How to Remove Giardia Cysts Contamination in Drinking Water
GIARDIA in DRINKING WATER - CONTENTS: Treatment and sterilization options for drinking water containing giardia cysts. How to treat, purify, or sterilize drinking water in an emergency.How to use bleach, boiling, chlorine, distillation, filters, hydrogen peroxide, iodine tablets, or iodine liquid to purify drinking water. How to get rid of chlorine odors or other chemical odors in emergency drinking water supplies
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Giardia contamination in water: this article explains Giardia cyst contamination in drinking water and we review alternative treatment, sterilization, or giardia removal methods used to make drinking water safe from giardia contamination.
How to Treat or Purify Giardia-contaminated Water to Sanitize it For Drinking
Chemical contaminants: If your water supply has become contaminated by pesticides, heavy metals, or other chemicals, disinfecting the water will not correct those unsafe conditions.
Protozoan contaminants: Chlorine and iodine are good disinfectants against bacterial contamination (probably among the most common water contaminants) but studies cited in this article have shown that these are not effective against certain contaminants in water such as toxic chemicals, Cryptosporidia (Cryptosporidium parvum) , and Giardia.
Also see REFERENCES.
Filtration and boiling are additional steps that can address these microorganisms. Activated charcoal can remove some chemical contaminants but has limited life and capacity.
This article series outlines methods to purify or sanitize drinking water in an emergency following a disaster such as an earthquake, flood, or hurricane. Some of the water treatment or water purification methods discussed are also used for regular non-emergency water sterilization as well.
Advice for Dealing with Giardia cysts in Drinking Water
InspectAPedia.com reader Sharon Ross is a New York City resident, a Riverkeeper member and a MENSA member, who for health reasons has collected references and treatment information about dealing with Giardia cyst contamination in drinking water. This article is in draft form and is incomplete. Contact Us with corrections or suggestions.
Giardia cysts also survives the amounts of chlorine in municipal water treatment. Dr. Herman Bueno, a Parasitologist I conferred with
reported in 1994 that people with AIDS were dying of Giardia in hospitals because of their weakened immune systems. We would not recommend that anyone with a compromised immune system eat raw vegetables without sufficient sterilization to kill parasite cysts.
Ceramic Filters for Giardia cyst & Cryptosporidium Removal from Drinking Water
There are ceramic giardia and cryptosporidium filters that can be used to filter tap water so that cysts will not be ingested by drinking it. The company that I have bought my ceramic filter from is Duff company, though there are other companies that also carry them. The ceramic filters are "absolute" and if used properly, remove the cysts 100 percent.
Well water, or even municipal water when it delivered inside of some buildings, contains high levels of sediment that causes water filters to clog quickly. Thus water filters may need cleaning as often as every few days, making filtration to remove giardia a labor intensive solution. But it beats being exposed to cysts
which may be present in some drinking water supplies.
Eventually ceramic water filters wear down from the constant scrubbing and they have to be replaced. Even with the work involved, we recommend them for anyone with a compromised immune system.
Charcoal Water Filters for Giardia cyst & Cryptosporidium Removal from Drinking Water
Granulated charcoal filters do not work.
Environmental activist, Robert F Kennedy Jr. has been aware of Giardia contamination of our water and we think that he was trying to get a filtration system that would remove cysts built for NYC. The problem was the cost - by some estimates over a billion dollars.
Whole House Filtration Systems for Giardia cyst & Cryptosporidium Removal from Drinking Water
There are now both point of use reverse osmois systems (photo at left) and whole house filters or RO systems that remove parasite cysts. A sample proposal for a whole house reverse osmosis (RO) water treatment system is provided at Example of an Equipment Design for Water Filtration for Giardia. A reverse osmosis whole house filter system including a large storage tank can be installed if you own your own home and have a place to put it.
Also available is a filter attachment to remove nitrates as well, since nitrates can be a problem in some areas. I am sending you is an attachment with a link. Sato Iwasa of Pure Water Express was very helpful and knowledgeable in discussing whole house water treatment options.
OPINION: Our beaches are no longer safe for the immune compromised and maybe not for others as well. Billions of tons of raw sewage are being dumped into Long Island Sound because we do not have the sewage treatment plants to handle it. This can be confirmed by another New York environmental organization, "Riverkeeper".
