LEAD Action News Volume
13 Number 4, June 2013, ISSN 1324-6011 Incorporating Lead Aware Times ( ISSN 1440-4966) and Lead Advisory Service News (ISSN 1440-0561) The Journal of The LEAD (Lead Education and Abatement Design) Group Inc. Editorial Team: Elizabeth O’Brien, Zac Gethin-Damon, Hitesh Lohani, Shristi Lohani and David Ratcliffe |
|||
About Us
|
Environmental Risks Arising from Changes in Ammunition Materials Copyright © 2013 – Cylenchar Limited Dr Peter J Hurley – Cylenchar Limited UK European Soils – Typical Profile and Predicted Impact of Steel Shot If we consider a hypothetical ‘typical’ European soil, as we might find on a shooting range, we usually see: 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 and underlying thatch and dark organic rich horizon. Surface conditions are typically pH 5.5-7.5. Some upland areas may be 1 pH unit lower and some Mediterranean coastal fringe soils a unit higher. We usually find soil invertebrates. Iron banding from natural weathering is commonly found above less oxygen rich regions. Add steel shot and what is likely to happen? Steel is not simply an alloy of iron and carbon. Corrosion will also liberate colloidal oxides of nickel and manganese in addition to iron. These elements are naturally present in most iron ores and carry through, or are added to finished steel products. Accelerated corrosion of legacy lead, and liberation of other heavy metals naturally present in the soil will occur through redox corrosion and iron oxide catalysed oxidation. This is an important point as even if you put pure iron onto the range, such is the power of iron and its oxides as oxidation catalysts, they will induce breakdown and leaching of previously stable background metal minerals. In other words: Put a significant amount of iron on your range and even if you hadn’t a heavy metals leaching problem, subject to background mineralogy, you are very likely to create one! Most corrosion by-products adhere to colloidal iron oxides, surface clays and biomass. Initially you might see a reduction in heavy metals leaching. Iron corrodes to produce alkaline iron (II) compounds which then go on to acidic iron (III) compounds. Leading to adverse impact on surface soil pH, swings from 9.5 to 3.5 in days. The overall effect is a long term increase in site acidity and net increase in metals leaching. We anticipate and observe pH swings, and the act of corrosion in the soil ‘in and of itself’ takes oxygen out of the soil raising the level of the soil’s zone of anaerobic horizon and reducing the zone in which soil invertebrates can thrive. Iron (II) salts are sold as herbicides, specifically to deter moss. So, how can you expect steel shot through is corrosion products not to have the same effect on range soils. We can anticipate the demise of soil invertebrates due to pH changes and oxidative stress, with consequential further deterioration in sub-soil drainage. Reduction of intolerant herbs and deterioration in grass quality and cover will occur. Formation of secondary a ‘iron-pan’, leading to deterioration in soil texture (with iron concretion) will further impede sub-soil drainage, leading to an increase in surface run-off. The natural consequence of the above is loss of surface biomass and soils. Contents
Environmental Risks Arising from Changes in Ammunition Materials Copyright © 2013 – Cylenchar Limited |
||
About
Us |
bell
system lead poisoning |
Contact Us
| Council
LEAD Project | egroups | Library
- Fact Sheets | Home
Page | Media Releases |
|||
Last
Updated 19 July 2013
Copyright © The LEAD Group Inc. 1991- 2013 PO Box 161 Summer Hill NSW 2130 Australia Phone: +61 2 9716 0014 |