Impacts of Lead Ammunition on Wildlife, Humans, and the Environment

Molly Tranel

MNDNR

MACP Contaminants and Natural Resource Management Workshop

History of Lead Ammunition in USA

1870s: Large waterfowl die-offs; Discovered

pheasant mortality from lead shot ingestion

1940’s: Reports >16,000 ducks die

1980’s: Bald eagles in MN poisoned from

lead shot , MN bans use of lead shot for

waterfowl hunting

1991: Federal ban on lead shot for

waterfowl hunting

1999: Ban on lead shot for any hunting on

federal Waterfowl Production Areas

Literature Review Findings

Considerable research exists on the

impacts of lead ammunition- >500 scientific articles

Lead ammunition negatively affects wildlife- >130 species reported worldwide

Lead ammunition can impact human health- Elevated lead blood levels from game consumption

Nontoxic alternatives are now available- Gun Digest Book of Green Shooting

Number of Species Affected by Lead

Ammunition

Passerines

8

Reptiles

2

Mammals

6

Upland

Gamebirds

16

Other Waterbirds

18

Raptors &

Scavengers

31

Waterfowl

51

132 Species

(Tranel & Kimmel, 2009)

Ways Wildlife Ingest Lead

1. Mistake Lead Shot

for Grit.

2. Incidentally Ingest

Lead While Feeding

3. Secondarily Ingest

Lead Through Prey

How are birds affected by lead?

Decreased survival

-Poor body condition

-Weakened muscles

-Reduced weight & starvation

Reduced immune systems

More vulnerable to disease

& parasites

Impaired reproduction

Behavioral changes

How many birds are affected?

Depends on how heavily

hunted an area is.

Numbers may be

underestimated because

birds expel shot

Sick or dead birds are hard to find

They hide when dying

Predators eat them

Species % >10 μg/g bone lead Year Sampled

Hungarian

Partridge 11 (19/169) 2001

Sharp-tailed

Grouse 5 (4/79) 2001

Mallard *8 (17/214) 1989/90

*This level was high enough to prompt a ban on

lead shot for waterfowl hunting.

Percent of upland game birds & ducks

from Canada, with elevated

(>10 μg/g) bone lead.

Percent of upland game birds that

ingested shot.

Species % ingesting shot Year Sampled

Northern Bobwhite 1.3 2002

Ruffed Grouse 1.2 2005

Pheasant 3 (G. Britain) 2005

34 (Canada) 2007

Chukar 8 2007

Doves Ingesting Shot

Acute toxicosis hypothesis: Evidence

suggests doves purposefully ingest

Pb pellets, and succumb to acute

effects of Pb on the circulatory/

central nervous systems.

Conducted two experiments to test hypothesis:

(1) force-fed doves Pb pellets, and monitored survival

and physiological characteristics, and

(2) provided Pb and steel pellets ad lib. and monitored

relationship between pellet availability and selection.

Doves Ingesting Shot Results show doves

purposefully ingest Pb pellets,

and succumb to the acute

effects of Pb.

Survival rates (0.57–0.08) with

≤2–19 ingested Pb pellets show

that even at low doses birds are

dying rapidly.

Although some survived the

post-treatment period, those

individuals would have likely

died in the wild due to

secondary causes of mortality

(Schulz et al. 2006a). 11

treatment

control

Background

Example: J.A. Reed Area September 2005

1,425 hunters reported ~40,000 rounds fired

185 acres of managed sunflower/wheat

2,500 lbs. of lead 13.5 lbs. of lead / acre

75,000 pellets / acre ~2 Pb pellets per ft2

Tennessee:

1.2% hunter-killed doves ingested Pb pellets; some

w/ 24 Pb pellets.

New Mexico:

3.5% hunter-killed doves ingested Pb pellets

USGS 8 state survey

2.5% hunter-killed doves ingested Pb pellets

Pellets per dove ranged 1–43; 3.8% of doves

ingesting ≥15 pellets

Doves Ingesting Shot

Pellet ingestion rate (5.1%)

was within the range

previously reported from

hunter-killed doves (2.0% –

6.5%)

Data also show that when

pellets are available, some

proportion of mourning

doves will ingest pellets,

and those doves ingesting

pellets will eventually die.

Discussion THE FOLLOWING EXAMPLE IS ONLY

FOR DEMONSTRATION PURPOSES TO SHOW THE POTENTIAL MAGNITUDE OF THE PROBLEM.

Given a 350–475 million fall population (Dunks et al. 1982, Otis et al. 2008), we can “roughly” estimate that 18–24 milliondoves may be dying annually in North America from Pb toxicosis.

(ingestion rate x population = dead doves)

(0.05 x 350 million = 17.50 million)

(0.05 x 475 million = 23.75 million)

(Note that the 2006 HIP dove harvest was estimated to be 18.3 – 20.2 million).

Other Pb Research:

Crippling Rates & Nontoxic Shot

Debate will likely include speculation about nontoxic shot resulting in increased crippling loss of mourning doves.