That means that waste from third world immigrants who are carriers of parasites from India, the middle east, China, and Latin America and other countries where parasites are endemic is being carried by the currents to the ocean beaches that New Yorkers swim in. According to Dr. Bueno, cysts take at least three days to die in ocean water so they can be still viable and be ingested.
Examples of U.S. Sources of Giardia Infection
You do not have to travel to a foreign country to be exposed to Giardia cysts, though it has been our experience that many physicians still believe that you do, and if you complain of parasite related symptoms they still ask you if you have left the country.
Giardia Contamination Around New York City
In New York there are huge storm
drain runoff pipes that run into Little Neck Bay. Some of them are near Alley Pond Environmental center and you can speak to the director of the center about them. I had taken a wrong turn on a trail in Alley Pond park leading from the center when encountered a terrible stink and I came one of "storm" drains which are storm drains no longer and there is a constant flow of sewage from them. There was a hoard of seagulls circling overhead and the filth was pouring into the waters leading to the sound. When we (Ross) asked the director about why this was happening, since it was a sunny dry day with no rain in sight, he told me that the storm drains are in operation constantly because we do not have the facilities to handle all of the raw sewage.
On the opposite side of the storm drains running into Little Neck Bay are Westchester beaches, though few doctors would make the connection if someone complains of exhaustion weakness, diarrhea, MS like symptoms and abdominal pain.
Dr. Tennenbaum, an infectious disease specialist reported that they now treat empirically for Giardia if the person has been in endemic areas in our country i.e.: vacationing in Maine, and is exhibiting symptoms. because Giardia is so difficult to find. We do not know if New York City is considered an endemic area for Giardia.
Eating out in some restaurants can also cause problems. Giardia is endemic to the USA and can be carried and spread from anyone born here who has been infected. Further, restaurant workers who have lived-in countries where parasites like entameoba histolytica are common may be a potential source of parasites.
Some people who suffer from a compromised immune system no longer eat out in restaurants.
Safe foods? According to Dr. Amin, parasite cysts cannot withstand the freeze/thaw cycle, so am safe with ice cream (I
am not considering bacteria that can withstand freezing) and food taken out from a restaurant that is frozen, thawed and then re-heated.
Ross recommends that anyone wash their hands thoroughly when they come home and turn public faucets on and off with clean paper towels.
Difficulty in Diagnosing & Treating Giardia Infection
When a person first becomes
infected with Giardia, stress and irritable bowel may be suggested by more than one physician.
Parasite cysts are often difficult to spot under the microscope and tests for them can manifest negative results when a person is really infected. Dr. Bueno reported that the US army tests GI's 8 times if they complain of parasite type symptoms and the results are negative. Dr. Amin also said that two stool samples might not be sufficient to determine if a person is infected.
Use of UV light, Vinegar, or Chlorine for Giardia cysts ?
Reader Opinion about vinegar's effectiveness on Giardia
As for vinegar as a method of killing giardia cysts, it is highly acidic and it breaks down the walls of
the giardia cysts, if it is used full strength. Dr. Omar Amin, of
"Parasitology Center " in Tempe, Az confirmed this. [WARNING: authoritative sources confirming the safety of this approach have not been obtained.]
Here is a representative reader comment:
"I have battled an immune disorder and I had been very ill with
intractable Giardia because of my condition. I do not eat raw
produce now unless I sterilize it. Right now, I use distilled white
I submerge vegetables in pure vinegar for 25 minutes but
more porous vegetables have a vinegar taste when I am done.
ceramic giardia filters on my tap water now and I was thinking that if
I could use a peroxide solution, and then rinse off the peroxide in
fresh, giardia free water, I would not have to deal with a vinegar
UV doesn't kill cysts, according to Dr. Amin and I have seen websites that
advertise it to kill giardia which is very misleading. it will kill Giardia
trophozoites but the real concern for drinking water is the cysts, since it
is the cysts from stool that appear there.
Really? you might want to take a look at "A-class" vs "B-class" UV treatment systems as their ability to deactivate parasitic cysts varies. - Ed. ]
Chlorine does kill cysts in high enough amounts, the amount that one would
find in a swimming pool, amounts not suitable for drinking and I was told by
another parasitologist that I have conferred with, that
the cysts would take about 20 minutes to die in a chlorinated
A-class UV light treatment systems combined with chlorine treatment has been used for treatment of Giardia infected water. But
Watch out: failure to keep the UV system clean, to match the light intensity and size and treatment time to the flow rate of water through the system, or other snafus can prevent UV from working effectively even where it is considered most-effective on non-pathogenic bacteria in the water supply. Ed.
