Interesting.

"cigarette filters take years to be broken down in the open"

Source: https://en.wikipedia.org/wiki/Cellulose_acetate

Not that I doubted you at all, I just wanted to get a bit more detail. The whole article is rather interesting in how we've used CA as a society and what happens to it. In some cases, according to the above, the product can be biodegraded using cellulaise and exposure to 280nm or smaller wavelengths of light to promote the process; the cellulaise is only present in very bio-active soil, which isn't common in places where smokers will be tossing their butts, the filter is usually protected by paper wrap, so even sitting in the open where it can be bombarded with direct sunlight, there's going to be a significant delay before any UV can reach the CA in the filter.

I'm extrapolating from the Wikipedia article for that last bit.... but it's logically sound. Between the difficulty of UV reaching the CA, plus the absence of any additional substances to aid in the degradation of the CA, it would take substantial time to degrade. Though it's derived from either cotton or wood cellulose.

It's fascinating stuff.

I've never regularly smoked cigarettes, and I've always had an issue with people just flicking their butts wherever they want. Now I have scientific information to support that discomfort, so thanks