http://www.techradar.com/news/samsung-galaxy-s9-may-feature-an-environmental-sensor-pollution-monitor

Air pollution is a major issues in cities around the world, and a new patent suggests Samsung is working on a sensor that sits inside your phone to help your monitor how bad for your health your environment may be.

The component appeared in a patent from a few years ago, which has just been published, suggesting it may either be in development for the Galaxy S9 or future phones.