Toxic effects of gunshot fumes from different ammunitions for small arms on lung cells exposed at the air liquid interface

Espen Mariussen,Lise Fjellsbø,Tomas Roll Frømyr,Ida Vaa Johnsen,Tove Engen Karsrud,Øyvind Albert Voie

doi:10.1016/j.tiv.2021.105095

Abstract

Concerns have been raised as to whether gunshot fumes induce prolonged reduced lung capacity or even cancer due to inhalation. Gunshot fumes from three different types of ammunition calibre 5.56 mm × 45 NATO were investigated. SS109 has a soft lead (Pb) core, while NM255 and NM229 have a harder steel core. Emissions from ammunitions were characterized with respect to particle number- and mass-size, and mass distribution, heavy metal content, and different gases. Lung epithelial cells were exposed to the fumes at the air liquid interface to elucidate cytotoxicity and genotoxicity. Irrespectively of ammunition type, the largest mass fraction of generated particulate matter (PM) had a size between 1 and 3 μm. The highest number of particles generated was in the size range of 30 nm. Fumes from NM255 and NM229 induced cytotoxic effects of which the emission from NM229 induced the highest effect. Fumes from NM229 induced a dose-related increase in DNA-damage. Significant effects were only achieved at the highest exposure level, which led to approximately 40% reduced cell viability after 24 h. The effect probably relates to the mass of emitted particles where the size may be of importance, in addition to emission of Cu and Zn. A complex mixture of chemical substances and PM may increase the toxicity of the fumes and should encourage measures to reduce exposure.

Highlights

Gunshot fumes from firing small arms contain a complex mixture of gases and aerosols, consisting of both particulate matter (PM) and liq uids
The main difference between the NM255 and NM229 am munitions is a different geometry of the NM255 bullet, resulting in a Toxicology in Vitro 72 (2021) 105095 smaller contact area between the bullet and the gun barrel compared to NM229
The small arms ammunitions used in this investigation consisted of a cartridge with a propellant and a projectile with a metal core of steel or lead, jacketed with a copper (90%) and zinc (10%) alloy, and a primer, Fig. 6

Summary

Introduction

Gunshot fumes from firing small arms contain a complex mixture of gases and aerosols, consisting of both particulate matter (PM) and liq uids. In 2003, the Norwegian armed forces changed their primary assault rifle to the HK416 (Heckler & Koch, Germany). After the new weapon was put into service, flu like symptoms after training ses sions at firing ranges were reported. It became evident that the symp toms were due to exposure to gunshot fumes. The symptoms were similar to what previously have been observed among welders (Voie et al, 2014). The symptoms were attributed to the newly introduced ammunition with a steel core instead of a lead (Pb) core, and further use of this ammunition type was temporarily prohibited

Methods

Results

Conclusion