From swimming pools to wells, chlorine is a common chemical used to disinfect water sources.
Due to safety concerns, hypochlorite (bleach) is the most commonly used compound to conduct shock chlorination1. Hypochlorite is used in one of three forms: commercial bleach (approx. 3.5-5% concentration), calcium hypochlorite (Ca(OCl)2;65-70% concentrated), or sodium hypochlorite (NaOCl; about 12% concentration)2
Frequently, microbial factors infiltrate water sources through fecal matter. Many types of bacterial pathogens can initiate waterborne illnesses, including enteric bacteria, protozoa, or viruses3.
Helicobacter pylori is known to cause gastritis and peptic ulcers.
Studies done in Peru4 and Japan5 have shown the presence of the bacteria in public water sources, proving its possibility as a waterborne microbe.
Cryptosporidium parvum is a type of parasite capable of causing gastrointestinal illness. Unlike Helicobacter pylori, however, Cryptosporidium has been proven to be unresponsive to chlorination6.
Scientists are not content with shock chlorination. As technology advances, methods to improve both testing and disinfection are created.
4 Hulten K., Han S.W., Enroth H., Klein P.D., Opekun A.R., Gilman R.H., Evans D.G., Graham D.Y., El-Zaatari F.A. "Helicobacter pylori in the drinking water in Peru". Gastroenterology. April 1996. Volume 110(4). p. 1031-5.
6 Bukhari Z., Marshall M.M., Korich D.G., Fricker C.R., Smith H.V., Rosen J., Clancy J.L. "Effects of ozone, chlorine dioxide, chlorine, and monochloramine on Cryptosporidium parvum oocyst viability". 1990. Appl Environ Microbiol 56(5). p. 1423-8.