Natural water from rivers, ponds and lakes houses a plethora of microscopic organisms. According to Biology Reference, these organisms, which are not visible to the naked eye, can include plankton, bacteria, protozoa, viruses, algae and zooplankton. These organisms can vary from benign to dangerous, but there is no way of knowing what could be lurking in any body of water.
Natural water sources that have not been filtered have a high likelihood of being contaminated by outside sources. These causes of contamination vary, depending on the location of the body of water. Contaminants can include pesticide runoff, industrial waste, acid rain, animal feces or human sewage.
There can be many negative side effects associated with the consumption of unfiltered water. These include simple dehydration or more serious medical conditions that can have long-lasting effects. According to the National Park Service, giardia is one of the most common of these ailments, and the symptoms can include nausea, diarrhea, abdominal cramps and weight loss. According to the Water Encyclopedia, other common waterborne illnesses that are prevalent in the United States include Shigella, Hepatitis A, Salmonella and E. coli.
Avoiding consumption of potentially contaminated water is the best way to prevent any illness and negative side effects. If you must consume lake water, it is important to take the proper precautions to ensure the water is safe to drink. According to the Boundary Waters Canoe Area, natural water must be filtered, boiled or chemically disinfected (using treatments like iodine pills) before the water is safe to consume.
