The Army has stopped producing so-called "green" training rounds, because of research showing that the bullets' main ingredient may be more toxic than previously thought. But that element, tungsten, is also in an array of other ammunition and munitions, as well. Which means all sorts of rockets, missiles, and anti-tank rounds may present an environmental hazard and a health risk.
But scientists later learned that embedded tungsten alloy fragments can cause tumors. A 2007 memorandum from the Under Secretary of Defense advises that "in light of our present knowledge of the potential health risks associated with tungsten/nickel/cobalt alloys, please have your acquisition managers and munitions developers and researchers consider alternative materials in developmental munitions programs." The discovery that tungsten, by itself in the environment, is also hazardous may escalate things to a new level. Could it put tungsten on a par with DU?
Part of the problem is that so many types of weapon use tungsten:
- The GNU-44 Viper Strike missile, carried by armed drones, has a tungsten sleeve to produce antipersonnel shrapnel.
- The 130-round-per-second Phalanx anti-missile Gatling gun, deployed on U.S. and Royal Navy ships, originally used DU rounds. They were replaced with tungsten, for environmental reasons.
- 120mm anti-tank rounds, use tungsten as an alternative to DU in training. So do the 25mm anti-tank rounds, on board the M2/M3 Bradley fighting vehicle.
- Armor-pirecing .308 M993 rifle rounds.
- The 120mm M1028 anti-personnel round, fired by the Abrams tank. It's basically a giant shotgun shell loaded with 1100 tungsten balls, each 3/8th of an inch big.
- Dense Inert Metal Explosives, the "focused lethality" munition used by the U.S. and Israel. It contains micro-shrapnel made of tungsten powder.
- Some 70mm rockets fired by Apache helicoptersrelease tungsten flechettes.
… and so on.
The British Army is already looking into the tungsten problem. A study of possible implications found that there was tungsten in the ground water of at least one UK tank firing range, and recommended that further studies be carried out.
Meanwhile, the U.S. Army seems to be taking a schizophrenic approach - stopping production of tungsten-based training ammo, while looking into using it as a DU-replacement in even more rounds.
Lead – the classic ammo ingredient – is firmly established. (Although some U.S. state laws make it illegal to use at firing ranges.) So is DU also appears rooted in place. But the trend towards more environmental awareness is a continuing one and would be unwise to assume that anything defined as a toxic health hazard is going to remain in the inventory indefinitely. This might exasperate those who accept that all weapons are dangerous... but it's not going to get them around the law.
We may end up in a situation where neither depleted uranium nor the only known alternative are politically acceptable. Heavy metal penetrators are an essential tool of modern armored warfare. What is needed is a new material entirely, and that is going to be quite a challenge from a physics and engineering point of view. And then it will need to be proven safe, which may take quite a while.
[Photo: U.S. Navy]