Smoking tobbacco has generally been proven bad for people. Tar and
nicotine. What kinds of effects on a human's body would smoking
lavender plants through a water-filtered pipe produce? More
specifically 'lavandula intermedia' and 'salvia nemorosa'.

Nicotine is an addictive drug --but it's the smoke that is most
harmful to the human body. If the lavendar was dried and smoked as
tobacco is, it would be just as harmful. Smoke is smoke, whatever the
source.

Cynthia is right, though drying your own lavendar would avoid all the
nasty stuff added to cigarettes-- uric acid, ammonia, bat poop (where
d'ya think they get uric acid and ammonia from? Go look up guano at
Wikipedia!), formalin (that's what embalming fluid is made from), and
a host of other even worse stuff.