Buchanan is a bald eagle that was found injured in Pennsylvania. Unable to fly, "Buck" is now a permanent resident of the Tuckahoe aviary and helps rangers to educate the public on the human impact to wildlife. (Photo by Will Parson/Chesapeake Bay Program)
Humans are potentially at risk. The harm to eagles is current, documented and lethal, but eagles are by no means the only beings affected. Due to their particular biological makeup, eagles and other raptors become terminally poisoned at low doses, making it an acute situation. Humans do not show the same immediate and devastating symptoms, but lead levels are shown to be much higher in those consuming game meat—particularly ground burger game. There is also the concern that, for humans, small amounts of lead over time can do more harm than a large amount at once.
The "What you can do" section of the article discusses the exposure of humans to lead levels in game meat and link to an article about human ingestion. In this Iowa investigation, it was found that some samples of deer meat showed lead levels up to 194 times higher than the threshold set by European Food Safety Agency for lead levels in meat. It went on to disclose that the state was not looking at game meat as a source of lead for the community, and quoted University of Colorado medical professor Michael Kosnett as stating "You lose more I.Q. points at low levels of exposure, per increment of blood lead, than you do at higher levels."
The "How is lead entering the system?" section links to an article in Scientific American about the amount of lead present in wild meat. This article quotes Dr. William Cornatzer, a hunter, on his reaction to seeing evidence of lead poisoning in condors and the immediate link he made to the lead he and his family would have ingested, saying, "I knew good and well after seeing that image that I had been eating a lot of lead fragments over the years."
Hunting helps to stabilize the deer population, creates revenue for conservation and stewards of the environment through hunters, and provides an excellent source of lean meat—though as we all discover new information about unintended consequences and harms, such as the findings on lead fragmentation, we can continually update our practices for the good of both humans and wildlife.
Iowa investigation of human lead levels from game meat: http://www.kwqc.com/content/news/TV-6-Investigates-Lead-in-venion-Iowa-health-officials-actions-421225163.html
Scientific American article on lead exposure from wild meat consumption: https://www.scientificamerican.com/article/wild-game-deer-venison-condors-meat-lead-ammunition-ban/
I am wondering why I see articles like this on the potential harm to eagles from lead ammunition, but I have never seen an article about potential harm to humans. It only seems logical that if raptors are poisoned by lead ammunition wouldn’t humans be also ?
I suppose my ultimate concern is without stating clearly that lead poisoning is an insignificant, mortality factor for raptor populations, the general, human population can easily be led to believe deer hunters are wantonly killing birds of prey. A simple Google search for "lead poisoning, eagles" brings up articles by National Geographic, The Washington Post, and The Guardian on the matter. That being said, I will now hunt with copper bullets for deer; I just wish more coverage was devoted to plummeting small, game populations which coincidentally, are prey for raptors.
Great question, Vince! Connecting landscapes to provide habitat is imperative to having a healthy watershed. The Bay Program's Vital Habitats Goal Implementation Team, along with its partners, is dedicated to restoring a network of habitats for vital species. You can read more about the Vital Habitats Team in this highlight article: https://www.chesapeakebay.net/news/blog/by_supporting_key_habitats_we_support_the_ecosystem.
Lead poisoning is not a significant mortality factor for the eagle population, but it is a completely preventable and painful death for those that are affected. The implications of lead contamination extend to humans, who are also ingesting lead fragments in venison: https://www.scientificamerican.com/article/wild-game-deer-venison-condors-meat-lead-ammunition-ban/.
I like the thoughtfulness and balance of this article. My only question, however, is lead poisoning a significant stressor/mortality factor for the entire population? With raptor's amazing comeback in response to federal protections and rapidly declining small game populations, is lead poisoning in a small portion of raptors truly a cause for concern when populations for these birds of prey are literally soaring? As a hunter, I would like to see more attention paid to fragmented landscapes and reduced habitat for small game as these animals don't have federal protections such as eagles, hawks, and falcons.
Eagles are often highlighted for this issue as our national bird, but most avian scavengers (vultures, ravens, condors out west) also experience these high lead levels. In New England, the leading cause of loon death is lead poisoning—in this case, from lead tackle rather than ammunition. Birds are extremely susceptible to lead, and the damage is extensive.
