# Airborne and Dermal Collection Methods of Gunshot Residue for Toxicity Studies
## 3 Results/Discussion
### Inhalation Considerations (Filter and DST)
\begin{table}
\begin{tabular}{l c c c c c c c c c c c c} \hline \hline  & & & & \multicolumn{6}{c}{**Double-Sided Tape**} \\ \hline  & Ag & Ba & Cd & Ce & Cs & Pb & Rb & Sr & Th & U & Total & GSR \\ \hline DTT & \(-\)0.094 & 0.102 & \(-\)0.11 & 0.671 & \(-\)0.283 & 0.014 & 0.32 & 0.096 & 0.559 & 0.615 & \(-\)0.055 & \(-\)0.096 \\ \hline Ag & & 0.291 & 0.357 & 0.363 & \(-\)0.283 & \(-\)0.274 & 0.291 & \(-\)0.137 & \(-\)0.056 & 0.363 & \(-\)0.191 & \(-\)0.137 \\ \hline Ba & & & 0.638 & 0.273 & \(-\)0.351 & **0.727** & 0.284 & **0.817** & 0.468 & 0.273 & **0.812** & **0.817** \\ \hline Cd & & & & 0.503 & 0.249 & 0.271 & **0.74** & 0.428 & 0.233 & 0.54 & 0.443 & 0.428 \\ \hline Ce & & & & \(-\)0.085 & \(-\)0.172 & **0.767** & \(-\)0.123 & 0.425 & **0.925 \({}^{*}\)** & \(-\)0.073 & \(-\)0.123 \\ \hline Cs & & & & & \(-\)0.249 & 0.439 & \(-\)0.249 & 0.085 & 0.085 & \(-\)0.247 & \(-\)0.249 \\ \hline Pb & & & & & & \(-\)0.198 & **0.976 \({}^{*}\)** & 0.491 & \(-\)0.049 & **0.970 \({}^{*}\)** & **0.976 \({}^{*}\)** \\ \hline Rb & & & & & & & \(-\)0.108 & 0.351 & **0.754** & \(-\)0.076 & \(-\)0.108 \\ \hline Sr & & & & & & & & & 0.417 & \(-\)0.025 & **0.994 \({}^{*}\)** & **1.000 \({}^{*}\)** \\ \hline Th & & & & & & & & & & 0.625 & 0.415 & 0.417 \\ \hline U & & & & & & & & & & & & 0 & \(-\)0.025 \\ \hline Total & & & & & & & & & & & & & & & \\ Elements & & & & & & & & & & & & & & & \\ \hline \hline \end{tabular}
\begin{tabular}{l c c c c c c c c c} \hline \hline  & Ag & Ba & Cd & Ce & Cs & Pb & Rb & Sr & Th & U & Total & GSR \\ \hline DTT & n/a & \(-\)0.361 & \(-\)0.079 & 0.034 & 0.169 & \(-\)0.532 & 0.007 & 0.311 & 0.311 & 0.169 & \(-\)0.501 & \(-\)0.532 \\ \hline Ag & & n/a & n/a & n/a & n/a & n/a & n/a & n/a & n/a & n/a & n/a & n/a \\ \hline Ba & & & 0.061 & **0.628** & **0.593** & **0.912 \({}^{*}\)** & 0.339 & 0.081 & 0.081 & **0.593** & **0.891 \({}^{*}\)** & **0.912 \({}^{*}\)** \\ \hline Cd & & & & 0.486 & 0.191 & 0.201 & \(-\)0.354 & **0.626** & **0.626** & 0.191 & 0.201 & 0.201 \\ \hline Ce & & & & & **0.795 \({}^{*}\)** & **0.598** & 0.270 & **0.565** & **0.565** & **0.795 \({}^{*}\)** & **0.598** & **0.598** \\ \hline Cs & & & & & **0.564** & 0.475 & **0.565** & **0.565** & **1 \({}^{*}\)** & **0.564** & **0.564** \\ \hline Pb & & & & & & 0.349 & 0.077 & 0.077 & **0.564** & **0.983 \({}^{*}\)** & **1 \({}^{*}\)** \\ \hline Rb & & & & & & & \(-\)0.188 & \(-\)0.188 & 0.475 & 0.457 & 0.349 \\ \hline Sr & & & & & & & **1 \({}^{*}\)** & **0.565** & 0.077 & 0.077 \\ \hline Th & & & & & & & & **0.565** & 0.077 & 0.077 \\ \hline U & & & & & & & & & **0.564** & **0.564** \\ \hline Total & & & & & & & & & & **0.983 \({}^{*}\)** \\ Elements & & & & & & & & & & & \\ \hline \hline \end{tabular}
\end{table} 
Table 2: _Cont._from the complex matrix of the borosilicate glass filters, this can be reduced by using different filter membrane materials in future work or collecting broader size ranges, for example particles up to 10 microns. The DST samples collected airborne particles, of all sizes that were released out of the firearm in the vicinity of the shooting event. The non-size-selective nature of the samples allows for a more robust analysis of the particles present, as larger particles are inhalable but generally with fates in the upper respiratory system [36]. This method of detection is used primarily in the forensic sciences field where tape is patted on the hands of a suspect to determine the presence of GSR [4; 13]. In contrast to previous work, DST served as a non-size-selective, passive method of atmospheric collection of particles in our study. To optimize the passive collection in this study, the tape was placed in closer proximity to the weapon than in previous studies of GSR deposition [9; 11].