Where did you search? In the Bible?
About 5 or 6 years ago there was a lot about these things on the news… This was before a well known P started the the fake news era.
This is what candles.org say about candles:
There is no such thing as a soot-free wax. All organic compounds when burned will emit some carbon (soot) due to incomplete combustion. Sooting is primarily a factor of wick length and flame disturbance.
Soot x soot x xxx = Smog
I should have pointed this happen especially if you blow out the flame on a cheap tea light, then you add small aerosol particles to the air. It is even worser if the light burns out of itself and you can then see the black smoke. They also found a significant difference between cheap candles with different wick materials and stearin and beeswax lights.
In modern houses there are ventilation that reuse 80 % of the air. Then these particles circulate for a while. I suggest you don’t use a mask at home and then these particles ends up in your lungs and punctures your lungs just like smog particles do. This is easy for me to understand.
And I hope for my own sake and all others that when it is similar to smoke 200 sigs it is the smog during a season not when you blow out a single light. Most people use these lights all day long in the winter season.
The soot traces are seen on ventilation ducts. As soon as you renew the filters in the ventilation and stop using candles these traces disappear.
In an open office environment with about 60 desks I used to be a part of we stopped using these lights, and the afternoon air was significant better after we started using electrical tealight instead. Less cough, more batteries used, less sick leave and more productivity.
Coincidense? Not at all. And I have advised many to stop using candles indoor and they have reported the same, cleaner filters and cleaner ducts.
And you will cough less, just like when you stop smoking or don’t need to be a passive smoker.
Not convinced? Start a research for yourself. The one you did and refer to has no value.