Diane Beauchemin

Test firing a firearm is frequently used for forensic firearms and bullet identification. Airborne lead-containing particles are emitted when a firearm is tested, leading to lead building up on surfaces, exposing employees to potential lead-related health risks. Prior to cleaning, lead surface concentrations in the firing range at the National Forensic Laboratory Services in Ottawa were found to be higher than the Environmental Abatement Council of Ontario (EACO) post-abatement limit, with the highest level 56 times the limit. Inductively coupled plasma–mass spectrometry (ICP-MS), along with internal standardization, revealed that wiping surfaces with either a commercial decontamination product containing ethylene glycol butyl ether (EGBE) or alcohol cleaning pads satisfied the EACO standard by removing over 90% of lead from test surfaces whereas an external cleaning company only removed 36% of lead from the same surfaces. Fortunately, lead cross-contamination was minimal outside the firearms section and well below the residential EACO limit.

This study shows, for the first time, that limits of detection (LOD) can be improved for P, S and Ca nanoparticles by the addition of N2 to the plasma flow for single-particle inductively coupled plasma–mass spectrometry (spICP-MS). The work also examined the relative LOD differences using Ar-N2 and Ar-N2-H2 mixed-gas plasmas.