The Science of Lead

1. The Science of Lead WAFWA Ad Hoc Lead Working Group May 7, 2010 Portland, OR Kristin Mansfield, WDFW Lloyd Fox, KDWP

2. Sources and Implications of Lead Ammunition and Fishing Tackle on Natural Resources TWS and ASF Technical Review, June 2008

3. Table of Contents * Introduction * Sources and estimated quantities of Lead from Hunting, Shooting Sports, and Fishing Activities * Biogeochemistry and Physiochemical Properties of Lead * Pathways of Exposure to Lead from Hunting, Shooting Sports, and Fishing Activities * Exposure and Effects of Lead from Various Sources in Plants, Animals, and Humans * Exposure to and Effects of Ingested Lead Shot, Bullets, and Fishing Tackle by Fish, Amphibians, Reptiles, Birds, and Mammals Including Humans • Regulations and Bans on Lead Ammunition and Fishing Tackle * Results of Current Lead Bans for Hunting, Shooting Sports, and Fishing Activities • Alternatives to Lead and Their Current Use in Hunting, Shooting Sports, and Fishing Activities • Research and Monitoring Needs on Exposure and Effects of Lead Shot, Bullets, and Fishing Tackle on Organisms and Their Habitat • Summary * Management Implications

4. Lead – The Element • Naturally occurring element in the environment • Three main isotopes: 206Pb 207Pb 208Pb • No known functional or beneficial role in humans or other living organisms

5. Introduction • Numerous uses in ancient Rome and Egypt (water pipes, pottery, wine making) • Toxic effects well known at that time • Hypothesized to have contributed to the fall of the Roman Empire

6. Introduction • Used as fishing net sinkers during the Bronze Age • Pb shot and bullets appeared with the development of gunpowder and firearms in the 14th century

7. Introduction • Pb is one of the easiest metals to mine and smelt • Use increased dramatically during the industrial revolution (gasoline additive) • Emissions have resulted in global distribution • Ice Pb levels in remote polar regions are orders of magnitude greater than prehistoric times

8. Introduction • Worldwide 3.6 million metric tons refined annually • Major uses include: • Storage batteries • Cable sheathing • Pigments • Chemicals • Alloys • Ammunition

9. Introduction • Toxic effects on humans known for centuries • Neurological, behavioral, and developmental effects well documented in children • Toxic in minute amounts • According to CDC, there may be no threshold (i.e. safe level) for effects on children

10. Bans on Lead – U.S. • 1977 Ban on lead based paints • 1980s Phase out of leaded gasoline • 1991 Ban on lead for waterfowl hunting • 1995 Ban on lead soldering for food cans

11. Effects on Wildlife • Compared to knowledge in humans, recognition of hazard to wildlife is relatively recent • Reported in waterfowl from TX an NC in the late 1800’s • More fully appreciated after classic monograph by Bellrose (1959) “Lead Poisoning as a Mortality Factor in Waterfowl Populations”

12. Comparison of Healthy vs. Lead Poisoned Ducks Photo courtesy of Bryan Richards, National Wildlife Health Lab. Madison, WI (1/22/09).

13. Regulation for Wildlife Protection1970’s -1980’s • United States Endangered bald eagles secondarily poisoned by eating Pb- intoxicated or crippled waterfowl Eventually lead to phase-out by 1991 of Pb shot for hunting waterfowl and coots • Britain Mute swan population decline attributed to poisoning from Pb fishing weights Eventually led to ban of most Pb fishing sinkers by 1986

14. Sources and Estimated Quantities of Lead from Hunting, Shooting Sports, and Fishing Activities

15. Sources and Quantities - Hunting • In waterfowl hunting areas, estimates range from 125,970 to 5,000,000 shot/hectare • Prior to 1991 ban, estimated 2,721 metric tons deposited in U.S. wetlands annually • Annual deposition in upland fields as much as 1,000,000 shot/hectare

16. Sources and Quantities - Hunting Unquantified amounts from varmit hunting, predator control, and big game gut piles

17. Bullet Fragmentation

18. Sources and Quantities - Shooting Sports • U.S. EPA estimates 72,600 metric tons of Pb shot and bullets deposited annually at outdoor shooting ranges • Significant amounts of fine Pb particulate occur in soil close to shooting stations

19. Sources and Quantities - Fishing • Few studies • Estimated 1 metric ton/year lost in MN lakes (lures, large sinkers, spit shot sinkers, jigs, hooks) • Estimated 0.01-0.47 sinkers/m2 along U.S. shorelines

