Lead is a known hazardous substance, and is used quite a bit in electronic components. When these electronic components get dumped , the lead in it contributes to environmental pollution.
So most electronics manufacturers strive to reduce the amount of lead content in their products. Sort of like a Euro III pollution norm for cars, there's a regulation for the amount of lead in components as well
well studies show that most of the electronic waste(E-waste) produced is dumped in developing countries like india, china, pakistan, etc..
and lead is a major contributor of soil, water and air pollution causing harm to people living near the dump site etc.
so i guess kudos for AMD for doing a good things for the nvironment