Tap Water Health Risks for the Immunocompromised

by Jay | Updated on July 26th, 2022

The E.P.A. (Environmental Protection Agency) sets standards for what are “safe” levels of contaminants commonly found in drinking water from municipal treatment plants. However, some people are more at risk than others from certain contaminants. The levels of contaminants found in the water should be taken into account, as even “trace” amounts can be harmful for some contaminants.

By law, all City Water Reports are required by the E.P.A. to include the following text in the report:

tap, black, faucet

“Some people may be more vulnerable to contaminants in drinking water than the general population. Immunocompromised persons such as persons with cancer undergoing chemotherapy, persons who have undergone organ transplants, people with HIV/AIDS or other immune system disorders, some elderly, and infants can be particularly at risk from infections.”

These people are urged to contact their health care providers

Who is Immunocompromised?

The mandatory text above does not give a complete list of persons who may have a greater risk from contaminants in drinking water. Aside from chemotherapy patients, organ transplant recipients and donors, and HIV/AIDS carriers, what are the “other immune system disorders” referring to?

In general terms, immune system disorders fall into two broad categories of primary immunodeficiency diseases: genetically determined and manifest at birth and acquired immunodeficiency diseases.

Even pregnant women should be aware of contaminants in tap water. Laura H. Kahn, in The Growing Number of Immunocompromised, states, “pregnant women also have varying levels of immunodeficiency–otherwise they would reject the fetus, a foreign body.” (Bulletin of the Atomic Scientists,

Fibromyalgia, diabetes, rheumatoid arthritis, COPD (chronic obstructive pulmonary disease), and chronic hepatic disease (cirrhosis and alcoholism), are just a few examples of chronic diseases considered immunodeficiencies.

People who take immunosuppressive drugs also fall into this category, such as people with Crohn’s Disease, rheumatoid arthritis, or inflammatory bowel disease. Even people taking antibiotics are temporarily immunocompromised.

Contaminants in Tap Water Pose Health Risks for Elderly and Infants

Both elderly and infants can be more susceptible to contaminants in water than the public. The elderly have lower levels of natural immunity, which can be exacerbated by poor nutrition. Infants also have low levels of natural immunity because their immune systems are immature.

Infants rarely have fully formed digestive tracts before 6 months and cannot process contaminants like nitrates or cryptosporidium in the water. Similarly, the elderly with poorly performing digestive tracts can experience digestive distress from high levels of nitrates or any cryptosporidium in water, even if ingested over a short period. Note that nitrates cannot be eliminated from boiling the water but are made more concentrated when boiled.

Studies show that fluoride has been attributed to arthritis and is especially more toxic to the immunocompromised. The elderly should be concerned about the levels of fluoride in tap water. “Early stages of [skeletal fluorosis]… may be misdiagnosed as rheumatoid arthritis or osteoarthritis,” according to the World Health Organization’s report, Fluoride and Human Health (pp. 238-249)

The blood-brain barrier is not fully developed in infants, allowing for the highly toxic fluoride to be harmful to infants. Newborn infants should not ingest high amounts of fluoride as it is a neurotoxin.

Cryptosporidium in Drinking Water

While municipal water providers are required by law to chlorinate the water, cysts and parasites like cryptosporidium and giardia are resistant to chlorine.

Infants, elderly, and immunodeficient persons are potentially at greater risk from cryptosporidiosis, a mild infection with flu-like symptoms, including severe diarrhea that was fatal to over 100 people in Milwaukee, Wisconsin, in 1993.

The fatalities were reported to be primarily immunocompromised, elderly, and infants and were often the result of dehydration.

The EPA regulates levels of contaminants in drinking water to establish an “acceptable health risk” for the general public, which means the average healthy adult will not get sick. The municipal water treatment plant does its best with limited tax dollars and rarely goes beyond testing or treating for contaminants required by law.

The EPA and the city provide tap water that meets minimal standards for purity. If you are concerned about contaminants in the water that exceed legal limits or are immunocompromised and concerned about the water quality, consider investing in a reverse osmosis water filtration system that will remove nitrates, cryptosporidium and almost all other contaminants in drinking and cooking water.

Sources and Resources

“The Growing Number of Immunocompromised” by Laura H. Kahn, Bulletin of the Atomic Scientists,

Environmental Protection Agengcy (EPA)

Center for Disease Control (CDC)

Nursing Center.com provides an excellent and thorough explanation of the immune system as pertains to the immunodeficient patient.


Jay is a health and wellness enthusiast with expertise in water quality and nutrition. As a knowledgeable advocate for holistic well-being, Jay successfully manages Type 2 Diabetes through informed lifestyle choices. Committed to sharing reliable and authoritative insights, Jay combines firsthand experience with a passion for enhancing health."