Formaldehyde is a known cause of sick building syndrome. Maybe you don’t know that formalin is an liquid solution of formaldehyde. And also formaldehyde is included in both cigarette smoke and e-cigarette vapor.
So even if you are a non-smoker, when you are exposed to second-hand smoke, you are affected by it and will feel pain in your nose, throat and eyes.
My noisy neighbors love toxic things including smoking heavily. And their smoke come into my house every day. I taped all of the cracks in my room. And I use two high performance air purifiers. It improves the air in my room, but I still feel pain pinpricks and inflamed sinuses. These symptoms have intensified and I cannot sleep even if I wear an activated carbon filter mask.
I had never experienced sick building syndrome before, but I was reminded of formaldehyde. I used a spray with a formaldehyde enzyme. So immediately I could breath deeply and my sinuses improved. Even the floor felt differently on the soles of my feet. I felt that my room became bigger.
I used many products to remove all the smoky odor, but there are still toxic residue, like formaldehyde. Formaldehyde is colorless and sometimes odorless. I wiped the floors with a cloth every day. This works to remove odors to some extent, so it is hard to detect toxins through smell.