* This is only a theory and I have nothing to prove it.
It sure looks like a contamination issue of a component used frequently in vapable THC and can find its' way somehow into eliquid (nonstandard use). This might explain the so called exclusive nicotine users (wish they were tested).
One thing that jumped to mind is PEG400 which was used sometimes back in the day in eliquid and fell out favor. And it is being used now more frequently in MJ carts. I don't know much about MJ but saw PEG sold on few websites as solvent for MJ extracts. Nothing wrong with PEG but it is liable to contamination and higher weight PEGs (2000,4000 etc.) are waxy/oily. Who knows?
Again, this is just speculation.
Legit theory. My take…
No company, be it food, medical or other, is void of mistakes. Our food industry, which is highly regulated is proof of this with contaminated outbreaks. We’ve all seen it, and I am sure some of us might have become ill from it (I have).
But with a contaminated food outbreak, health officials/agencies put forth great efforts into finding the source and eradicating it. This is actually a difficult task given symptoms of food poisoning can take some time to become noticeable, and within that time, the victim will have consumed other foods. But agencies are still able to find the source and do so within short period of time given the complexities.
Ejuice manufactures (legit ones) and or suppliers are also not void of mistakes. Should there be a contamination, or even a change in ingredients, agencies need to act, source and eradicate to prevent further illnesses. If PEG400, or any of its variants, was used as a replacement ingredient, and is the cause of the smaller percentage of claimed exclusive nic users, then this should be easily identified and all products containing this ingredient has to be recalled. If our agencies can find the source of a contaminated food outbreak, then finding the source of a contaminated ejuice should be that much easier. Patients have admitted to using nicotine ejuice, samples should be requested and tested.
Perhaps this is actually taking place – but I have not seen any reference to testing ejuice