Cysts

Over 45 million Americans drink water from treatment plants that have found the cyst Cryptosporidium, the protozoan found in tap water that infected over 400,000 people and killed over 100 in Milwaukee. Giardia, a cyst that has been recognized since the 1960's, has been estimated to cause 5 to 10 waterborne outbreaks annually, an average of 4000 hospital admissions per year, and an average of 6 million dollars in hospital treatment costs annually. Natural Resources Defense Council (NRDC) attorney Erik Olson cited a report by the Centers for Disease Control (CDC) estimating that 900,000 people a year are made sick by such microbial contamination of tap water. More and more people are wondering what to do about cryptosporidium and other cysts in their water supplies.

The Surface Water Treatment Rule states that all surface water that may potentially be used for drinking water must be filtered. Unfortunately, problems with Cryptosporidium, Giardia, and newer protozoans (like Cyclospora, which is larger in size than Crypto, thus more easily filtered) are still occurring, predominantly in ground water sources (which do not fall under the Surface Water Treatment Rule). Also, because Cryptosporidium is pliable, it can fold down to one micron in size, thus slipping through most public utilities filtration systems. The only water treatment devices that can effectively filter Crypto are those certified for submicron filtration (less than one micron).

Healthy individuals infected by these parasites experience a cholera-like illness: watery diarrhea, headache, abdominal cramps, nausea, vomiting, and low-grade fever. For the immunocompromised, however, the results of infection are much more dire: the parasites can severely damage the liver and respiratory tract, as well as the gall-bladder and pancreas. Even worse, there is a 40 - 50% mortality rate for the immunocompromised who are infected with Cryptosporidium. Those at risk include cancer patients undergoing chemotherapy, infants, the elderly, kidney dialysis patients, recent transplant recipients, AIDS patients, and others with suppressed immune systems.

To the over 5 million Americans at risk, the CDC and the Environmental Protection Agency have issued a guidance to either boil all of their tap water, invest in certain bottled water, or purchase a filter that is certified by UL to remove cysts. As many can attest, boiling all of the tap water can be unduly burdensome. The bottled water alternative also presents problems. Carol Browner, head of the EPA, warned that bottled water is not tested for microbial contaminants like Cryptosporidium, so consumers really don't know what they're getting with bottled water. It just may be the case that point-of-use filtration is the only viable alternative to rid the nation's tap water of these dangerous organisms. Only those filters that are certified under ANSI/NSF Standard 53 for cyst removal are recommended by the CDC and the EPA.