Analysis of gunshot residues from nontoxic ammunition: a contribution to health and environmental analysis

This study's aim was to determine the presence, as well as to evaluate the health and environmental impacts, of chemical elements from firearm shots during shooter practice at outdoor shooting ranges, both in the environment and on the shooters' hands. Two high-precision devices were used for measuring suspended particles that are released during discharge of Taurus PT 100 .40 caliber pistols. The analysis of collected data allowed the identification of specific distribution patterns of samples that were adsorbed. Moreover, samples were collected from the opisthenar area of the hand to investigate both the occurrence and deposition of particles and chemical elements through scanning electron microscopy coupled with energy dispersive spectroscopy (SEM-EDS). The results indicate that copper, lead, and zinc concentration profiles will be able to delimit and reveal more precise details regarding shots made with nontoxic ammunition (NTA). In particular, the residual graphic analysis indicated that the majority of metal deposited in the shooter's hand is zinc. Further, the metals barium and lead also were detected. Due to the exposure to these elements, it could be concluded that engineering controls and administrative management should be sought in order to avoid human overexposure and environmental release of these airborne toxic metals.

Cuticular signature in the development of Polistes versicolor

Wasps belong to societies that are highly complex and diverse, especially considering social organization and parental care. They use chemicals in their daily communication, and act incisively in recognition of mates and non-nest mates, and can even identify individuals of different castes. In this study, cuticle composition was examined during the development of Polistes versicolor from the egg stage to adulthood, with the aim to assess changes in the chemical signature of the species, using gas chromatography. Linear alkanes and branched alkanes were identified that were important to distinguish the various developmental stages of P. versicolor. The variation in the linear alkanes and branched alkanes was quantitative, since most of them are present in all stages, with the exception of some linear alkanes that uniquely characterized the egg stage. At the egg stage, differences were predominant for linear alkanes C8, C24, C27, and C29. For the larval instars, there was a predominance of linear alkanes C8, C22 and C24 to C30. In the pre-pupae, pupae and adult stages, C8, C22, C24, and C26 to C30 showed a higher abundance during later developmental stages. The addition to branched alkanes increased their abundance from the egg (13.52%) to adult (22.96%) stages.