Example of an Equipment Design for Water Filtration for Giardia, Equipment Costs
Pre-filter Water Filter for Sediment Removal
Optional: install a plastic sediment filter 1-1/2" model to remove sediment, $289 includes shipping, ref: www.purewaterexpress.com/wholehouse.htm#3a removes dirt before the water supply enters the reverse osmosis component, providing insurance protection of the RO filter against water main work upstream (or a private well water source containing sediment) sending massive debris into the water treastment system.
Reverse Osmosis RO Treatment Unit Cost
Compact II-2: special high flow membrane, daily production 250 gallons minimum, $1,548 plus shipping from Perris, CA, reference: www.purewaterexpress.com/wholehouse.htm#9.
Other reverse osmosis, filter, ceramic filter and water treatment products are listed at the end of this article.
Post Reverse-Osmosis RO Water Treatment Processing Equipment Options
165 gallon storage tank, float switch,1 HP re-pressurization pump, low pressure cutoff safety switch, $2,122 plus shipping from MN
1-1/2 cubic foot reverse flow acid neutralizer, $342, 1 cubic foot calcite $60, plus shipping from MN, restores pH of RO water close to neutral, ref: www.purewaterexpress.com/wholehouse.htm#7
Post RO polishing carbon +UV 20” Big Blue $1,049 includes shipping, ref: www.purewaterexpress.com/wholehouse.htm#5 Carbon makes delicious tasting water, UV protects against potential bacterial growth over time in the storage tank
Research on Giardia & Cryptosporidium Parasitic Cysts as Contaminants in Drinking Water
Atherton, F., C. P. S. Newman, and D. P. Casemore. "An outbreak of waterborne cryptosporidiosis associated with a public water supply in the UK." Epidemiology and Infection 115, no. 01 (1995): 123-131.
Betancourt, Walter Q., and Joan B. Rose. "Drinking water treatment processes for removal of< i> Cryptosporidium</i> and< i> Giardia</i>." Veterinary parasitology 126, no. 1 (2004): 219-234.
Flanagan, P. A. "Giardia--diagnosis, clinical course and epidemiology. A review." Epidemiology and Infection 109, no. 1 (1992): 1.
Fraser, G. Graham, and Kenneth R. Cooke. "Endemic giardiasis and municipal water supply." American journal of public health 81, no. 6 (1991): 760-762.
Hashimoto, Atsushi, Shoichi Kunikane, and Tsuyoshi Hirata. "Prevalence of Cryptosporidium oocysts and Giardia ysts in the drinking water supply in Japan." Water Research 36, no. 3 (2002): 519-526.
Hayes, Edward B., Thomas D. Matte, Thomas R. O'Brien, Thomas W. McKinley, Gary S. Logsdon, Joan B. Rose, Beth LP Ungar et al. "Large community outbreak of cryptosporidiosis due to contamination of a filtered public water supply." New England Journal of Medicine 320, no. 21 (1989): 1372-1376.
Jephcott, A. E., N. T. Begg, and I. A. Baker. "Outbreak of giardiasis associated with mains water in the United Kingdom." The Lancet 327, no. 8483 (1986): 730-732.
Kent, George P., JOEL R. Greenspan, Joy L. Herndon, Lynne M. Mofenson, J. A. Harris, Thomas R. Eng, and Hetty A. Waskin. "Epidemic giardiasis caused by a contaminated public water supply." American journal of public health 78, no. 2 (1988): 139-143.
LeChevallier, MARK W., William D. Norton, and Ramon G. Lee. "Giardia and Cryptosporidium spp. in filtered drinking water supplies." Applied and Environmental Microbiology 57, no. 9 (1991): 2617-2621.
LeChevallier, Mark W., William D. Norton, and Ramon G. Lee. "Occurrence of Giardia and Cryptosporidium spp. in surface water supplies." Applied and Environmental Microbiology 57, no. 9 (1991): 2610-2616.
Levine, W. C., W. T. Stephenson, and G. F. Craun. "Waterborne disease outbreaks, 1986-1988." MMWR. CDC surveillance summaries: morbidity and mortality weekly report. CDC Surveillance Summaries/Centers for Disease Control 39, no. 1 (1990): 1-13.
