
Advantages
Operators don’t have to buy or handle chlorine in liquid or
gaseous form (when it is most toxic and explosive).
Anecdotal data suggests fewer people report allergic reactions to saltwater
pools than to "normal" chlorine pools; less reports of eye-stinging
or smells.
Disadvantages
Because chlorine is still present, disinfectant byproducts
(chloramines, chloroform, etc.) are still created and can linger in the water
and the air.
Ionizers
What it is: Uses copper and silver ions, as well as zinc;
ionizers release positively charged ions that kill bacteria and algae.
Advantages
Silver deactivates harmful bacteria, viruses, protozoa and
fungi; copper kills algae.
Requires only periodic low doses of supplemental chlorine.
Disadvantages
Requires periodic replacement of parts .
Can cause staining.
Not allowed as a primary sanitation method for public pools in the
U.S.
and
Canada
,
without chlorine as a backup.
