There are many environmental arguments in favour of switching to LEDs, for example, they do not contain mercury, unlike most fluorescent bulbs that contain large amounts. When broken, discarded in a landfill or incinerated, it can cause fatal effects; it contaminates the air, surface water, groundwater and causes ultraviolet radiation burns. This is not only dire for the environment but for you.  

Source: https://www.kingsbridge-today.co.uk/news/making-the-switch-to-led-lighting-561374