For those who didn't know, the Army's first attempt at lead-free "green" ammunition at Camp Edwards in Massachusetts has resulted in a legal battle. Apparently the new ammunition is more environmentally toxic and dangerous to the water supply than the lead ammunition it replaced. Good background on Camp Edwards can be found here:
http://archive.capecodonline.com/spe...tungsten17.htm
In more recent news, during three separate incidents in December 2008, over 40 Norwegian soldiers training with the HK416 and Nammo's "green" ammunition reported symptoms such as nausea, headache, sore throat, fever, cold sweats, sleeping problems, and pain in the chest, neck, mouth, and joints. Use of the ammunition has been banned pending further investigation.
Source.
As shooting and hunting tend to be outdoor sports, I know a lot of us are concerned about our impact on the environment and want to minimize it; but both of these incidents demonstrate that some of the alternatives could be potentially more harmful than what they replaced.