Water Contaminants & Health Effects

Below is a list of water contaminants and their possible health effects. Click on contaminant link names for more detailed information about a specific contaminant.

For more information on common contaminants or contaminants removed by the reverse osmosis process, see these guides:

Common Drinking Water Contaminants & Removal Contamninants Removed by Reverse Osmosis

Water Contaminants and Health Effects
Contaminant Health Effects
Arsenic Malignant tumors of skin and lungs, cramps, spasms, effects to nervous system
Asbestos Malignant lung cancer, mesothelioma, asbestosis
Bacteria Dependant on type of bacteria
Barium Prolonged stimulant action on muscles, nerve block
Benzene Associated with cancer, leukemia, anemia
Cadmium Bronchitis, anemia, gastrointestinal upsets, cancer in rats
Carbon tetrachloride Central nervous system depression, gastrointestinal effects, liver and kidney damage, coma, death
Chlordane Carcinogen, liver and kidney damage
Chlorobenzene Irritation to respiratory system, central nervous system depression
Chloramines No observed health effects from drinking water with chloramine levels of less than 50 mg/L in drinking water
Chlorine Irritation to respiratory system, eyes and skin, corrosive tissue damage of the gastrointestinal tract
Chloroform Possible liver, kidney and heart effects; carcinogenic in at least one animal species
Chromium Kidney damage, cancer
Copper Gastrointestinal tract irritant, possible infant fatality, Wilson’s disease
Cryptosporidiosis Diarrhea, headache, abdominal cramps, nausea, vomiting, and low-grade fever resulting in weight loss, and dehydration
Dichlorobenzene(s) Suspected carcinogen
1,1-Dichloroethane Central nervous system depression, liver damage, suggested animal carcinogen
1,2-Dichloroethane Nausea, mental confusion, liver and kidney damage
Dichloroethylene Nausea, dizziness
Ethylenedibromide Decreased fertility
Fluoride Skeletal damage when present in high levels
Giardia Diarrhea, excess gas, stomach or abdominal cramps, upset stomach, and nausea resulting in weight loss, and dehydration
Heptachlor Possible tumor induction, carcinogenic in test animals
Hetertrophic Bacteria No health risks but is an indicator for ideal conditions bacteria growth
Lead Damage to nervous system, kidneys, reproductive system; cancer in rats
Lindane Chronic liver damage, anemia, leukemia
Methyl Tertiary Butyl Ether (MTBE) Limited Data, Potential Human Carcinogen at High Doses.
Mercury Kidney impairment, possible death
Methylene chloride Toxic
Nickel Signs of hyperglycemia and gastrointestinal and nervous disorders
Nitrite Toxicity, methemoglobinemia (‘blue baby syndrome’ in infants)
Per- and Polyfluoroalkyl Substances (PFAS, PFOS, PFOA) Limited Data, developmental effects during pregnancy, damage to liver, thyroid or immune system
Pentachlorophenol (PCP) Loss of appetite, respiratory difficulties, anesthesia, coma, death
Polychlorinated biphenyl (PCBs) Damage to skin and liver; nausea, loss of weight, jaundice, coma, death
Selenium Carcinogen; irritation to mucous membranes, dermatitis
Styrene Carcinogen; irritation to mucous membranes, dermatitis
Sulfate Laxative action
Tetrachloroethylene Central nervous system effects; confirmed animal carcinogen, anesthesia, death
Toluene Narcosis, irritation to eyes and respiratory system
Toxaphene Possible liver damage
1,1,1-Trichloroethane Narcosis, depression of central nervous system, unconsciousness, death
1,1,2-Trichloroethane Possible liver and kidney effects, possible carcinogen in animals
Trichloroethylene Central nervous system depression, loss of coordination, unconsciousness; strong irritant and carcinogen
2,4,6-Trichlorophenol Suspected carcinogen
Trihalomethanes (THMs) Effects to nervous system and muscles, loss of consciousness
Vinyl chloride Central nervous system depression, dulling of visual and auditory responses, possible death
Volatile Organic Compounds (VOCs) Effects range from respiratory, allergic, or immune. They include: Nausea, headaches, loss of coordination, irritation to eyes, nose and throat, and damage to kidneys, liver, or central nervous system, some VOCs are also carcinogenic and can cause cancer in humans and animals
Xylene Mucous membrane irritant, lung congestion, impairment of kidney functions
Zinc Muscular stiffness and pain, loss of appetite, nausea