The best scientific studies are most likely in the secret archives of the perfume industry.
It is very unlikely that they do not know what damage they do.
The most thorough public scientific studies done, up to now and to our knowledge:
A very thorough and alarming study about perfume by Greenpeace, published in Feb 2005:
A thorough study of the situation in households (perfume chemicals in household cleaners) by the German Umweltbundesamt (Environmental Agency), published in April 2006:
"Duftstoffe: Wenn Angenehmes zur Last werden kann"
"Fragrances: When Pleasant can turn Burdensome"
That very study is not published anymore. But if you search there for "Duftsoffe" (fragrance) you will get hundreds of pages of warnings and information about the dangers of perfume.