NRA Renews Attack On Science Proving That Lead Ammunition Is Bad For Wildlife

Huffington Post: NRA Launches Revamped “Hunt For Truth” Website On August 2 To Promote New Effort “To Block Attempts To Regulate The Use Of Lead In Bullets.” The Huffington Post identified Hunt for Truth as an NRA affiliate in an August 5 article:

In a move bizarrely reminiscent of its “anti-gun” enemies list, the National Rifle Association announced a new plan Friday to target scientists, environmental groups, government regulators and individuals who favor banning the use of lead in gun ammunition.

The targeted attacks are part of Hunt for Truth.org, a newly revamped effort by the nation's largest gun lobby to block attempts to regulate the use of lead in bullets. Regulations have been proposed in some states after studies have shown that millions of birds -- most notably the highly endangered California condor -- are dying of lead poisoning after ingesting lead bullet fragments.

The Center for Biological Diversity, an environmental group, estimates that hunters in the United States shoot more than 3,000 tons of lead into the outdoors every year, and that as many as 20 million birds die annually from lead poisoning.

To the NRA, however, the proposed bans on lead in bullets represent an “assault” on “traditional” hunting and on hunters' rights.

“Anti-lead ammunition groups will not rest until all lead ammunition, and ultimately hunting, is banned,” the gun lobby claimed in a Friday press release. [Huffington Post, 8/5/13]

NRA Institute For Legislative Action Press Release: Hunt For Truth Website Updated “To Educate And Assist” Policymakers And Public “About The Efforts To Ban Lead Ammunition Nationwide.” [NRA-ILA, 8/2/13]

Hunt For Truth Website And NRA's Press Release Pulled By August 8

Hunt For Truth Website “Is Undergoing Scheduled Maintenance.”

[Hunt for Truth, accessed 8/8/13]

NRA Press Release Announcing Hunt For Truth No Longer On NRA-ILA Website. 

[NRA-ILA, accessed 8/8/13]

The Lead Used In Ammunition Poisons Wildlife

NRA CLAIM: The Lead In Ammunition Is Not Dangerous To Wildlife

• Hunt for Truth claims that special physical properties of the metallic lead in ammunition make it “highly resistant to corrosion” and therefore not dangerous to wildlife. [Hunt for Truth, accessed 8/7/13]
• On NRA News, NRA board member Don Saba claimed “the lead that's in ammunition is fairly non-toxic.” [The Sportsman Channel, Cam & Company, 5/7/13]

• Hunt For Truth claims that the science showing lead ammunition harms wildlife is “riddled with false assumptions, faulty methodology, selective presentation of data and outright ignoring of plausible alternative explanations.” [Hunt for Truth, accessed 8/7/13] 

Scientific Review: 59 Bird Species Have Been “Documented To Have Ingested Lead Or Suffered Lead Poisoning From Ammunition Sources.” A 2006 “review of lead poisoning from ammunition sources in terrestrial birds” found that 59 terrestrial bird species have been documented to have ingested or been poisoned by lead from ammunition sources, including threatened species. The review noted that, contrary to claims that lead from ammunition cannot poison wildlife because of its resistance to corrosion, the stomachs of raptors are highly acidic and dissolve it “rapidly”:

Fifty-nine terrestrial bird species have so far been documented to have ingested lead or suffered lead poisoning from ammunition sources, including nine Globally Threatened or Near Threatened species. We discuss the conservation significance of continued lead use, and detail measures needed to combat lead poisoning.

[...]

One of the main groups to be affected by ingestion of lead shot and poisoning is raptors (Miller et al., 2002). Lead is rapidly dissolved by the low pH in raptor stomachs, and subsequently absorbed. When large amounts of lead are rapidly absorbed, illness and death can be sudden, and birds may die in apparently good physical condition (Gill and Langelier, 1994). [Biological Conservation, 2/28/06, via Hunting With Non-Lead Ammunition]

Scientific Review: Lead Ammunition Causes “A Range Of Effects” In Animals Including “Population-Level Consequences In Some Species.” A review of scientific research on lead ammunition by wildlife experts at the Wildlife Society and American Fisheries Society found that while lead ammunition can be “relatively stable” under some circumstances that under others it is poisonous to a broad spectrum of wildlife:

[L]ead from spent ammunition and lost fishing tackle is not readily released into aquatic and terrestrial systems. Lead artifacts can be relatively stable and intact for decades to centuries. Nevertheless, under some environmental conditions (e.g., soft acidic water, acidic soil), lead can weather and be mobilized from such artifacts, yielding free dissolved lead, precipitates, and complex species with inorganic and organic matter. Dissolved, complex species and particulate lead can be adsorbed onto or incorporated into the surface of plants. In soil and sediment, various forms of lead can become adsorbed, taken up by tissues, and entrained in the digestive tract of invertebrates.

