The City of Johannesburg shared a video warning about the dangers of smoking on World No Tobacco Day on May 31.

The video, shared on the city’s Twitter page, showed an example of healthy lungs and an example of smoker’s lungs. The healthy lungs appear pink and full while the smoker’s lungs appear somewhat smaller than the healthier lungs with a grayish-black coloring with white blotches.

According to the official in the video, the white spots on the lung show that there is cancer in the organ. The woman also explains that smoking does not just affect the lungs but also the kidneys, the bladder, the mouth, and tongue. As of writing, the post has over 1,800 views and over 80 retweets on Twitter. Credit: City of Johannesburg via Storyful