Hi, folks. Occupational health and safety professional here.
I post a lot of questions about vaping here, because as you can see, I'm new. I don't know anything about vaping.
One thing I do know, however, is occupational health and safety, which is the field from which the scientific background comes that has deduced the dangers of inhaling silica into the lungs. So I thought I'd give a little back to the community and post what I know.
1) The primary health hazard of silica is silicosis. This is a disease that will probably kill you. I am not saying silica wicks cause silicosis. Your lungs contain macrophages. Tiny police in your lungs that trap particles and intruders, and try to expel them through your lungs natural elevator system. However, when macrophages get their hands on silica crystals, they lodge themselves in the wall of the lung, and can't let go. The macrophages die, and you're left with scars. Over the course of many years, the scars caused by the crystals make lung function decline, resulting in the diagnosis of silicosis. Silicosis is not reversible and there is no cure. Again, I am not saying that silica wicks cause silicosis.
2) There's two types of silica in regards to causing silicosis. Crystalline silica is the material that causes this disease. Amorphous silica does not. Someone mentioned the health effects of "glass silica" entering the lungs. If these wicks are indeed made from glass, they are by nature *not* crystalline silica. Glass is an amorphous material.
3) A reader thought that silica was the cause of some lung issues they were experiencing after vaping for a month or so. Unlikely. Silicosis takes many, many (10 - 30) years to develop. There is no instant effect.
4) Most occupational exposures to silica that result in silicosis are from sawing or drilling things like concrete that contains silica, working with certain types of insulation etc. These occupations are 5 days a week of MASSIVE amounts of crystalline silica hanging in the air. This is not to make light of the inherent dangers of crystalline silica, just to give you a comparison of what people who really do get the disease are exposed to.
5) Someone mentioned that putting a cotton or cloth pad between you and the wick might save you from the perceived danger of the silica wick. No. You need what is referred to as a P100 filter to contain the tiny particles that crystalline silica would produce.
6) I don't know if the silica wicks are amorphous or crystalline. This is something I'd need to find out.