Proverbs 10:26 (NKJV)
26 As vinegar to the teeth and smoke to the eyes,
So is the lazy man to those who send him.
According to my research, acids, such as vinegar, eat away at the enamel of teeth. This erodes the enamel and can cause sensitivity in teeth as well as cavities. Both of these situations can be very painful as most everyone knows. This pain can be either a nagging, throbbing type of pain, or it can be a sharp, stabbing type of pain.
Wood smoke has been proven to depress the immune system and can also damage the cells that protect the linings of the lungs. It can cause coughs, headaches, eye irritation, and irritate the throat. It is especially dangerous for children and anyone with asthma. Anyone that has been around a campfire knows that you want to stay upwind, and away from the smoke.