Water contamination can have a deleterious effect on humans.

What is the impact of wastewater on human health? Some illnesses from wastewater-related sources are relatively common health problems. Water borne diseases like gastroenteritis can result from a variety of pathogens in wastewater; other important wastewater-related diseases include hepatitis A, typhoid, polio, cholera and dysentery. Outbreaks of these diseases can occur as a result of, drinking water from wells polluted by wastewater, eating contaminated fish, or indulging in recreational activities in polluted waters. Animals and insects that come in contact with wastewater can spread some illnesses as well.

Even municipal drinking water sources are not completely immune to health risks from wastewater pathogens. Drinking water treatment efforts can become overwhelmed when water resources are heavily polluted by wastewater.

Pathogenic viruses, bacteria, protozoa and helminthes may be present in raw municipal wastewater and will survive in the environment longer periods causing health problems. Water borne pathogenic bacteria will be present in wastewater at much lower levels than the coliform group of bacteria, which are much easier to identify and enumerate (as No. of Total Coliforms / 100ml). Escherichia coli are the most widely adopted indicator of fecal pollution and they can also be isolated and identified fairly simply, with their numbers usually being given in the form of fecal coliforms (FC)/100 ml of wastewater.

There are various kinds of enteric microorganisms present in human excreta and animal manure; some of these are pathogens and some are non-pathogens. They can be classified into such major groups as bacteria, viruses, protozoa, and helminthes all of which cause health problems. Water based enteric pathogens commonly found in human excreta and wastewater, the diseases they cause, modes of transmission, and geographical distribution are shown below:

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Pathogen                     |                          Disease                           |     Transmission
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Bacteria                       |                          Cholera                           |     Person to person
Vibrio Cholera               |                                                                |
———————————————————————————————————————————————
Salmonella Typhi          |     Typhoid fever, Various enteric fevers       |     Person (or animals) to
Other Salmonellae        |     (often called paratyphoid),                      |    person
|     gastroenteriris, septicemia, (generalized |
|     infection in which organisms multiply      |
|     in the blood stream                               |
———————————————————————————————————————————————
Shigella Dysenteriae    |                Bacterial Dysentery,                   |     Person to person
and other species        |                Diarrhea                                    |
Pathogens Escheiria    |                                                                |     Person to person
Coli                            |                                                                |
———————————————————————————————————————————————
Viruses                       |     Poliomycetes Various cases                 |      Person to person
Poliovirus                    |     including respiratory disease,                |
Coxsackievirus            |     fevers, rashes, paralysis, aseptic           |      Person to person
|     meningitis, myocarditis                         |
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