A modular system for plants and air purification having a plant module with a containment portion for holding a plant growth medium and a conduit for passage of air therethrough. The modular system also contains an exhaust module having an inlet aperture for receiving air flow from the plant module, an outlet aperture and an air pumping unit arranged to pump air from the inlet aperture to the outlet aperture. The plant module and exhaust module are connectable one with the other, and wherein when connected air flow is permitted between the two units.