Question

What are biological sources of contamination?

Answer 1

Contamination is the action or it is considered as the state of making or being made impure by polluting or poisoning.  

In general, contamination is the presence of an unwanted constituent, as well as contaminant in a material, physical body, workplace, natural environment.  

It can lead many problems.  

Of course contaminants are also considered as the physical or radiological, biological, chemical substance.