Mac Kenzie, William R., Neil J. Hoxie, Mary E. Proctor, M. Stephen Gradus, Kathleen A. Blair, Dan E. Peterson, James J. Kazmierczak et al. "A massive outbreak in Milwaukee of Cryptosporidium infection transmitted through the public water supply." New England journal of medicine 331, no. 3 (1994): 161-167.
Rose, Joan B., Charles P. Gerba, and Walter Jakubowski. "Survey of potable water supplies for Cryptosporidium and Giardia." Environmental Science & Technology 25, no. 8 (1991): 1393-1400.
Rose, Joan B., Charles N. Haas, and Stig Regli. "Risk assessment and control of waterborne giardiasis." American journal of public health 81, no. 6 (1991): 709-713.
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Questions & answers on the effectiveness of various water treatment & filtering methods on giardia cyst contamination.
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Dr. Omar Amin, of the Tempe AZ
Parasitology Center, corresponded with Sharon Ross (citation below), one of our readers asking about peroxide: "You can use hydrogen peroxide if you want to
but we do not have a track record of percentage dilution".
Dr. Amin has done research for the US military and for the CDC.
Aquamira™ chlorine dioxide water purification kits - see www.aquamira.com/
"Aquamira Water Treatment Drops were introduced to the Outdoor market in 1999 and have been a favorite of top outdoor guides and instructors ever since. Whether you are camping, traveling in a foreign country or faced with a disaster, our goal is to provide you with safe, pure and good tasting drinking water. Our complete line of water treatment products include leading edge purification and filtration technologies developed and tested in the lab and proven in the field. We offer systems and products that will provide water for a single individual or a village and almost anything in between."
"Bacteria in Drinking Water" - "Chlorine," Karen Mancl, water quality specialist, Agricultural Engineering, Ohio State University Extension. Mancl explains factors affecting the effectiveness of chlorine in water as a means to destroy bacteria and other microorganisms. OSU reports as follows:
Chlorine kills bacteria, including disease-causing organisms and the nuisance organism, iron bacteria. However, low levels of chlorine, normally used to disinfect water, are not an effective treatment for giardia cysts. A chlorine level of over 10 mg/1 must be maintained for at least 30 minutes to kill giardia cysts. -- http://ohioline.osu.edu/b795/index.html is the front page of this bulletin.
Crystal Clear Supply provides portable ceramic water filter purifiers and portable reverse osmosis water treatment equipment - see http://www.crystalclearsupply.com/category_s/7.htm
"Do Iodine Water Purification Tablets Provide an Effective Barrier against Cryptosporidium parvum?", Starke, Jeffrey A., Bowman, Dwight D., Labare, Michael, Fogarty, Elizabeth A., and others, Military Medicine, 25 October 2001 [possibly a later version of this article appeared in 2005 -DF]www.amsus.org/military medicine/milmed.htm
"Drinking Water Safety in Emergencies", University of Minnesota extension, extension.umn.edu/info-u/nutrition/BJ646.html
Duff Company provides ceramic filters: 610 275-4453.
EPA: www.epa.gov/ogwdw/mdbp/pdf/alter/chapt_2.pdf provides an article on use of disinfectants for water treatment
FDA Warning about drinking hydrogen peroxide: www.truthorfiction.com/rumors/h/hydrogen-peroxide.htm This article cites a 2003 entry in Journal
of Food and Science on using Hy.Perox to sterilize vegetables, referring to E.coli - NOT to Giardia.
GIARDIA in DRINKING WATER exposure limits for drinking water: see www.mass.gov/dep/water/drinking/standards/giardia.htm is the current regulatory exposure limit (your minimum target for
Hankey and Brown home inspectors, Eden Prairie, MN, technical review by Roger Hankey, prior chairman, Standards Committee, American Society of Home Inspectors - ASHI. 952 829-0044 - hankeyandbrown.com 11/06
Handbook of Disinfectants and Antiseptics, Joseph M. Ascenzi (Editor), CRC, 1995, ISBN-10: 0824795245 ISBN-13: 978-0824795245 "The evaluation of chemical germicides predates the golden age of microbiology..." -
This well-focused, up-to-date reference details the current medical uses of antiseptics and disinfectants -- particularly in the control of hospital-acquired infections -- presenting methods for evaluating products to obtain regulatory approval and examining chemical, physical, and microbiological properties as well as the toxicology of the most widely used commercial chemicals.
