Last week, we visited Nahant Marsh in Scott County, a beautiful wetland with an ugly past. The site had been so contaminated, it had the distinction of being a Superfund project. The story has a happy ending: a massive clean-up was successful, and I saw the great work done today for wildlife management and environmental education. I interacted with visitors exploring the natural beauty, and indeed I enjoyed it myself. Yet, this is really but one chapter in a very long story of poisoning, both people and our environment, with lead.
Lead is a versatile and important metal, in use for many centuries, most famously by the Romans: the chemical symbol for the element (Pb) echoes its ancient name (Plumbum) and an early use. Yes, it was—sometimes, still is—part of water systems. Its toxicity has also been recognized since ancient times. Although we have steadily phased out the use of lead in our homes (paint, water pipes) and cars (gasoline is now all “unleaded”), there is still a common use today, and it spreads the metal everywhere, including into my beloved wetlands.
The contamination at Nahant came from this other widespread use of lead: as an ingredient in ammunition (bullets, slugs, shot) in firearms, or in weights used for fishing (“sinkers”). These devices leave the hands of the shooter or angler, and enter the environment, where they cause significant harm.
As it turns out, lead entering soil or water doesn’t biodegrade, or oxidize away to nothing, or otherwise conveniently disappear. It remains stubbornly what it is…lead…a toxic metal. When discussing this with students, I bring some old Civil War-era lead ammunition (Minie balls), still routinely being dug up on battlefields 150+ years later. Lead is the toxin that keeps on giving.
What it gives to wildlife, is illness and death.
I’ve heard the stories from naturalists, wildlife rehabilitators, and toxicologists. There is no safe level of lead for us, and no reason to think it is different for animals; lead in the environment harms wildlife and their ecosystems. The stories of animals like eagles being sickened and dying are very sad indeed.
Read those articles I link to for more information, even some X-rays showing lead pieces or its effects. The basic idea is simple enough: lead deposited in soil or water or left in an animal carcass, may be consumed by living things, thereby entering a food chain. A bullet or slug that seems inert, unlikely to cause a problem, can be digested by a predator or scavenger; the stomach of the predator or scavenger dissolves the lead, and it is absorbed, poisoning the animal. This lead transport may happen immediately, or be delayed, depending on whether the lead drops in moving water, is embedded in a carcass, or otherwise taken from prey or carrion. As I’ve described in previous posts, no ecosystem is truly closed; materials and organisms move in, out, and around. Lead in the stream may be taken into a fish, then carried off by a Bald Eagle, or lead in parts of a deer left on the hunting ground is consumed by a scavenger and moved far from the site. The lead goes from water to wetland to dry land and back again.
An excellent essay by a hunter asks us to reconsider the use of lead ammunition. Wildlife biologists and hunters recognize the hazard of lead ammunition, and are working together to help us transition to non-toxic alternatives. Whether through countless individuals making a switch, or collective action to shift broad patterns of culture and economics, or other mechanisms…we can make this change. We can “get the lead out.” Every time a purchase is made, we can be part of the solution.
I think it would be quite fitting, if the last chapter of this toxic tale were written here in Iowa. The man who, more than any other, alerted us to massive worldwide lead contamination was a man from Iowa, Clair Patterson. Dr. Patterson worked tirelessly, at great personal cost, to eliminate lead poisoning from our lives—he lived to see us outlaw leaded gasoline, lead in paint, and lead in food. Now, let’s do our part. Let’s stop contaminating our wetlands and all our other ecosystems. Iowans are doing great work on this, and we can build on those efforts. Let’s Get The Lead Out.