Environmental Risks Arising from Changes in Ammunition Materials

1. Environmental Risks Arising from Changes in Ammunition Materials XXIV European Shooting Confederation General Assembly, Moscow 17 May 2013

2. Risk • Risk is a combination of the probability, or frequency, of occurrence of a defined hazard and the magnitude of the consequences of that hazard. • “Pollutant linkage” - In the context of land contamination, there are three essential elements to any risk: • A contaminant – a substance that is in, on or under the land and has the potential to cause harm or to cause pollution of controlled waters; • A receptor – in general terms, something that could be adversely affected by a contaminant, such as people, an ecological system, property, or a water body; and • A pathway – a route or means by which a receptor can be exposed to, or affected by, a contaminant.

3. The Contaminant – Metallic Lead? • Lead and its compound’s are Hazardous and Toxic to humans and the Environment. • Risk is greater if Lead becomes soluble or mobile. • Risk is greater from Lead’s ‘sparingly soluble’ corrosion products : PbO, PbO2, Pb(OH)2, PbCO3, Pb3(CO3)2(OH)2… • Lead’s soluble salts: PbSO4, PbCl2 are acute poisons • Antique Lead above pH 6.5: the rate of corrosion equates to 2,000-3,200 years for European shot #7 to 9 to corrode. • Practical experience of shot in ranges indicates circa 200 years – even in neutral soils. WHY? “Measurement of corrosion content of archaeological lead artifacts by their Meissner response in the superconducting state; a new dating method”, S Reich, G Leitus and S Shalev, Deutsche Physikalische Gesellschaft. New J. Phys. 5 (July 2003) 99.

4. Metallic Lead Corrosion? • Corrosion of metals is primarily an electrochemical process. Usually requires a sacrificial metal or compound and an electrolyte. • The lower the pH the better the electrolyte. • In the cased of Lead, its corrosion crust does not slow the process. Once initiated, corrosion in linear in nature. • Soil can provide sacrificial metal compounds. • In the absence of sacrificial materials, pure Lead is highly resistive to acid attack. • Soil free study, Pure Lead shot x 5 times slower corrosion than Archaeological Lead. • Unstable lead alloys; 1.25% Sb-Pb increases corrosion x 22 fold compared to pure lead. • Add iron oxides from steel shot corrosion to 1.25%Sb-Pb alloy shot and comparative corrosion increases x 140 fold. • What’s in my shot? What’s in already in our range soil? What effect will steel shot have on our range?

5. Unified Numbering System (UNS) designations for pure lead grades and lead-base alloys. Pure leads L50000 - L50099 Lead - silver alloys L50100 - L50199 Lead - arsenic alloys L50300 - L50399 Lead - barium alloys L50500 - L50599 Lead - calcium alloys L50700 - L50899 Lead - cadmium alloys L50900 - L50999 Lead - copper alloys L51100 - L51199 Lead - indium alloys L51500 - L51599 Lead - lithium alloys L51700 - L51799 Lead - antimony alloys L52500 - L53799 Lead - tin alloys L54000 - L55099 Lead - strontium alloys L55200 - L55299

6. The Contaminant – Metallic Lead?

7. 500µm The Contaminant – Metallic Lead? Exposure to aerated water 20oC pH 6.0-6.5 Day 1 Day 4 Day 3 Day 6 Day 5 Day 2

8. 500µm The Contaminant – Metallic Lead? Exposure to aerated water 20oC pH 6.0-6.5 Day 1 Day 4 Day 3 Day 6 Day 5 Day 2

9. Does Steel Shot Reduce Environmental Risk?

10. European Soils – Typical Profile • Organic rich horizons descending into less organic rich layers of weathered soils, • overlying un-weathered substrata and parent rock. • Grasses, herbs, mosses and lichens; • rooted in underlying thatch and dark organic rich horizon. • Surface typically pH 5.5-7.5. • Presence of soil invertebrates. • Usually find iron banding / iron pan from natural weathering above less oxygen rich regions.

11. 0.5cm Predicted Impact of Steel Shot • Corrosion with liberation of colloidal oxides of: iron, nickel and manganese. • Accelerated corrosion of legacy lead, and liberation of other heavy metals naturally present in the soil; through redox corrosion and iron oxide catalysed oxidation. • Most corrosion/leachate by-products adhere to colloidal iron oxides, surface clays and biomass, (i.e. thatch). Initially reduction in heavy metals leaching. • Adverse impact on surface soil pH, swings from 9.5 to 3.5 in days. Overall effect is a long term increase in site acidity and net increase in metals leaching. • Loss of sensitive mosses and lichens. • Demise of soil invertebrates due to pH changes and oxidative stress, with consequential deterioration in sub-soil drainage • Reduction of intolerant herbs. • Formation of secondary ‘iron-pan’, leading to deterioration in soil texture (with iron concretion) further impede sub-soil drainage, leading to associated increase in surface run-off. • Reduction in grass quality and cover through pH stress, metals toxicity and poorer drainage. • Consequential loss of surface biomass and soils.

12. Site Risk! - Added Contaminants • Contrary to the of labelling ‘Steel Shot’ cartridges, not being Lead does not make them ‘Non-toxic’. • Colloidal Iron oxide – Irritant. Not classified as a human carcinogen - but equivocal tumorigenic, Herbicide. Aquatic pollutant. Toxic to insects / Invertebrates. • Steel shot contains both Manganese and Nickel. • Nickel salts are carcinogenic. • Manganese oxides are Harmful and reduce male fertility. Proven to increase human toxicity of Lead x 3 fold. • Increased level of potentially soluble lead and antimony pollutants by redox corrosion and increased acid corrosion of legacy metals.

13. Site Risk! - Added Pathways • Steel shot provides a transport metal in the form of colloidal iron oxides. • Ferrogenous discharges (so called ‘acid mine discharge’ or ‘yellow-boy’, - i.e. rust laden waters), probably the largest cause of heavy metals migration from contaminated sites. • Increased erosion and mobilisation of heavy metals through facilitated transport on clays and biomass. • Reduced cover, impairment of subsoil drainage soil results in an increase in surface run-off: • Increased runoff – increases risk of soluble pollutant migration.

14. Mitigation of Site Risk • Don’t shoot steel over legacy lead . • Or shoot ‘better’ lead. • Design ranges to better capture spent projectiles. • Routinely remove spent shot from the range. Lead must be mechanically removed, but steel can be removed with a ‘magnetic broom’. • Treat the range with a remediation agent: Apatite/CaCO3/MgCO3, Synthetic Apatite (limited efficacy and can aggravate drainage problems). • Encourage natural drainage and transpiration - plant trees. • Maintain surface cover. • Monitor site soil permeability. • Counter ‘iron pan’ with mechanical intervention to assist surface drainage. • Install range drainage system to capture all runoff, and monitor runoff for potential contaminants. • Incorporate a heavy metals reactive filter/barrier within the range drainage system and projectile traps. ANY FUTURE CHANGES – THINK HOLISTICALLY!

15. Dr Peter J. Hurley Cylenchar Limited Tel: +44-(0)1484-517417 Fax: +44-(0)1484-516098 e-mail: peter.hurley@cylenchar.com www.cylenchar.com