[...]

There is evidence documenting ingestion of spent shot and bullets, lost fishing sinkers and tackle, and related fragments by reptiles, birds, and mammals. Ingestion of some of these elemental lead artifacts can be accompanied by a range of effects (molecular to behavioral) in individuals and potentially even population-level consequences in some species (e.g., waterfowl, eagles, condors). [The Wildlife Society and American Fisheries Society, June 2008]

Study: Exposure To Metallic Lead Linked To Death Or Poisoning For Andean Condors. A study dosed four Andean condors “with lead shot and found them to be quite sensitive, as two of the birds died and the other two exhibit signs of lead poisoning within 50 days,” noting this “is consistent with observations in the wild, where otherwise healthy birds exposed to metallic lead quickly succumb”: 

Elevated lead in the tissues of raptors, especially those that scavenge, is a common occurrence, and lead poisoning appears to be a significant problem in the ongoing recovery effort for California condors (Gymnogyps californianus). Elevated blood lead levels have been found in released birds, and a number of birds have died of lead poisoning. In earlier work, we dosed turkey vultures (Cathartes aura) with lead shot but found them to be a poor model for lead poisoning. In this study, we dosed four Andean condors (Vultur gryphus) with lead shot and found them to be quite sensitive, as two of the birds died and the other two exhibit signs of lead poisoning within 50 days. All lead-responsive parameters were affected, and regurgitation of dosed shot occurred only once. The response of the Andean condors appeared to mimic California condors, suggesting that once exposed to lead, the possibility of survival is poor. This is consistent with observations in the wild, where otherwise healthy birds exposed to metallic lead quickly succumb. At the very least, the release program has to maintain constant surveillance and an active lead monitoring program. [Journal of Wildlife Diseases, 2006, emphasis added]

30 Environmental Health Scientists: “The Discharge Of Lead-Based Ammunition ... Poses Significant Health Risks To Humans And Wildlife.” A March 22 statement published by 30 scientists from universities, hospitals, and wildlife research groups explained “the overwhelming scientific evidence on the toxic effects of lead on human and wildlife health”:

3) The discharge of lead-based ammunition and accumulation of spent lead-based ammunition in the environment poses significant health risks to humans and wildlife. The best available scientific evidence demonstrates:

a) The discharge of lead-based ammunition substantially increases environmental lead levels, especially in areas of concentrated shooting activity (USEPA ISA for Lead draft report, 2012).

b) The discharge of lead-based ammunition is known to pose risks of elevated lead exposure to gun users (NRC, 2012).

c) Lead-based bullets used to shoot wildlife can fragment into hundreds of small pieces, with a large proportion being sufficiently small to be easily ingested by scavenging animals or incorporated into processed meat for human consumption (Pauli and Burkirk, 2007; Hunt et al., 2009; Knott et al., 2010).

d) Lead-based ammunition is a significant source of lead exposure in humans that ingest wild game (Hanning et al., 2003; Levesque et al., 2003; Johansen et al., 2006; Tsuji et al., 2008), and hunters consuming meat shot with lead-based ammunition have been shown to have lead pellets/fragments in their gastrointestinal tract (Carey, 1977; Reddy, 1985).

e) Lead poisoning from ingestion of spent lead-based ammunition fragments poses a serious and significant threat to California wildlife.

i. Spent lead-based ammunition is the principal source of lead exposure to the endangered California condor, and lead poisoning in condors is preventing their successful recovery in the wild (Church et al., 2006; Woods et al., 2007; Green et al., 2008; Parish et al., 2009; Rideout et al., 2012; Finkelstein et al., 2012).

ii. Many other wild scavenging species, such as golden eagles, bald eagles, ravens, turkey vultures, and pumas are known to be exposed to and affected by lead (Wayland and Bollinger, 1999; Clark and Scheuhammer, 2003; Fisher et al., 2006; Craighead and Bedrosian, 2008; Stauber et al., 2010; Kelly and Johnson, 2011; Burco et al., 2012). [A Consensus Statement of Scientists, 3/22/13] 

Scientists Believe “Lead-Based Ammunition Is Likely The Greatest Largely Unregulated Source Of Lead That is Knowingly Discharged Into The Environment In The United States.” A letter signed by 15 scientists, all of whom signed the March letter on the dangers of lead to humans and wildlife, noted that while other sources of environmental lead contamination are highly regulated, there are few regulations on the release of lead ammunition into the environment:

