: Microcobes in our Water

Joan Rose, Ph.D., is an Associate Professor in the Department of Marine Sciences, College of
Public Health, University of South Florida. Her area of expertise is water pollution microbiology She has been involved in the investigation of recent waterborne outbreaks of Cryptosporidium, and she is well known for her participation in the NBC TV program "Dateline" which focused on the Cryptosporidium outbreak in Milwaukee. Dr. Rose has served on the National Academy of Sciences committee and the Science Advisory Board for the EPA and was recently invited to join the National Drinking Water Council. The following is a synopsis of her presentation at a 1995 Conference in Las Vegas.

In the U.S. we are facing degradation of our waterways by pollutants and microbial contaminants resulting in an average of one million cases of waterborne disease per year. Microbial contaminants, such as Giardia, Cryptosporidium, and the new Cyclospora, are causing major outbreaks across the nation.

In the 1960's Giardia became a prevalent contaminant of health concern that prompted the enactment of the Surface Water Treatment Rule that stated that all surface water that may potentially be used for drinking water must be filtered. Unfortunately, problems with Giardia, viruses, newer protozoans (like Cyclospora), and, especially, Cryptosporidium are still occurring.

Chlorination has little effect on cysts and protozoans like Cryptosporidium. We are also finding that merely filtering surface water isn't solving the problem since most microbial outbreaks of this sort are occurring in ground water sources (of all the waterborne outbreaks between 1991-92, 77% occurred in wells). Even pristine water sources (which are closed to human activity) are not safe from microbial contamination since sources of microbial contaminants are not only human waste products, but also animal feces.

Giardia can be killed by long contact with chlorine, but Crypto is much more resistant. Filtration is the only effective way to get Crypto out of the water. Often, unfortunately, "rapid filtration" at the public utilities water treatment plants doesn't do the job, and Crypto makes it through to the public's tap water.

Recently, a new cyst, Cyclospora, has made its presence known. Like Crypto, it produces intestinal disorders and is resistant to disinfection. Unlike Crypto, Cyclospora oocysts must be mature before they are infectious (so, if the body clears the cysts before maturation, there will be no infection). It is also larger in size than Crypto and is, therefore, easier to filter out of the water.

Although most of the intestinal disorders caused by microbial infection affect a large segment of the population only like a stomach flu or traveler's diarrhea, over 5 million Americans (the immunocompromised, the aged, infants, and pregnant women) are at a much greater risk (possibly even of death). Emerging patterns of rainfall, sewage overflows, and animal excrement are leading experts to believe that microbial outbreaks are going to continue and probably worsen.

Filtration has become the focus for control of these microorganisms. Disinfection had always been the major barrier for control, but we are finding microorganisms that are resistant to disinfection. Filtration has got to be the focus here.

Health Effects of Giardia and Cryptosporidium in Drinking Water

David Ozonoff, Chairman, Environmental Health Department, Boston University: "I think the problem today is that turning on your tap is an act of faith, and I'm not sure that that act of faith is particularly well- placed." If you drink from the tap, there are several recent studies you should know about because they may change the way you think about your water.

U.S. Health Officials estimate 900,000 people each year become ill, and possibly 900 die, from waterborne disease. The General Accounting Office estimates 66% of Safe Drinking Water Act violations aren’t reported.

U.S. Warns of Parasite In Tap Water, Washington Post, June 16, 1995. Between 60,000 and 1.5 million Americans a year fall ill form exposure to waterborne cryptosporidium parasites.

Cryptosporidium, is common in water supplies and can infect people at a very low levels, says a study in today’s New England Journal of Medicine, March 30, 1995.

Microscopic cysts ( Giardia and/or Cryptosporidium ) have been found in 97% of surface water supplies and 39% of drinking water supplies in the U.S.. More than 900,000 people become ill each year form waterborne parasites like Giardia and Crypto. Waterborne illness caused by cysts can be fatal for those who have compromised immune systems. The 50,000 Americans who are immunocompromised have been advised to either boil all of their water or invest in a filter that is certified by NSF International for cyst removal.

Cryptosporidium is a round oocyst approximately 3-4 microns in diameter, but can fold to an even smaller size. It is resistant to chlorine disinfection, causes intestinal disorders in healthy people, and can result in death for immunosuppressed people. Notable outbreaks occurred in Milwaukee, WI in 1993, and Las Vegas, NV, in 1994. Giardia is a round cyst approximately 5-6 microns in diameter. It can be killed only by long contact with chlorine disinfection, and causes intestinal disorders in healthy people. Recent outbreaks have occurred in Amsterdam, NY, Oregon, Georgia, and in Golden, CO.

: Microorganisms in our Tap-Water

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 1960s, 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 90,000 people a year are mad sick by such microbial contamination of tap water.

: Surface-Water: Treatment-Rule

The Surface Water Treatment Rule states that all surface water may potentially be used for drinking water must be filtered. Unfortunately, problems with Cryptosporidium , Giardia, and newer protozoa (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).

Many cities have systems dating from before World War II, and in some rural areas the water systems are reminiscent of the Third World. More and more people are wondering what to do about cyrptosporidium and other cysts in their water supplies. Thousands of water systems don't test their water as the law requires. When water companies do test the water and find serious pollution problems, they often don't report them to state officials, again, as the law requires. In addition, the GAO found that state officials often don't report violations to the EPA.

: Illness with a Cyst-Infection

Healthy individuals infected by these parasites experience a cholera-like illness: watery diarrhea, headache, abdominal cramps, nausea, vomiting, and low-grade fever. For the immuno-compromised, however, the results of infection are often grave: the parasites can severely damage the liver and respiratory tract, as well as the gallbladder and pancreas. Even worse, there is a 40-50% mortality rate for the immuncompromised 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.

: Solutions

Under conditions of average temperature, humidity, and activity, the human body loses and, therefore, must replace about 2.3 liters of water each day. Two-thirds of this consumption is in the form of water or some other beverage. Concerns about the health risks or taste of drinking water may induce those who consume tap water to shift to bottled water, or other beverages. These beverages may include sweetened soft drinks and alcoholic beverages, which can pose health risks greater than those associated with drinking water.

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 NSF International 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.

New FDA specifications, which are nearly identical to the Environmental Protection Agency's requirements for municipal water, are designed to ensure that bottled water is as safe as that from the tap. That the regulations go no further may come as a surprise to countless consumers who have paid dearly for store-bought water. In addition, the production and disposal of containers for alternative beverages, including bottled water, may lead to the release of carcinogens.

It just may be the case that point-of-use filtration is the only viable alternative to rid the nations tap water of these dangerous contaminants.