Yes. The recycling of old lights taken down during a bulk change is the responsibility of the installer.
The tender for installation of the lights specifies waste disposal requirements, which includes the recycling of around 98% of the old lights.
For example, the glass collected is recycled into products such as glass wool insulation for homes. The mercury is distilled and reused in the dental industry to manufacture amalgam. The aluminium body and other fixed components (for example, steel screws and copper wires) are collected and end up as ingots used in industry.