Volume 41, Issue 6 (November 1996)
A Survey of High Explosives Traces in Public Places
This survey was carried out to determine the background levels of explosives traces in public places. Samples were taken at various transport sites. Police sites were also sampled to assess how likely it is that a suspect could be contaminated. The survey showed that traces of the high explosives nitroglycerine (NG), trinitrotoluene (TNT), pentaerythritol tetranitrate (PETN), and cyclotrimethylene trinitramine (RDX) are rare within the general public environment. Only four low level traces of RDX were detected. NG, probably associated with the use of firearms, was detected at a number of police sites, but traces of other explosives were rare. The results of the survey indicate that it is unlikely that someone in public areas could become significantly contaminated with explosives. Traces of NG found on suspects who have had contact with police sites must be interpreted in the light of the survey results. The analytical procedures used would also have detected ethylene glycol dinitrate (EGDN) if present at levels greater than 2 ng, mononitrotoluenes, if present, at levels greater than 50 ng and the most common isomers of dinitrotoluene if these had been present at levels in excess of 10 ng. None of these were detected. The relatively high volatility of EGDN and the mononitrotoluenes would, however, cause traces of these compounds to disperse rapidly.