I found only a single study addressing large carnivores. Possibly because their diets are more varied, they are larger, and they have different biological symptoms, they are not as susceptible as our birds. Humans, too, ingest lead in venison, but the effects are not as immediately apparent as they are with birds. Grizzlies had higher lead levels, but the cause is still unknown because it did not change with the hunting seasons.
As for secondary ingestion, lead is eventually stored in the bones of an animal. If a large predator were eating the bones of a lead-contaminated smaller animal (not usually the case), the predator's lead levels would undoubtedly be much higher. Biological magnification (levels being higher in an animal that eats multiple contaminated animals) does not seem to be occurring with lead toxicity, though there was little research available for wildlife outside of birds on the topic of lead.
Ravens: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4229082/#pone.0111546-Gordon1
Loons: http://www.audubon.org/news/toxic-fishing-tackle-hampering-loon-recovery-new-hampshire
Large carnivore study: https://scholarworks.umt.edu/cgi/viewcontent.cgi?referer=https://www.google.com/&httpsredir=1&article=1634&context=etd
(Bottom of page) Links to additional raptor, human, other wildlife studies: https://www.nps.gov/pinn/learn/nature/leadinfo.htm
Wild Meat Raises Lead Exposure: https://www.scientificamerican.com/article/wild-game-deer-venison-condors-meat-lead-ammunition-ban/
Thanks Caitlyn, I did not realize this is an issue. It makes a lot of sense though. Having hunted my whole life and left lots of gut piles in the woods, I wonder, along w Lloyd, what the repercussions are with the animals that he mentioned and even opossums and buzzards. I often have seen those feasting on the leftovers.
This kind of makes bow hunting a little more environmental for all animials. I will think about copper bullets now.thanks
Caitlyn, Appreciated the article.
Some common sense, little effort remedies were offered that I think would or could be well received by general hunting population with a round of education. ( i.e. in Pennsylvania a Hunter / Trapper Educational course would be appropriate forum )
A follow up question?? Do you have any data on lead levels in higher food chain predators such as fox, coyote, bears ??
Just a thought. Lloyd
Great information and tone in this article and it is important to be having this conversation. I'm hearing more and more about lead in the environment after there had been a decline for many years.
Thank you!
Your comment has been received. Before it can be published, the comment will be reviewed by our team to ensure it adheres with our rules of engagement.
Comments
I love this its amazing
Humans are potentially at risk. The harm to eagles is current, documented and lethal, but eagles are by no means the only beings affected. Due to their particular biological makeup, eagles and other raptors become terminally poisoned at low doses, making it an acute situation. Humans do not show the same immediate and devastating symptoms, but lead levels are shown to be much higher in those consuming game meat—particularly ground burger game. There is also the concern that, for humans, small amounts of lead over time can do more harm than a large amount at once.
The "What you can do" section of the article discusses the exposure of humans to lead levels in game meat and link to an article about human ingestion. In this Iowa investigation, it was found that some samples of deer meat showed lead levels up to 194 times higher than the threshold set by European Food Safety Agency for lead levels in meat. It went on to disclose that the state was not looking at game meat as a source of lead for the community, and quoted University of Colorado medical professor Michael Kosnett as stating "You lose more I.Q. points at low levels of exposure, per increment of blood lead, than you do at higher levels."
The "How is lead entering the system?" section links to an article in Scientific American about the amount of lead present in wild meat. This article quotes Dr. William Cornatzer, a hunter, on his reaction to seeing evidence of lead poisoning in condors and the immediate link he made to the lead he and his family would have ingested, saying, "I knew good and well after seeing that image that I had been eating a lot of lead fragments over the years."
Hunting helps to stabilize the deer population, creates revenue for conservation and stewards of the environment through hunters, and provides an excellent source of lean meat—though as we all discover new information about unintended consequences and harms, such as the findings on lead fragmentation, we can continually update our practices for the good of both humans and wildlife.
Iowa investigation of human lead levels from game meat: http://www.kwqc.com/content/news/TV-6-Investigates-Lead-in-venion-Iowa-health-officials-actions-421225163.html
Scientific American article on lead exposure from wild meat consumption: https://www.scientificamerican.com/article/wild-game-deer-venison-condors-meat-lead-ammunition-ban/
I am wondering why I see articles like this on the potential harm to eagles from lead ammunition, but I have never seen an article about potential harm to humans. It only seems logical that if raptors are poisoned by lead ammunition wouldn’t humans be also ?
