http://www.pcgamer.com/cities-skylines-pollution-battling-dlc-green-cities-is-out-now/

The coughing citizens of your Cities: Skylines metropolis can breath again—the game's eco-friendly expansion is out now. Green Cities, which is £9.99/$12.99 on Steam and Humble Store, adds more that 350 assets to the game, from Geothermal Power Plants to Yoga Gardens and Bee Havens.

The DLC also adds new specialisations for your buildings, all of which help keep pollution at bay. You can design self-sufficient apartment blocks, for example, or plonk down shops that only sell organic and locally-produced goods.