The plastic straw has been at the forefront of conversations about damaging man-made waste but cigarette butts have turned out to be an even bigger problem. An estimated 4.5 trillion butts are littered globally each year, The BBC reports, and their effects are incredibly harmful.

A study led by Anglia Ruskin University in Cambridge found that cigarette butts left in grass and soil cause stunt plant growth. The study also suggests cigarette butts are the most pervasive man-made contaminant and the most littered item worldwide. 

Researchers found that this waste cuts down the germination success of grass by 10 percent and shortens the shoot length of clover by up to 28 percent. Most cigarette butts contain a filter made of cellulose acetate fibre — a type of a bioplastic which is not biodegradable — and can cause the same damage to plant growth as un-smoked cigarettes.

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