Evaluated waterfowl crippling rates prior to, during, and after nontoxic regulations implementation, and made inferences about mourning dove crippling rates if further nontoxic shot regulations are enacted.

These data suggest long-term mourning dove crippling rates might not increase as evidenced from historical waterfowl data.

16

Pre-nontoxic shot Phase-in Nontoxic shot

Period

0.130

0.140

0.150

0.160

0.170

0.180

0.190

0.200

95

% C

I of

Mo

vin

g A

vera

ge C

rip

pli

ng

Rate

s

Ducks

Pre-nontoxic shot Phase-in Nontoxic shot

Period

0.110

0.120

0.130

0.140

0.150

95%

CI

Movin

g A

vera

ge C

rippli

ng R

ate

s

Geese

Human Health Impacts

Consumption of game birds linked to

elevated blood lead levels in adults, children,

and newborns Greenland1, Russia2, Canada3

Lead fragments from bullets found in

venison. MN4

Food sources can become contaminated in

heavily hunted areas.

1Johansen et al. 2004, 2006; 2 Odland et al. 1999; 3 Dewaily

et al. 2000, 2001; 4Grund et al. 2009

Impacts of Lead on Humans

Children absorb lead at a faster

rate and are more sensitive to it.

Pregnant women can transfer

lead to the fetus.

Low level lead exposure linked to:

- Lower IQ – cognitive function

- Behavioral problems – aggression,

depression, ADD, and ADHD

- High blood pressure, memory loss

later in life

Canfield R, et al. 2004. NEJM 348: 1517-1526.

IQ and Blood Lead

2009 US CDC

level for

intervention in

children

Slide courtesy of

Michael Kosnett,

CDC Childhood

Lead Prevention

Committee

(Image courtesy of the Minnesota Dept of Natural Resources)

Radiograph of

the chest of a

deer-sized

animal

illustrating

lead

fragmentation

of a ballistic

tip rifle bullet.

The North Dakota CDC study[Iqbal, 2008]

Participants consumed game in the form of

venison, other game, and birds.

Consumption of wild game was significantly

associated with lead blood levels.

Participants who consumed wild game had

higher lead levels than those who did not

consume wild game.

All participants were below the CDC level of

concern (10mg/dL).

Reducing your risk of lead exposure

If you hunt with lead, there’s some lead

in the meat

The only way to completely eliminate lead is

to use nontoxic shot / bullets

Avoid using rapid expansion bullets

Choose wise shots

Cut liberally around wound channel

Do not consume internal organs

Conclusion: Certainties

Pb is a well established ecological

poison, and there no “safe” level

of ingestion.

Hunters deposit large amounts of

Pb shot on popular dove feeding

sites, a certain proportion of

doves feed on these sites and

ingest pellets, and die.

Any animal shot with Pb-based

ammunition likely will contain

some amount of Pb residue in the

meat.

Conclusion: Uncertainties

Relationship between pellet ingestion

and pellet availability on areas with

different levels of hunter and bird use.

Proportion of the population impacted

by Pb poisoning, and whether that

proportion is significant.

Population impacts to other species of

surface-feeding seed-eating songbirds

and upland game-birds.

Impacts of nontoxic ammunition

regulations on hunter recruitment and

retention, and impacts on ammunition

industry

“Hunters have a reputation as being

good conservationists, if we don‟t do

something about the lead issue we

could lose that reputation.”

- Board Member of the New Ulm Chapter

Isaac Walton League

Hunter Education the next step?

Several states (CA, AZ, IA,

WY) are including lead ammo

in hunter education and safety

courses.

Providing information on types,

where to buy non-toxic ammo,

and even free ammo.

Getting the word

out when new

non-toxic ammo

or tackle is

available.

AZ Game and Fish Hunter Survey

Only 23% of the hunters were aware

that lead poisoning was a problem

faced by condors

83-97% were willing to take some

action to help condors if credible lead

exposure data were made available.

Hunters expressed a greater

willingness to help if asked by a

credible source like sportsmen’s

groups & the state wildlife agency.

(D. J. Case and Associates 2005)

85% of hunters

in condor range

voluntarily use

non-lead

Hunter Survey

81% surveyed used the free non-

lead ammunition during their hunts.

97% of respondents who tested the

non-lead ammunition (n = 796)

stated its accuracy was average to

excellent.

56% indicated they would purchase

it on their own in the future.

72% said they would recommend

non- lead ammunition to other

hunters.

The „Green Ammo‟ future

“Green shooting is growing at a rate of about

20% a year…”

“Government agencies and even the Dept. of

Defense are switching to lead-free shooting…It

just makes range operation so much easier and

training so much more practical and effective.”

“…concerns about the environment, and the

need for effective training scenarios are

going to drive the green and frangible

bullet movement much larger.”

(excerpts from Sapp 2010)

Special Thanks

Jon Schulz for providing slides and information.

Dick Kimmel, MN DNR

Questions?

Cartoon by Nick D Kim, nearingzero.net