Presentation on theme: "Environmental Risks Arising from Changes in Ammunition Materials XXIV European Shooting Confederation General Assembly, Moscow 17 May 2013."— Presentation transcript:
Environmental Risks Arising from Changes in Ammunition Materials XXIV European Shooting Confederation General Assembly, Moscow 17 May 2013
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.
Lead and its compounds are Hazardous and Toxic to humans and the Environment. Risk is greater if Lead becomes soluble or mobile. Risk is greater from Leads sparingly soluble corrosion products : PbO, PbO 2, Pb(OH) 2, PbCO 3, Pb 3 (CO 3 ) 2 (OH) 2 … Leads soluble salts: PbSO 4, PbCl 2 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.
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. Whats in my shot? Whats in already in our range soil? What effect will steel shot have on our range?
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
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.
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. 0.5cm
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.
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.
Dont 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/CaCO 3 /MgCO 3, 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!
Dr Peter J. Hurley Cylenchar Limited Tel: +44-(0)1484-517417 Fax: +44-(0)1484-516098 e-mail: firstname.lastname@example.org email@example.com www.cylenchar.com