Environmental Contaminants

When interpreting GSR/Pb ratios, great care should be exercised to correctly identify particles containing lead and bromine (Br). These particles are found in the emissions from car exhausts and come from the ethylene dibromide which is used to remove the lead used in the petrol anti-knock compound, lead tetraethyl.

Likewise, barium is also utilized in face powders and a filler in paper. In these situations, it is nearly always associated with sulphur (S) and should be readily identified.

With modern non-corrosive ammunition, it is very rare to find sulphur in a priming compound. In 7.62 x 25 mm and 7.62 x 39 mm ammunition, however, barium and sulphur are often found together in the priming compound and confusion can arise.

Lead is alloyed with antimony in battery plates and type metal. It is also alloyed with tin and/or antimony in solder. This is a common contaminant especially with anyone working in the printing or car repair trade.

Antimony is also used as its oxide as a fire retardant in cotton and polyester blend fibres.

Zirconium and titanium (used in lead- free primer compounds) is used as fluoro-complexes in the treatment of wool.

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