From the Sinterfire website: 

This spring, the Army will begin issuing an environmentally friendly "green bullet" that contains a non-polluting tungsten core instead of lead, which contaminates the soil and air around firing ranges. The armed forces use between 300 million and 400 million rounds of small-caliber ammunition each year. The first 1 million green 5.56-mm bullets will be used in the Army's M-16 infantry rifles. Officials hope to get all the lead out of bullets used in all the services by 2003.

From the Corbin website at http://www.corbins.com/powder.htm

However, three factors today have brought about renewed interest in PM (Powdered Metal) bullets:

• Environmental concerns about range contamination from lead.

• The increasing cost and decreasing availability of conventional bullet jackets.

• The tremendous growth of home and small business swaging systems, which can easily handle powdered metal forming techniques.

From the Gunowners website at  http://www.gunowners.org/am9501.htm

(January 18, 1995) -- New rules issued by the Environmental Protection Agency could lead to the banning of lead bullets. The EPA will investigate whether it deems lead bullets as toxic to the environment and will then consider implementing either a complete ban or partial restrictions on the manufacture of such bullets.

From the Emedicine website on lead toxicity http://www.emedicine.com/emerg/topic293.htm

Lead poisoning is probably the most important chronic environmental illness affecting modern children. Despite efforts to control it and despite apparent success in decreasing incidence, serious cases of lead poisoning still appear in hospital EDs, clinics, and private physicians' offices.

From the Rehabitat website at http://www.rehabitat.org/lead.htm

According to The Raptor Center in Minnesota, most lead-poisoned bald eagles are admitted in a period coinciding with deer-hunting seasons in that state and nearby Wisconsin and Michigan. Ingestion of bullet fragments while scavenging gut piles is suspected.

From the Naples Daily News in Florida at http://www.bonitabanner.com/

Recent tests showed one well behind the range had twice the amount of lead allowed in drinking water by the U.S. Environmental Protection Agency. Another well had an acceptable level.

This is amazing! A list of  hundreds of clinical studies on the toxicity of lead.

A study done by Oak Ridge National Laboratory for the US Department of Energy states in part:

The firing of small arms ammunition is a significant environmental and health problem. The ammunition's projectile which is traditionally composed of lead and copper, is the principal source of pollution. Rifle, pistol, and shotgun projectiles composed of materials which are not significant environmental or health hazards, and that are economically recyclable are being developed. The primary objective is to develop high density, non-toxic bullets. The projectiles must meet all performance specifications of current bullets, but must significantly reduce or eliminate exposure of the shooter to hazardous materials and reduce environmental contamination.

The Swedish Government has legislation in place to ban the use of lead in bullets by the end of 2007. http://www.pistolskytte.org/info/Swedish_Government_will_Ban_Lead_Ammunition.html

From the Seattle PI website at http://seattlepi.nwsource.com/national/lead23.shtml

One long-term environmental issue that has attracted the service's attention in recent years is the potential environmental threat from lead-based ammunition and a research initiative to come up with a "lead-free" bullet.

The Danish Government introduced legislation to regulate and eventually phase out all use of lead http://www.mst.dk/news/02070000.htm

The days are numbered for lead, a heavy metal harmful to children’s learning ability, behaviour and intelligence. On November 14th the Minister for Environment and Energy Svend Auken signed a new statutory order banning the use of lead in a large number of products in Denmark.