@CNN: Air pollution in national parks is nearly the same as in 20 major US cities, a newly published study finds https://t.co/UJV2kyOwDc https://t.co/dX2ydwZ64q

July 19, 2018 / The Arbiter / CNN

@CNN: Air pollution in national parks is nearly the same as in 20 major US cities, a newly published study finds https://t.co/UJV2kyOwDc https://t.co/dX2ydwZ64q

Air pollution in national parks is nearly the same as in 20 major US cities, a newly published study finds https://t.co/UJV2kyOwDc pic.twitter.com/dX2ydwZ64q

— CNN (@CNN) July 19, 2018

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