Human waste, improperly dealt with, can cause disease. Human waste contains various bacteria that, if it enters the water supply, results in the harmful bacteria multiplying. Anyone using the water internally – for cooking, drinking, brushing teeth, washing dishes, swimming or other uses – could ingest the bacteria and get sick.
Dysentery is a medical condition caused by improper sanitation, and it involves uncontrolled, bloody diarrhea. This causes the body to dehydrate leading to death. While rare in the West, dysentery continues to kill millions in the third world every year.
E. coli bacteria can be fatal and is one of the things the operators of every water system works hard to avoid.
Personal cleanliness is also very important. If you are filthy and you injure yourself by breaking the skin, the filth on your body can easily enter your bloodstream where it can make you sick and cause a painful infection. Untreated infections can even kill you. Also, dirty clothing can lead to parasitic infestations, such as lice.
Dirty dishes breed bacteria which feast on any food left stuck to the dish. It is then easily transferred into the body when that dirty dish is used for cooking or for eating.