20. Sources and Estimated Quantities of Lead from Hunting, Shooting Sports, and Fishing Activities • Global estimate of Pb ammunition production in 2000 was 194,820 metric tons, accounting for 3% of the lead with end consumer uses

21. Fate of Elemental Lead in Terrestrial Environments • Not inert • Breakdown and transformation to other Pb compounds occurs over 40-300 years depending on soil characteristics, leaching, mechanical disturbance, etc. • Numerous reports document dissolved Pb from shooting ranges entering surface or ground water and exceeding water quality criteria

22. Fate of Elemental Lead in Aquatic Environments • Water at some shooting ranges have levels of dissolved Pb that exceed EPA water quality for aquatic live and drinking water; water at other shooting ranges have no evidence of dissolved Pb • Depends on whether exposed in water, buried in sediments, water flow rate, aerobic conditions, pH, etc. • Generally, Pb in spent shot and lost fishing tackle is thought to be less bioavailable to aquatic organisms compared to Pb introduced into the aquatic environment from atmospheric deposition or wastewater

23. Wildlife Health Case Studies

24. Waterfowl

25. Waterfowl • Source: lead shot ingested from sediment • History of controversy implementing regulations • Switch from lead to non-toxic shot has significantly reduced the number of birds dying of lead poisoning

26. Condors

27. Condors • Source: lead bullets and fragments ingested from gut piles and other carcass remains • Temporal and spatial correlations between big game hunting seasons and elevated lead levels in condors

28. Condors • Responsible for up to 50% of wild condor mortality in Arizona (Cade 2007) • Mortality from lead ammunition well exceeds natural reproductive rate

29. Loons

30. Loons • Source: lead sinkers ingested with sediment, live bait, or escaped fish with attached gear • From 1987-2000, 118/522 (22%) of loon carcasses collected from 5 New England states had ingested lead objects; most (94%) were less than 1” long • In Canada, ingestion of small lead sinkers or jigs accounts for about 20–30% of recorded mortality of breeding adult common loons in habitats that experience high recreational angling activity

31. Eagles

32. Eagles • Source: lead shot, bullets, and fragments in gut piles and other carcass remains • From 1975-2007, 608/3624 (17%) of bald eagles submitted to the National Wildlife Health Center died of lead poisoning

33. Data from J. Langenberg, Wisconsin DNR Of 559 Bald Eagle carcasses submitted to the WDNR between 1994 and 2003, 68 (~12%) of those deaths were attributed to lead poisoning with a peak occurrence during hunting seasons.

34. Mourning Doves

35. Mourning Doves • Source: lead pellets in managed fields • A proportion (possibly 5%) of the dove population feeding at dove hunting field sites have ingested spent lead pellets • Virtually all doves that ingest two or more lead pellets succumb to the direct or indirect effects of lead poisoning within 21 days

36. Trumpeter Swans

37. Trumpeter Swans • Source: lead shot ingested from sediment • From 1999-2008 in NW Washington and SW British Columbia, 1376/1727 (80%) dead swans collected died of lead poisoning

38. Since the 1991 Lead Shot Ban for Hunting Waterfowl : • 44% decline in prevalence of elevated blood levels in American black ducks (Samuel & Bowers 2000) • >50% decline in wing bone lead levels in American black ducks, mallards, ring-necked ducks (Stevenson et at. 2005) • 64% reduction in lead mortality in mallards, generating a savings of 1.4 million ducks per year (Anderson et al. 2000)

39. A Perspective: “The previous 3 studies illustrate that adoption of nontoxic shot for waterfowl hunting has been the most effective tool used by the individual hunter in the conservation of waterfowl in North America. Contribution to survivorship exceeds contributions to waterfowl numbers made by continental habitat manipulations and improvements. Hunters’ purchase and use of nontoxic shot is an activity that directly compliments and enhances the benefits of all types of habitat improvement and expansion.” Vernon G. Thomas, 2008

40. Another Perspective: “The immediate wildlife management issue is not population dynamics but conservation leadership in mediating responsible behavior from one segment of society towards the object of concern of another segment of society.” Lloyd Fox, KDWP

41. Management Implications…. “As stewards of terrestrial and aquatic ecosystems, natural resource management agencies, conservation organizations, manufacturers and retailers of ammunition and fishing tackle, and the public at large work actively and often collectively to protect natural resources. Minimizing the introduction or release of any toxic substance that can evoke serious and unintended adverse effects into the environment is a tenet of such stewardship.”