As more people turn to the use (and overuse) of antimicrobial agents such as trichlosan in daily life, scientists are concerned that microbes are developing resistance to these agents.  Strains of microbes including Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa and Mycobacterium tuberculosis have begun to appear that are resistant to many chemical agents.

Immunologists have also begun to see increasing numbers of cases of autoimmune disorders such as hypersensitivities, asthma, inflammatory bowel syndrome and muscular schlerosis among the urban populations in developed nations.  This has led to the development of the hygiene hypothesis, that proposes less exposure to environmental microbes leads to "immunological overreaction" when such exposure does occur.

The general consensus today among concerned scientists is that we should decrease our use of antimicrobial compounds, allowing our own immune systems to respond accordingly to antigenic agents.