Personally I am allergic to cannabis and I suffer major respiratory symptoms when I vaporize. My life is plagued by serious allergies. Every time I eat food my lungs fill up with thick mucus all the way from my mouth, down throat, in intestines.
I have to manage these symptoms 24/7 by using essential oils with and without steam inhalations, a very restricted diet (as diff foods cause a diff level of excessive mucus production), a variety of supplements that help like oil of oregano, spices like cayenne, turmaric, cinnamon, cardamom, garlic etc.
Most supplements cause an unbearable amount of mucus production it is unbearable, like over 95% of supplements if not higher.
I have had long term chronic infections in my lungs since 2005 due to Lyme disease- at least 2 infections in both of my lungs at a time, every single day sonce 2005, at times as many as 6 seperate infections in both lungs at a time, but never less than 2.
So whatever I do I have to live to manage the symptoms. I cant take any other drugs, alcohol is far worse than cannabis in any method, it is very hard for me to relax and de-stress and enjoy life with severe long term depression (due to Lyme disease and being unwell, directly (brain chemistry) and indirectly due to not being able to live life fully and sleep, relax etc, work, have fun basically.)
Hence, I still vaporize cannabis as it is one of the few things I enjoy, amd it enables ,e to enjoy other things in life. I go crazy with stress otherwise so it is the lesser evil, but the allergic reaction is very hard work to deal with.
All this said, it is clear to me, being very in tune with my body and symptoms, that vaporizing weed does enormously benefit my lung health, which is ironic with my allergies!
When my infections are much lower, the allergies are much less, as infections basically cause allergies in the particular area they are located. So my respiratory allergies could and likely will vanish if and when all my lung infections are gone for the first time in 12 years.
I am certain that vaping does support lung health and function, but accept that it does also cause some temporary issues/irritation in the process, largely to do with the heat I think.
A BIG factor in this debate though is the chemicals in weed. The chemical ferts cause irritation, especially to the throat and vocal chords. And they also cause damage, which clean weed does not, however irritating.
I am so badly allergic to all chemical ferts I can only vape weed grown without any fertiliser, except fish blood amd bonemeal from all the organic ferts I have ever treid yet- Im allergic to practically all organic ferts too.
Nature can cause irritation without actual harm, chemicals and synthetic causes irritation AND harm.