yea but even the smell from the neptune's harvest fish smells like fresh fish....i don't think it smells bad at all, i use it every run. for years, plants love it
and then yea, if you're applying any dry organic nutes, you should be wearing a dust mask because its just really bad for your lungs - but as far as diseases, most of them need a living host to stay alive....so i'd worry more about the friends you have over your house than the dry nutes your applying to your plants/soil
and then as far as using blood meal, i don't use it because it's pretty hot - i just don't see a need for that kinda heat....there's just better alternatives