What are particulates? Why are they important?

Particulates are small particles, roughly one to a few tens of micrometers in size, suspended in the air. They are individually invisible but in large concentrations, they may give a "color" to the atmosphere. The extent to which particulates are present in the atmosphere are an important indicator of air quality.

Explanation:

They are important because they help us to begin the process we want

"1. it should be, it has been for about 20 years, and it's really not much different in the end than breeding animals to have particular traits. there are always concerns about genetically engineered animals/plants affecting the environment in unexpected negative ways, but i can't think of an example where the fears didn't turn out to be baseless.  

first, as you point out, it would be a great advance in pharmacology, to be able to tailor drugs and their doses to me. the pros involve better medical treatment. the cons involve privacy issues like insurance companies denying coverage to people with genetic risk factors. looking at dna markers wouldn't affect the frequency of genetic diseases, but it would allow detection of them earlier. and ok, actually i suppose that if people used this information to avoid having children with genetic diseases, some might decrease in frequency."

this is more of a statement than a question. is there answers to go along with this, or is it opinion based?