A federal appeals court has ruled against environmentalists who are trying to force the Environmental Protection Agency to regulate spent lead bullets and lead shot used in hunting and shooting sports. 

In a decision favorable to gun enthusiasts, the U.S. District Court of Appeals for the District of Columbia Circuit said Tuesday that environmental groups have suggested no way in which EPA could regulate spent lead bullets and shot without also regulating cartridges and shells. 

The Toxic Substances Control Act exempts cartridges and shells from regulation. 

The National Rifle Association and much of the pro-gun lobby intervened on the EPA's side in urging the federal appeals court to uphold the dismissal of a lawsuit by 101 environmentalist organizations. 

"Given that bullets and shot can become spent only if they are first contained in a cartridge or shell and then fired from a weapon," the environmental groups "have identified no way in which EPA could regulate spent bullets and shot without also regulating cartridges and shells," precisely what the law prohibits, said the decision by appeals judge David Tatel, a nominee of President Bill Clinton. The other two judges on the case were Patricia Millett and Cornelia Pillard, both nominees of President Barack Obama. 

More than 50 million hunters and target shooters in America use traditional ammunition containing lead components, according to pro-gun groups. Ninety-five percent of domestically manufactured ammunition is made with lead bullets or lead shotgun shells. 

Lawyers for the environmentalists say there are many effective alternatives, such as substituting copper for lead bullets and lead shot. 

Gun supporters say ammunition manufactured with alternative materials is more costly to produce and sell than traditional ammunition. 

At least six states have issued warnings about lead bullets and the risks for pregnant women and children. 

Lead is a carcinogen with significant health effects on people. EPA banned lead-based paint and lead-based paint products in 1978. 

In 1991, the government adopted a nationwide ban on lead shot in migratory waterfowl hunting after biologists estimated 2 million ducks died each year from ingesting spent lead pellets.