The estimated 21 million to 81 million cases of diarrhea a year caused by food poisoning are just one of the minor results of this food safety hazard. In some people, particularly in children, the elderly, alcoholics, and those already ill with certain diseases, food poisoning may develop into a serious long-term illness. Certain types of food poisoning can even kill. Most food contamination is caused by organisms that occur naturally in foods. The organisms responsible for the most contamination are bacteria.
Bacteria are everywhere, even in the human body.
Fortunately, only a few types of bacteria are harmful. Viruses are also responsible for some food-borne illnesses. Still another source of contamination is mold. Molds vary in their ability to cause illness, but some are deadly. Some contamination, such as spoiled fruit, is easy to see and smell.