The basic problem is that in most cases these products are not water-soluble. In practice, therefore, once absorbed by the human or animal organism, they can remain unchanged and accumulate inside the tissues. It is therefore a question of understanding what the effects on the entire organism may be. Since the scientific knowledge is incomplete at the time it has been authorized the use of only those products for which there is no danger of absorption. In particular for materials in contact with food only the use of nanoparticles that are not released and therefore do not remain in food is allowed.
Due to their widespread application, manufacture, and disposal, ENMs are released into the natural environment and so their accidental consumption is inevitable. The appearance of ENMs in the soil, water, and air could pose harmful threats for both humans and the environment, leading to serious health issues. Over recent years, it has been observed that epigenetic modifications greatly influence human physiology and development. There are innumerable pieces of evidence of epigenetic dysregulation in several human diseases, especially cancer, and much of drug discovery research is focusing on epigenetics.