Dangers of Dirty Water
The Bottom Line
There are many possible causes of contaminated water including physical, chemical, biological, and radiological agents. While the most common are contaminants that cause gastrointestinal toxicity, damage to other body systems can occur. The most vulnerable groups include infants and children, pregnant women, the elderly, and people who are immunocompromised.
What causes contaminated water?
Contaminants can end up in your tap water at the water’s source including reservoirs, lakes, rivers, or underground water, as well as by traveling through the plumbing. Common sources include manufacturing or fertilizers, pesticides, and other chemicals applied to land near water. It is also possible for water to be contaminated by agricultural operations, landfill leaks, sewer overflows, and poorly maintained septic systems. Animal waste is another common source of contamination.Common contaminants
There are many possible water contaminants. Sediment and organic material from soil erosion are physical contaminants. Arsenic or radon are found naturally in rocks and soil. Drugs (human and veterinary), metals (such as arsenic copper, lead, and mercury), nitrogen (such as ammonia and nitrates), pesticides, and salts are examples of chemical contaminants. Biological contaminants include bacteria (such as campylobacter, E. coli, legionella, salmonella, and shigella), parasites (such as giardia or cryptosporidium), protozoa, and viruses (such as enterovirus, hepatitis A, norovirus, and rotavirus). Cesium, radon, and uranium are examples of radiological contaminants.Health impacts of drinking contaminated water
The health impact of drinking contaminated water depends on the contaminant(s). Most common are contaminants that cause vomiting, diarrhea, and abdominal pain. Other adverse health effects include damage to kidneys, liver, skin, neurologic, reproductive, and other body systems. Chronic exposure to some pollutants may cause cancer. The most vulnerable groups include infants and children, pregnant women, and the elderly, as well as people who are immunocompromised.Did I drink contaminated water? Signs and symptoms
Since there are so many possible sources of water contamination, it is hard to pinpoint exact signs and symptoms. Recurring gastrointestinal illnesses may be associated with water contaminated with biological contaminants such as bacteria, viruses, protozoa, and parasites. If you are living in a home with old pipes and plumbing lines, exposure to heavy metals such as lead or copper is possible. Signs and symptoms of heavy metals vary depending on the metal, but often include gastrointestinal effects (including nausea, vomiting, diarrhea, abdominal pain), weakness, neurological symptoms, abnormal heartbeat, breathing difficulty, anemia, and kidney and/or liver damage. If you live near agricultural areas, your water may be contaminated with nitrates, nitrites, pesticides, and bacteria.
Some pesticides can get into your body both by swallowing and via the skin, so washing with contaminated water could also serve as a route of exposure. Pesticides can cause nausea, vomiting, diarrhea and abdominal cramps. Depending on the pesticide, other effects may include headache, dizziness, blurred vision, excessive sweating, salivation, runny nose, tearing eyes, increased urination, slow heart rate, wheezing, difficulty breathing, weakness, coma, and seizures. These are just a few examples of signs and symptoms associated with contaminated drinking water.
How to test your water quality
You can send a water sample to a certified laboratory for testing. If you have well water, your local health department may provide free testing. See here for a list of state certified laboratories.Drugs in the water supply
Drugs get into the water supply from human or animal waste. Drugs applied to the skin or that are eliminated through the skin can then be washed down the drain. Examples of drugs in drinking water include antibiotics, antidepressants, contraceptives, and steroids. With the exception of extremely toxic drugs and controlled substances that are likely to be abused, it is no longer recommended to flush drugs down the toilet. See FDA’s flush list for drug disposal. See here for more information on drugs in drinking water and prevention tips.Nitrate in drinking water
Inorganic nitrates such as potassium or ammonium nitrate used as fertilizers can contaminate drinking water. Sources of organic nitrates include seepage of human sewage and animal waste runoff. In the gastrointestinal tract, nitrates can be converted to nitrites, especially in infants.
Nitrates and nitrites cause vasodilation, resulting in low blood pressure. Nitrites can oxidize hemoglobin to methemoglobin. Methemoglobin impedes the ability of hemoglobin to carry and deliver oxygen. Infants are especially susceptible to nitrite-induced methemoglobinemia. Symptoms include nausea, headache, dizziness, shortness of breath, confusion, seizures, and coma. Skin, lips, and fingernails may look bluish-purple in color.
Is travelers’ diarrhea due to contaminated water?
Yes. Traveler’s diarrhea is caused by drinking water or eating foods in an area with poor public hygiene. It usually happens in the first two weeks of travel and is due to bacteria, viruses or protozoa. The most common organism is the bacterium E. coli, but this depends on location.I think my water is contaminated. What should I do?
