Originally from http://ledlightbartruck.com/top-led-light-bar-review/
Unlike conventional lighting solutions that contain mercury, LED light bars do not contain any harmful materials. Some health conditions have been attributed to carbon heavily present in the traditional fluorescent light bulbs.
The light bulbs we have been using in the past are made of glass filaments on the cover. This makes them susceptible to breakage when hit.
Luckily, that is not the case for LED bulbs. They are made to be versatile especially for use outdoor. This is arguably the reason why automobile companies have embraced the equipment.
More at Eco-friendly bulbs