Our way of life has intensified the quantum of pollution. No place can be called safe from pollution. What varies is the type of pollutant and the degree of pollution. Pollution is of various types such as gaseous pollution, water pollution, food pollution, radioactive pollution and so on. Of these types microbial pollution is the most important type of pollution for people in the medical or paramedical field.
Microorganisms are ubiquitous in nature.
There are certain opportunistic pathogens which, given a chance, can produce disease in human beings. Thus the mere presence of these microorganisms in a definite strength in various media can produce contaminants. Microorganisms like Salmonellae, Shigellae or Vibrios contaminate water, eatables, milk and milk products. When the contaminated eatables are consumed the individual suffers from typhoid, bacillary dysentary or cholera. Similarly, organisms like Staphylococci cause food poisoning by increasing toxins in food.