Who
first used
chlorine in a swimming pool?
What
is the
history of pool chlorination?
When
was chlorine
first used to sterilize swimming pools?
Why do we use chlorine?
History
of Chlorine as a Swimming Pool Sanitizer.
"To
most
people swimming pools conjure summer afternoons dedicated to carefree
indulgences like lime daiquiris and a satisfying bad novel. Pools are pleasure ponds and
symbols of suburban arcadia." (S. Garbarino, The Pool in Film: Deep and
Lovely And Full of Sharks, New York Times, 2003, July 27, ST1)
A
Complete
History of Chlorine Use Has Been Submitted to the Bulletin
for the History
Of Chemistry,
a
publication of the American Chemical Society.
The
purpose of
this page is to provide a quick answer to the question, who invented
chlorine
for swimming pools?
It is
commonly
believed that the ancient Romans were the inventors of the swimming
pool or
public baths, they were actually latecomers to the idea.
For much of western history, bathing was
performed only infrequently and very few people even knew how to swim. The nineteenth century British enjoyed
public baths in India and Japan and they brought the modern swimming
pool back
home to England.
The
first public
swimming pool to open in the United States was in the town of
Brookline,
Massachusetts, in 1887.
Prior
to the
introduction of sterilization technologies most swimming pools were
filtered to
keep them somewhat clean and the water was changed frequently.
Chemical
producers began making Bleaching Powder in the 1890s when cheap
electricity from central generating stations became available.
Bleaching
powder
is calcium oxychloride (CaOCl2) although it is often erroneously called
calcium
hypochlorite [Ca(OCl)2 * 4H2O].
Bleaching powder was made by reacting chlorine gas with lime.
The
chlorine was
supplied as a by-product of the electrolytic production of sodium
hydroxide. Passing an electric
current through a concentrated solution of sodium chloride liberates
chlorine
and hydrogen as gasses and leaves behind concentrated sodium hydroxide. Sodium hydroxide was commonly known as
caustic soda. It was, and still
is, used in a great variety of industrial processes including soap and
glass
manufacture.
Credit
for the
first use of chlorine to disinfect potable water goes to the British
scientist Sims
Woodhead who used "bleach solution" as a to sterilizing agent during
a typhoid outbreak in Maidstone, Kent.
The
first regular
use of chlorine for potable water treatment was at Jersey Citys Boonton
Reservoir, in Boonton, New Jersey in 1908.
By
the early
1900's waterworks engineers had mastered the use of chlorine and
filtration. Educators and health
professionals appreciated the value of swimming for physical fitness. All of the elements of the modern
swimming pool were in place.
As
near as the author
can determine, the first attempt to sterilize a pool in the United
States using
chlorine was at Brown University in 1910.
The 70,000-gallon Colgate Hoyt Pool was chlorinated by graduate
student John
Wymond Miller Bunker.
(W.
Bunker, The
Hygenie of the Swimming Pool, American Journal of Public Hygiene, 1910 (20:4), 810-812.)
Bunker
applied
hyperchlorite of lime (sic) to 2 liters of pool water at a
concentration of 1
ppm.
According
to the New
York Times, the
pool
remained sterile for four days.
Shortly
after the
Brown University experiment, the Lancet was publishing papers related
to the bacterial
contamination of swimming baths and means to sterilize them, including
chlorination.
By
the middle of
the twentieth century compounds consisting of chlorine with cyanuric
acid
became available for swimming pool use.
Like earlier forms of chlorine sterilizers, these materials
function as
a source of hypochlorous acid, which is the active sanitizing agent.
When
used
correctly, the combination of dichloroisocyanurates and cyanuric acid
stabilizers provides long lasting chlorine, good solubility, ease of
application, and will not affect the pH of the water.
Today
the typical
residential pool owner uses a combination of chlorine-containing
isocyanurates pressed
into slowly dissolving tablets for steady, long term chlorination, and
calcium
hypochlorides for periodic "shock treatments."
The
United States
Public Health Service first published a model ordinance governing the
construction, sterilization, and use of public pools in 1961.
The
first
fissures in the summer love affair of chlorine and swimming came in
1974 when
chemists first discovered that halogens could react with organic
material in
drinking water to create chloroform and other trihalomethanes.
Should
the
average swimmer be concerned about chloroform exposure?
The
EPA has
studied the subject and published a number of documents.
The interested reader should consult
these.
This
Information
Posted by:
Kevin Olsen
Instrumentation Specialist
Chemistry and Biochemistry Support Staff
Room 359 Richardson Hall
Montclair State University
Normal Ave
Montclair, NJ, 07043
973-655-4076
973-655-7772 (Fax)
OlsenK@Mail.Montclair.Edu