I suppose my ultimate concern is without stating clearly that lead poisoning is an insignificant, mortality factor for raptor populations, the general, human population can easily be led to believe deer hunters are wantonly killing birds of prey. A simple Google search for "lead poisoning, eagles" brings up articles by National Geographic, The Washington Post, and The Guardian on the matter. That being said, I will now hunt with copper bullets for deer; I just wish more coverage was devoted to plummeting small, game populations which coincidentally, are prey for raptors.
Great question, Vince! Connecting landscapes to provide habitat is imperative to having a healthy watershed. The Bay Program's Vital Habitats Goal Implementation Team, along with its partners, is dedicated to restoring a network of habitats for vital species. You can read more about the Vital Habitats Team in this highlight article: https://www.chesapeakebay.net/news/blog/by_supporting_key_habitats_we_support_the_ecosystem.
Lead poisoning is not a significant mortality factor for the eagle population, but it is a completely preventable and painful death for those that are affected. The implications of lead contamination extend to humans, who are also ingesting lead fragments in venison: https://www.scientificamerican.com/article/wild-game-deer-venison-condors-meat-lead-ammunition-ban/.
I like the thoughtfulness and balance of this article. My only question, however, is lead poisoning a significant stressor/mortality factor for the entire population? With raptor's amazing comeback in response to federal protections and rapidly declining small game populations, is lead poisoning in a small portion of raptors truly a cause for concern when populations for these birds of prey are literally soaring? As a hunter, I would like to see more attention paid to fragmented landscapes and reduced habitat for small game as these animals don't have federal protections such as eagles, hawks, and falcons.
Eagles are often highlighted for this issue as our national bird, but most avian scavengers (vultures, ravens, condors out west) also experience these high lead levels. In New England, the leading cause of loon death is lead poisoning—in this case, from lead tackle rather than ammunition. Birds are extremely susceptible to lead, and the damage is extensive.
I found only a single study addressing large carnivores. Possibly because their diets are more varied, they are larger, and they have different biological symptoms, they are not as susceptible as our birds. Humans, too, ingest lead in venison, but the effects are not as immediately apparent as they are with birds. Grizzlies had higher lead levels, but the cause is still unknown because it did not change with the hunting seasons.
As for secondary ingestion, lead is eventually stored in the bones of an animal. If a large predator were eating the bones of a lead-contaminated smaller animal (not usually the case), the predator's lead levels would undoubtedly be much higher. Biological magnification (levels being higher in an animal that eats multiple contaminated animals) does not seem to be occurring with lead toxicity, though there was little research available for wildlife outside of birds on the topic of lead.
Ravens: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4229082/#pone.0111546-Gordon1
Loons: http://www.audubon.org/news/toxic-fishing-tackle-hampering-loon-recovery-new-hampshire
Large carnivore study: https://scholarworks.umt.edu/cgi/viewcontent.cgi?referer=https://www.google.com/&httpsredir=1&article=1634&context=etd
(Bottom of page) Links to additional raptor, human, other wildlife studies: https://www.nps.gov/pinn/learn/nature/leadinfo.htm
Wild Meat Raises Lead Exposure: https://www.scientificamerican.com/article/wild-game-deer-venison-condors-meat-lead-ammunition-ban/
Thanks Caitlyn, I did not realize this is an issue. It makes a lot of sense though. Having hunted my whole life and left lots of gut piles in the woods, I wonder, along w Lloyd, what the repercussions are with the animals that he mentioned and even opossums and buzzards. I often have seen those feasting on the leftovers.
This kind of makes bow hunting a little more environmental for all animials. I will think about copper bullets now.thanks
Caitlyn, Appreciated the article.
Some common sense, little effort remedies were offered that I think would or could be well received by general hunting population with a round of education. ( i.e. in Pennsylvania a Hunter / Trapper Educational course would be appropriate forum )
A follow up question?? Do you have any data on lead levels in higher food chain predators such as fox, coyote, bears ??
Just a thought. Lloyd
Great information and tone in this article and it is important to be having this conversation. I'm hearing more and more about lead in the environment after there had been a decline for many years.
Thank you!
Your comment has been received. Before it can be published, the comment will be reviewed by our team to ensure it adheres with our rules of engagement.
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