If you think your water is contaminated, don’t drink it. Use bottled water until you can have your water tested. If you have questions/concerns about contaminated water, help from experts is available through the webPOISONCONTROL online tool and by phone at 1-800-222-1222. Poison Control’s expert guidance is always free, confidential, and available 24 hours a day.Clinical Toxicologist
Poisoned?
Call 1-800-222-1222 or
Prevention Tips
- Be sure the pipes and plumbing in your home are kept in good condition.
- If you have a septic system, properly maintain it.
- Test your well water annually for bacteria, nitrates, and pH levels.
- Consider using a water filtration system (but be aware it may also filter beneficial minerals such as magnesium and calcium).
- Do not drink water that is cloudy, has visible sediment, or has an oily film.
- Do not drink water that smells like rotten eggs, detergent or chlorine.
- Do not drink water that tastes salty, metallic or has a chemical taste.
- When hiking, purify water from lakes, streams and rivers by boiling it or using water purification tablets.
- When traveling in developing countries, drink and brush teeth with bottled water, avoid ice, avoid green salads and raw fruits and vegetables, unpasteurized milk, and foods and beverages purchased from street vendors. Open bottled water yourself and be sure the container has not been previously opened.
This Really Happened
A 5-month-old girl was well while being fed a powder formula diluted with bottled water. When her parents ran out of bottled water, they used tap water from the well to prepare her formula. She became irritable and fussy. When her parents saw that her skin was blue, especially around her nails and lips, they took her to the emergency department. In the emergency room she was lethargic, limp, short of breath, and cyanotic (bluish skin). When blood was drawn, it was noted to be ‘chocolate brown’ so methemoglobinemia was suspected. Laboratory tests showed a high methemoglobin level and metabolic acidosis. She responded to treatment with the antidote for methemoglobinemia (methylene blue), intravenous fluids and bicarbonate. The testing of the well water found elevated nitrate concentration; the diagnosis was methemoglobinemia due to nitrate-contaminated well-water.For More Information
References
Ma JY, Li MY, QiZZ, Fu M, Sun TF, Elsheikha HM, Cong W. Waterborne protozoan outbreaks: An update on the global, regional, and national prevalence from 2017 to 20202 and sources of contamination. Sci Total Environ. 2022;806(pt 2):150562. doi: 10.1016/j.scitotenv.2021.150562.
Omarova A, Tussupova K, Berndtsson R, Kalishev M, Sharapatova K. Protozoan parasites in drinking water: A system approach for improved water, sanitation and hygiene in developing countries. Int J Environ Res Public Health 2018;15(3):495. doi: 10.3390/ijerph15030495.
Prakash PR, Narayan A, Jain S, Wig N. Chronic arsenic poisoning: A sinister cause of peripheral neuropathy in a young couple. J Postgrad Med. 2024;70(2):105-108. doi: 10.4103/jpgm.jpgm_708_23.
Santos TM, Wendt A, Coll CCVN, Bohren, Barros AJD. E. coli contamination of drinking water sources in rural and urban settings: an analysis of 38 nationally representative household surveys (2014-2021). ;J Water Heath. 2023;21(12):1834-1846. doi: 10.2166/wh.2023.174.
Schaumburg F, Correa-Martinez CL, Niemann S, Kock R, Becker K. Aetiology of traveler’s diarrhea: A nested case-control study. Travel Medicine and Infection Disease. 2020:37:101696. doi.org/10.1016/j.tmaid.2020.101696.
Steffen R, Hill DR, DuPont HL. Traveler’s diarrhea: a clinical review. JAMA. 2015;313(1):71-80. doi: 10.1001/jama.2014.17006.
Warren-Vega WM, Campos-Rodriguez A, Zarate-Guzman A, Romero-Cano LA. A current review of water pollutants in American Continent: Trends and perspectives in detection, health risk, and treatment technologies. Ent J Environ Res Public Health. 2023;20(5):4499. doi: 10.3390/ijerph20054499.
Poisoned?
Call 1-800-222-1222 or
Prevention Tips
- Be sure the pipes and plumbing in your home are kept in good condition.
- If you have a septic system, properly maintain it.
- Test your well water annually for bacteria, nitrates, and pH levels.
- Consider using a water filtration system (but be aware it may also filter beneficial minerals such as magnesium and calcium).
- Do not drink water that is cloudy, has visible sediment, or has an oily film.
- Do not drink water that smells like rotten eggs, detergent or chlorine.
- Do not drink water that tastes salty, metallic or has a chemical taste.
- When hiking, purify water from lakes, streams and rivers by boiling it or using water purification tablets.
- When traveling in developing countries, drink and brush teeth with bottled water, avoid ice, avoid green salads and raw fruits and vegetables, unpasteurized milk, and foods and beverages purchased from street vendors. Open bottled water yourself and be sure the container has not been previously opened.