Potable Aqua® emergency drinking water germicidal tablets are produced by the Wisconsin Pharmacal Co., Jackson WI 53037. 800-558-6614 pharmacalway.com
Principles and Practice of Disinfection, Preservation and Sterilization (Hardcover)
by A. D. Russell (Editor), W. B. Hugo (Editor), G. A. J. Ayliffe (Editor), Blackwell Science, 2004. ISBN-10: 1405101997, ISBN-13: 978-1405101998.
"This superb book is the best of its kind available and one that will undoubtedly be useful, if not essential, to workers in a variety of industries. Thirty-one distinguished specialists deal comprehensively with the subject matter indicated by the title ... The book is produced with care, is very readable with useful selected references at the end of each chapter and an excellent index. It is an essential source book for everyone interested in this field. For pharmacy undergraduates, it will complement the excellent text on pharmaceutical microbiology by two of the present editors."
The Pharmaceutical Journal: "This is an excellent book. It deals comprehensively and authoritatively with its subject with contributions from 31 distinguished specialists. There is a great deal to interest all those involved in hospital infection ... This book is exceptionally well laid out. There are well chosen references for each chapter and an excellent index. It is highly recommended." The Journal of Hospital Infection.: "The editors and authors must be congratulated for this excellent treatise on nonantibiotic antimicrobial measures in hospitals and industry ... The publication is highly recommended to hospital and research personnel, especially to clinical microbiologists, infection-control and environmental-safety specialists, pharmacists, and dieticians."
New England Journal of Medicine: City Hospital, Birmingham, UK. Covers the many methods of the elimination or prevention of microbial growth. Provides an historical overview, descriptions of the types of antimicrobial agents, factors affecting efficacy, evaluation methods, and types of resistance. Features sterilization methods, and more. Previous edition: c1999. DNLM: Sterilization--methods.
Pure Water Express, Sato Iwasa, has U.S. facilities located in Harvard, MA 01451, 888-928-3794 email@example.com or website: www.purewaterexpress.com/ There are "Big Blue" filters that pure water express carries that aren't ceramic but that also effective in removing cysts.
Riverkeeper, is located at 828 South Broadway, Tarrytown, NY 10591 - 800-21-RIVER - firstname.lastname@example.org
To Report a Polluter: 800-21-RIVER ext 242 - Email: email@example.com
Riverkeeper Press Liaison: Andrea Kott, 914-478-4501 ext. 239 - Email: firstname.lastname@example.org riverkeeper.org.
Riverkeeper’s mission is to protect the ecological integrity of the Hudson River and its tributaries, and to safeguard the drinking water supply of New York City and the lower Hudson Valley. For more than 40 years Riverkeeper has been New York’s #1 clean water advocate. We have helped to establish globally recognized standards for waterway and watershed protection and serve as the model and mentor for the growing Waterkeeper movement that includes more than more than 180 Keeper programs across the country and around the globe.
Sharon Ross is a New York City resident, a Riverkeeper member and a MENSA member, who for health reasons has collected references and treatment information about dealing with Giardia cyst contamination in drinking water.
Katadyn™, a Swiss corporation provides water filters, desalinization equipment, and their Micropur chlorine dioxide water purification - see www.katadyn.com/usen/
"Katadyn offers a wide variety of water filtration and purification products suitable for any need. This allows outdoor enthusiasts and travelers to take along products for making their own drinking water when preparing their trips."
Patent: This patent application for UV light sterilization www.patentstorm.us/patents/6565803.html Lists good references on water
purification for Giardia et als
Arlene Puentes, a licensed home inspector, educator, and building failures researcher in Kingston, NY. 11/29/06
When Technology Fails, Matthew Stein, Chelsea Green Publisher, 2008,493 pages. ISBN-10: 1933392452 ISBN-13: 978-1933392455, "... how to find and sterilize water in the face of utility failure, as well as practical information for dealing with water-quality issues even when the public tap water is still flowing". Mr. Stein's website is www.whentechfails.com/
Wikipedia on history of use of hydrogen peroxide: Information on Hydrogen peroxide as a sterilant is in Wikipedia at en.wikipedia.org/wiki/Sterilization_(microbiology) HO2 has been
used for a long time, including by vaporization for sterilizing freeze dryers.
Wilderness Medical Society has advice about boiling water for consumption
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