Indoor plumbing was introduced into the United States in the 1830s, initially in wealthy homes, and later, middle-class houses. Many did not have water taps and toilets until at least the 1880s—nonetheless, lead pipes were already identified as a source of lead poisoning. By the 1920s, some towns had prohibited the use of lead piping to deliver drinking and cooking water. That was over a hundred years ago. How, then, is it possible that our society allows lead in the environment to poison our wildlife?
There are two main ways lead enters America’s wild lands. First, via lead ammunition. Used primarily in deer, elk, and moose hunting, lead bullets shatter upon impact, scattering bits of lead throughout the body of the animal. When hunters dress out their deer, they leave the gut piles behind in the woods, to be eaten by the clean-up crew: carrion eaters like bald eagles, turkey vultures, ravens and crows. Ravens in Yellowstone National Park had blood lead levels five times higher than what is considered safe for humans during and after the elk hunting season. The Raptor Center at the University of Minnesota sees a dramatic increase in bald eagles suffering the effects of lethal lead poisoning during the deer hunting season. Shotgun shells with lead shot fall into wetlands, where the pellets sink to the bottom, to be scavenged by water fowl.
A second major way lead enters the environment is through lead fishing tackle. Lead sinkers are attached to a line to weight it when it drops into the water. Tackle like jigs—simple hooks with something fancy attached—have lead molded around the hook to sink it. If sinkers or jigs become detached and remain on the lake bottom, birds can ingest it as gravel in their gizzard. Loons, geese, and swans are susceptible to this kind of poisoning. Other species are also affected, birds you might not think of, including rails, moorhens and coots. Upland birds like pheasants, bobwhites and mourning doves have also exhibited signs of lead poisoning.
There are alternatives to using lead bullets and shot. Steel, copper, bismuth and tungsten are all substitutes for lead. Bismuth and tungsten are much more expensive. Steel is an affordable alternative. In Denmark, the Netherlands and Flanders, lead shot is banned. The vast majority of hunters use steel shot. They do not report less effective performance with steel shot, but because steel is less dense than lead, some tweaks are made to shot size, etc.
For bullets, copper or brass (a copper alloy) are adequate substitutes to lead. They are less dense than lead, so again, tweaks are made—to bullet size, weight, caliber, to facilitate the speed of a bullet. A big German study done in the field of over 11,000 shots found no significant difference between performance of lead and copper bullets. (source: www.leadammunitionguidance.com)
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