Notably, production of lead-based ammunition in the United States accounted for > 69,000 metric tons consumed in 2012; this is second only to the amount of lead used to manufacture storage batteries (U.S. Geological Survey 2013). However, there are few regulations regarding the release of lead into the environment through discharge of lead-based ammunition. For other major categories of lead consumption, such as lead batteries and sheet lead/lead pipes, environmental discharge and disposal are regulated. Therefore, leadbased ammunition is likely the greatest largely unregulated source of lead that is knowingly discharged into the environment in the United States. In contrast, the release or distribution of other major sources of environmental lead contamination (e.g., leaded gasoline, lead-based paint, lead solder) have been substantially regulated and reduced since the mid-1970s (Health Risks from Lead-Based Ammunition in the Environment--A Consensus Statement of Scientists 2013). [Environmental Health Perspectives, June 2013]

Banning Lead Ammunition Would Allow Hunting To Continue

NRA CLAIM: Banning Lead Ammunition Would Ban Hunting

• The NRA claimed that the real “agenda” of opponents of lead ammunition was to ban hunting, saying they “will not rest until all lead ammunition, and ultimately hunting, is banned.” [NRA-ILA, 8/2/13]
• On NRA News' Cam & Company, host Cam Edwards claimed that the ultimate goal of proponents of lead ammunition bans is “to put an end to hunting in this country.” [The Sportsman Channel, Cam & Company, 5/8/13] 

Hunting Continues In California Condor Range Where Lead Restrictions Are In Place. In 2007, California enacted legislation to restrict the use of lead ammunition in California condor ranges that also sought to provide hunters with non-lead alternatives:

In October of 2007, California Gov. Arnold Schwarzenegger signed into law Assembly Bill 821 which banned the use of lead ammunition from areas of the state inhabited by the California Condor, a federal endangered species. The signing marked a great victory for Audubon California and other organizations that had fought for years to remove the toxic substance from the Condors' environment.

Condors frequently feed on animal carcasses left behind by hunters, and ingest dangerously high levels of lead from ammunition. In the last 10 years, it is estimated that roughly 30 Condors have died from lead poisoning in this manner.

The new law was authored by Assemblyman Pedro Nava, and will require the use of non-lead centerfire ammunition within the Department of Fish and Game's deer hunting zones within current and potential condor range in California beginning July 1, 2008. Lead-free ammunition is increasingly available and it is expected to have no effect on hunters' enjoyment of their sport. To the extent funding is available, big game hunters in these hunting zones will get coupons for non-lead ammunition at no or reduced charge. [Audubon California, accessed 8/7/13]

Proposed California Statewide Ban On Lead Ammunition Seeks To Provide Hunters With Lead-Free Ammunition At No Or Reduced Charge. From A.B. 711, the California legislation that proposes to make the ban on lead ammunition statewide:

(c) (1) To the extent that funding is available, the commission shall establish a process that will provide hunters with nonlead ammunition at no or reduced charge. The process shall provide that the offer for nonlead ammunition at no or reduced charge may be redeemed through a coupon sent to a permitholder with the appropriate permit tag. If available funding is not sufficient to provide nonlead ammunition at no charge, the commission shall set the value of the reduced charge coupon at the maximum value possible through available funding, up to the average cost within this state for nonlead ammunition, as determined by the commission. [A.B. 711, accessed 8/7/13]

Lead From Ammunition Poisons California Condors

NRA CLAIM: Lead Ammunition Is Not Contributing To The Decline In California Condors 

• Hunt for Truth states that “hunters' ammunition is not the cause of lead exposure and toxicity in condors and alternative sources of lead are to blame.” [Hunt for Truth, accessed 8/7/13]
• On the NRA News' Cam & Company, host Cam Edwards claimed that “lead ammunition is a very unlikely cause of the alleged poisoning of California condors.” [The Sportsman Channel, Cam & Company, 5/6/13]

Study: The “Most Prominent Mortality Factor” In California Condors In The 1980s Was “Lead Poisoning Resulting From Ingestion Of Bullet Fragments.” From the peer-reviewed scientific journal Conservation Biology:

The remnant wild population of California Condors (Gymnogyps californianus) of the 1980s exhibited a rapid population decline caused by high mortality rates among adult and immature birds. The most prominent mortality factor was lead poisoning resulting from ingestion of bullet fragments in carcasses.

[...]

