Assessment of the environmental toxicity and carcinogenicity of tungsten-based shot.

Assessment of the environmental toxicity and carcinogenicity of tungsten-based shot.

Ecotoxicology and environmental safety (2009-02-24)

Vernon G Thomas, Michael J Roberts, Paul T C Harrison

PMID19232723

ABSTRACT

The toxicity of elemental tungsten released from discharged shot was assessed against previous studies that established a 1% toxic threshold for soil organisms. Extremely heavy theoretical shot loadings of 69,000shot/ha were used to generate estimated environmental concentrations (EEC) for two brands of tungsten-based shot containing 51% and 95% tungsten. The corresponding tungsten EEC values were 6.5-13.5mg W/kg soil, far below the 1% toxic threshold. The same shot loading in water produced tungsten EEC values of 2.1-4.4mg W/L, levels that are not toxic under experimental conditions. Pure tungsten has not been shown to exhibit carcinogenic properties when ingested or embedded in animal tissues, but nickel, with which it is often alloyed, has known carcinogenicity. Given the large number of waterfowl that carry shot embedded in their body, it is advisable to screen lead shot substitutes for their carcinogenic potential through intra-muscular implantation.

MATERIALS

Product Number

Brand

Product Description

267511

Sigma-Aldrich

Tungsten, powder, 12 μm, 99.9% trace metals basis

267546

Sigma-Aldrich

Tungsten, foil, thickness 0.25 mm, ≥99.9% trace metals basis

GF69782349

Tungsten, insulated wire, 5m, conductor diameter 0.075mm, insulation thickness 0.02mm, PTFE (polytetrafluoroethylene) insulation, 99.9%

GF91891266

Tungsten, insulated wire, 10m, conductor diameter 0.05mm, insulation thickness 0.008mm, polyimide insulation, 99.9%

GF18063783

Tungsten, microfoil, disks, 10mm, thinness 0.25μm, specific density 474μg/cm², permanent mylar 3.5μm support, 99.95%

GF14483088

Tungsten, insulated wire, 0.2m, conductor diameter 0.015mm, insulation thickness 0.002mm, polyimide insulation, 99.9%

GF31324384

Tungsten, foil, 5m coil, thickness 0.025mm, coil width 1mm, as rolled, 99.95%

GF21637896

Tungsten, insulated wire, 20m, conductor diameter 0.05mm, insulation thickness 0.008mm, polyimide insulation, 99.9%

GF35250005

Tungsten, foil, not light tested, 50x50mm, thickness 0.004mm, 99.95%

GF28186072

Tungsten, foil, light tested, 150x150mm, thickness 0.05mm, as rolled, 99.95%

GF21631250

Tungsten, lump, 200g, max. size 5mm

GF38958250

Tungsten, insulated wire, 2m, conductor diameter 0.075mm, insulation thickness 0.02mm, PTFE (polytetrafluoroethylene) insulation, 99.9%

GF84684808

Tungsten, rod, 200mm, diameter 6.35mm, centerless ground, 99.95%

GF41314092

Tungsten, foil, light tested, 50x50mm, thickness 0.075mm, as rolled, 99.95%

GF06146805

Tungsten, foil, not light tested, 25x25mm, thickness 0.004mm, 99.95%

GF79060103

Tungsten, insulated wire, 2m, conductor diameter 0.025mm, insulation thickness 0.005mm, polyimide insulation, 99.9%

GF52817878

Tungsten, foil, 30mm disks, thickness 1.0mm, as rolled, 99.95%

GF32754595

Tungsten, foil, light tested, 150x150mm, thickness 0.075mm, as rolled, 99.95%

GF79938039

Tungsten, lump, 50g, max. size 5mm

GF52385799

Tungsten, insulated wire, 1m, conductor diameter 0.015mm, insulation thickness 0.002mm, polyimide insulation, 99.9%

GF90717666

Tungsten, microfoil, disks, 10mm, thinness 0.05μm, specific density 96μg/cm², permanent mylar 3.5μm support, 99.95%

GF75672254

Tungsten, insulated wire, 2m, conductor diameter 0.0125mm, insulation thickness 0.0035mm, polyimide insulation, 99.9%

GF11784449

Tungsten, foil, light tested, 150x150mm, thickness 0.025mm, as rolled, 99.95%

GF73441199

Tungsten, microfoil, disks, 10mm, thinness 0.1μm, specific density 182μg/cm², permanent mylar 3.5μm support, 99.95%

GF95973216

Tungsten, wire reel, 0.5m, diameter 1.0mm, clean, 99.95%

GF24694049

Tungsten, insulated wire, 2m, conductor diameter 0.015mm, insulation thickness 0.002mm, polyimide insulation, 99.9%

GF10563342

Tungsten, foil, not light tested, 50x50mm, thickness 0.007mm, 99.95%

GF86719461

Tungsten, foil, not light tested, 25x25mm, thickness 0.006mm, 99.95%

GF78600764

Tungsten, rod, 100mm, diameter 5.0mm, centerless ground, 99.95%

GF27394702

Tungsten, mesh, 100x100mm, nominal aperture 0.2mm, wire diameter 0.05mm, 100 wires/inch, open area 64%, plain weave mesh, 99.95%