Eyewitness This: Cigarette butts are largest man-made pollutant, researchers say

Recent laws have been focusing on reducing the amount of plastic straws that go into the environment, but it turns out cigarette butts may be the worst offender.

More than 4 trillion butts are littered around the world every year, and the impact on the environment is severe. Scientists from Anglia Ruskin University in Cambridge found cigarette butts left in grass and soil stunt plant growth. Once they go into the ocean, they accumulate at the bottom of the sea.

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