Lead poisoning again surfaced as a problem starting in 1997 as older birds began feeding on carcasses outside the subsidy program. Although poisonings have been treated successfully by chelation therapy [a method of drawing heavy metals out of the body] in recaptured birds, food subsidy is proving an ineffective solution to lead exposure. The best long-term solution appears to be either the creation of large reserves where hunting is prohibited or the restriction of hunting to nontoxic ammunition in release areas. Until sources of lead contamination are effectively countered, releases cannot be expected to result in viable populations.

[...]

We consider lead poisoning a more important cause of mortality than collisions, both historically and for the future for several reasons. First, the nearly equal mortality rates of immature and adult condors in the original wild population seem better explained by lead poisoning than by collisions. Ingestion of lead in carcasses may be equally likely in adults and immature birds, whereas collisions are often more frequent in immature birds than adults in large avian species (e.g., Leshem 1985; Hunt 1997). Second, the frequency of lead poisoning in releases presumably would have been much higher in the absence of food subsidy, even though food subsidy has been less than effective in reducing lead poisoning. [Conservation Biology, August 2000]

Arizona Game And Fish Department:  Lead Ammunition Is “The Major Source Of Lead In Condors.” Research by the Arizona Game And Fish Department determined that at least 15 condors have died from lead poisoning since 2000, that 45 to 95 percent of the condor population tests positive for lead exposure each year, and that lead exposure rates are highest during the fall hunting season:

Lead toxicity has been identified as the leading cause of death in condors in the Arizona reintroduction program. At least fifteen condors have died of lead poisoning since 2000. Condors are trapped twice a year to have their blood tested for lead. Biologists have documented over 300 instances of lead exposure in condors since testing began in 1999, with 45 to 95 percent of the condor population testing positive for lead exposure each year. Chelation treatment is often required to reverse dangerously high blood lead levels. Surgery has also been needed in the worst cases. Without these treatments more condors likely would have died.

Although there may be other sources of lead, a scientific study funded by the Arizona Game and Fish Department has identified lead from spent ammunition as the major source of lead in condors. Background lead from the environment does not appear to be a factor. An additional study has determined that condor lead exposure rates are highest during the fall hunting season in northern Arizona. This study also concluded that during this same time, condors spend forage heavily on the Kaibab Plateau. The Arizona Game and Fish Department is committed to reducing the amount of lead available to condors by encouraging sportsmen to take lead reduction actions when hunting in condor range. [Arizona Game and Fish Department, accessed 8/7/13, emphasis added]

Statement Of Scientific Agreement: “Analysis Of Lead In The Blood Of Pre-Release And Free-Flying Condors In California Strongly Supports The Link Between Lead Ammunition And Lead Exposure.” From a 2007 letter signed by 44 academic scientists, biologists, and activists in support of lead ammunition restrictions in California condor habitats that concluded "[l]ead ammunition is, therefore, the principal, and only plausible, documented source of lead exposure in condors":

Isotopic analysis of lead in the blood of pre-release and free-flying condors in California strongly supports the link between lead ammunition and lead exposure. Lead isotope ratios have been used for over 25 years to trace source(s) of environmental lead exposure. The use of lead isotope ratios for evaluating lead exposure is based on the natural existence of lead in four stable isotopes. The natural relative abundances of these isotopes often varies across different lead-containing industrial products (e.g., leaded paint or ammunition) because lead used in making those products comes from different sources of lead. Lead isotopic ratios in lead-exposed animals are like fingerprints that can be traced back to a particular source of lead exposure. Indeed, lead isotopes offer the most accurate way to trace the sources of elevated lead exposures, and they have been used to trace the sources and pathways of lead exposure in humans, as well as in wildlife such as California condors.

Church et al. (2006) evaluated the sources of elevated lead exposure in California condors based on: (i) knowledge of the plausible sources of lead exposure to the condor, including lead concentrations; (ii) the quantified isotopic ratios of those plausible lead sources within that environment; and, (iii) information about behavioral habits, as well as an evaluation of viable pathways of exposure to the organism. This study clearly shows that pre-release condors have an isotopic signature that is significantly different from lead in free-flying condors in central California, whereas the blood lead isotopic signature of the majority of free-flying condors approached or matched the isotopic signature of lead ammunition collected from the condors' central California range. Lead ammunition is, therefore, the principal, and only plausible, documented source of lead exposure in condors. The Church et al. (2006) study underwent rigorous scientific peer review in the publication process for Environmental Science and Technology. This publication is an American Chemical Society journal and one of the top-ranked scientific journals in the areas of environmental chemistry and environmental toxicology. [Statement of Scientific Agreement, 7/10/07, emphasis original]

