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Health Effects of Microbial Contaminants and Biotoxins in Drinking Water

Municipal Water Supply

  1. Raghuraman Venkatapathy1,
  2. Brenda Boutin2,
  3. Chandrika Moudgal2,
  4. Robert Bruce2

Published Online: 15 JUL 2005

DOI: 10.1002/047147844X.mw1705

Water Encyclopedia

Water Encyclopedia

How to Cite

Venkatapathy, R., Boutin, B., Moudgal, C. and Bruce, R. 2005. Health Effects of Microbial Contaminants and Biotoxins in Drinking Water. Water Encyclopedia. 1:277–281.

Author Information

  1. 1

    Oak Ridge Institute for Science and Education, Cincinnati, Ohio

  2. 2

    National Center for Environmental Assessment, Cincinnati, Ohio

Publication History

  1. Published Online: 15 JUL 2005


Contaminated, untreated, or inadequately treated municipal water is known to transmit disease-causing pathogens such as bacteria (Escherichia coli, Salmonella paratyphi, Bacillus typhosus, Vibrio cholerae), fungi (Penicillium, Candida), viruses (polio, reo, coxsackie), and protozoan parasites (Giardia lamblia, Cryptosporidium parvum, Entamoeba histolytica). In addition, some algae are not pathogenic, but produce biotoxins that may be harmful to humans at high concentrations. Treatment of source waters using disinfectants such as chlorine, chloramine, chlorine dioxide, ozone, and ultraviolet radiation has resulted in a dramatic reduction of waterborne diseases in the world today. However, waterborne pathogens may still be transmitted because of ingestion of water from contaminated service mains; microorganism growth in pipes and fittings; biofilms; sewage; inhalation of aerosols; or dermal contact with contaminated water such as in swimming pools. Waterborne diseases are usually acute in nature, are rarely fatal, and are often characterized by gastrointestinal symptoms. The severity and duration of illness is generally greater in people with weakened immune systems such as children, the elderly, and the immunocompromised, such as people suffering from AIDS.


  • bacteria;
  • virus;
  • protozoa;
  • algae;
  • fungi;
  • pathogen;
  • water contamination;
  • waterborne disease;
  • immunocompromised;
  • biotoxin;
  • microorganisms;
  • health effect