#NationalCleanAirDay trended at 1 on UK twitter for 5 hours on National Clean Air Day 2017, reaching 38million people!

On 15 June, National Clean Air Day caused a buzz across the U.K. Thousands of people got involved in schools, businesses, hospitals and communities - making pledges, going car free and raising awareness of air pollution.

Here are some of our favourite tweets, photos and stories from the day:

Thank you to everyone who helped to make National Clean Air Day such a success!