Well, it's not like I react to using tissues (for blowing my nose), but I do wonder if I'm either slowly poisoning myself or decreasing my overall health. Here's why I am wary.
Ever take a tissue out in a beam of sunlight? See all those micro-particles flying around? When you blow your nose, you're having those stick to the inside of your nose, drying it out and providing the nose with more particulate matter to detoxify itself from (by creating more mucous).
Are your tissues white? They are bleached. The bleaching process is pretty darn toxic. Not to mention all the other countless processes that go into making each tissue a particular consistency, texture, density, softness, strength, etc. I'd imagine chemicals galore. I often find myself looking for an ingredients list on the tissue box. I think we'd be shocked.
I know it may seem trivial, but if you're someone who uses ~10 tissues a day like me, you might wonder how that constant intake of matter on one of our most sensitive mucous membranes of our body effects us. And don't forget, the nose is directly connected to the brain.
Am I being silly here?
Any time you smell anything you are breathing in particulates of that thing. Petroleum plant, any mill, fertilizer, etc. There are billions upon billions of foreign particles in every breath you take, but if it is something that gets to you, I suggest a reusable handkerchief. Or several if you have that kind of nose nuisance.