Turkey Vulture Study Did Not Disprove Ammunition-Lead Poisoning Link

NRA CLAIM: Research Has Demonstrated “The Low Solubility Of Metallic Lead In Avian Scavenger's Digestive System.” Hunt for Truth claims that a 2003 study published in the Journal of Wildlife Diseases disproves the danger of lead ammunition to avian scavengers because, “Turkey vultures were continually fed lead shot for over 140 days before finally succumbing to lead toxicosis, demonstrating the low solubility of metallic lead in avian scavenger's digestive system.” [Hunt for Truth, accessed 8/7/13, page since deleted and not available in archive]

Authors Of Study Concluded That Turkey Vultures Were Not A Good Substitute For California Condors In Lead Studies And Their Findings Could Not Apply Generally To All Avian Scavengers. The authors concluded that “considerable tolerance by turkey vultures to the deleterious effects of lead ingestion” meant that “turkey vultures appear to be poor models for assessing the risk of lead poisoning to California condors or predicting their physiologic response.” Like other scientific research, the study noted that "[t]he probable source of lead ingested by California condors was bullets and bullet fragments in the carrion consumed by the birds," and that during the 1980s, lead poisoning was responsible for 20 to 25 percent of California condor fatalities:

Lead-induced mortality appears to have been a major factor in the decline of the California condor (Gymnogyps californianus). We orally dosed turkey vultures (Cathartes aura) with BB-sized lead shot from January 1988 through July 1988 to determine physiologic response (delta-aminolevulinic acid dehydratase inhibition, erythrocyte protoporphyrin levels, anemia), diagnostic tissue lead concentrations (blood, liver, and kidney), and comparative sensitivity of this species. Two turkey vultures died and two became so intoxicated they were euthanized. Overall, responses of measured parameters were comparable to other species exposed to lead although there was considerable individual variation. Survival time (143-211 days), even with the large numbers of shot and constant redosing, was much longer than reported for other species of birds, suggesting considerable tolerance by turkey vultures to the deleterious effects of lead ingestion. Based on these observations, turkey vultures appear to be poor models for assessing the risk of lead poisoning to California condors or predicting their physiologic response.

[...]

Lead poisoning gained attention as a potentially significant factor for California condors during the 1970s and 1980s. A California condor that died in 1975 had elevated concentrations of lead in its bones (Wiemeyer et al., 1983). During the 1980s, lead poisoning was the cause of death in three of the five confirmed mortalities (Wiemeyer et al., 1988) and constituted 20-25% of all losses (Snyder, 1986). The probable source of the lead ingested by California condors was bullets and bullet fragments in the carrion consumed by the birds. [Journal of Wildlife Diseases, 2003]

Bald And Golden Eagles Have Elevated Lead Levels Because Of Ammunition

NRA CLAIM: Lead Sources Other Than Ammunition Responsible For Lead Poisoning In Bald And Golden Eagles. From Hunt for Truth's website:

Environmental activists and researchers claim that bald eagles are increasingly being poisoned by ingesting lead shot in carrion of waterfowl and upland game left in the field by hunters. These same environmental activists and researchers again ignore alternatives sources of lead in the environment, other causes on death that are summarily blamed on lead poisoning and the fact that bald eagle population levels are soaring.

[...]

Like the bald eagle, environmental activists and researchers claim that golden eagles are being poisoned by hunters' lead ammunition in carrion left in the field. [Hunt for Truth, accessed 8/7/13]

Study: Eagle Lead Poisoning Directly Associated With Hunting Season. A peer-reviewed study appearing in PLOS ONE noted that "[a] spatial-temporal association with lead exposure and big game hunting seasons has been found for both bald and golden eagles in California, the Pacific Northwest, and the Midwest." According to the study, lead poisoning is responsible for the deaths of some eagles, although tolerance varies among individuals:

We tested 81 blood samples from bald eagles before, during and after the big game hunting seasons in 2005-2010, excluding 2008, and found eagles had significantly higher lead levels during the hunt. We found 24% of eagles tested had levels indicating at least clinical exposure (>60 ug/dL) during the hunt while no birds did during the non-hunting seasons.

[...]

During the 2009 and 2010 hunting seasons we provided non-lead rifle ammunition to local hunters and recorded that 24% and 31% of successful hunters used non-lead ammunition, respectively. We found the use of non-lead ammunition significantly reduced lead exposure in eagles, suggesting this is a viable solution to reduce lead exposure in eagles.

[...]

While several eagles have been found dead with confirmed lead poisoning (liver lead concentrations >6 ppm ww) during the hunting season within our study area (S. Patla pers. comm.), it appears there is large variation among individuals in the amount of lead that can be tolerated. [PLOS ONE, 12/19/12]