A number of Norwegian soldiers have reported health problems after live-fire training using the HK416 rifle. The objective of this study was to characterize gaseous and particulate emissions from three different types of ammunition, and record the health effects after exposure to emissions from live-firing. Fifty-five healthy, non-smoking men (mean age 40 years) were recruited and divided randomly into three groups, one for each type of ammunition. All subjects fired the HK416 rifle in a semi-airtight tent for 60 min using leaded ammunition, unleaded ammunition and modified unleaded ammunition. Gaseous and particulate emissions were monitored within the tent. The symptoms experienced by the subjects were recorded immediately after and the day after firing using a standardized questionnaire. The concentrations of particulate matter and copper exceeded their respective occupational exposure limits (eight hours per day, five days a week) by a factor of 3 and 27, respectively. Of the 55 subjects, 54 reported general and respiratory symptoms. The total number of symptoms reported was significantly higher among shooters using unleaded ammunition as compared with the use of leaded and modified unleaded ammunition. Copper was the substance that had the highest concentration relative to its toxicity. Although the general symptoms were found to be consistent with the development of metal fume fever, the respiratory symptoms indicated an irritant effect of the airways different from that seen in metal fume fever. More symptoms were reported when unleaded ammunition was used compared with leaded and modified unleaded ammunition.
Background: Norwegian Armed Forces received reports of acute respiratory symptoms after exposure to fumes from firing small arms HK416 using lead free ammunition. The aim of this study was to examine lung function before and after exposure to fumes from HK416 in an experimental setting using three different types of ammunition. Methods: Fifty-five healthy, non-smoking males (age 19-62 years) were randomized to three groups using one of three types of ammunition (SS109 (leaded), NM229 and NM255 (lead free)). Tests of lung function included spirometry and DLCO. The tests were performed less than 14 days before (T 0 ), shortly after (T 1 ) and 24 hours after (T 2 ) shooting. A tent was used for achieving control of the exposure. Exposure was monitored by measuring CO and regulated to keep the level between 200 and 300 ppm Results: FVC, DLCO, NO show the same trend as for FEV1. There are no significant differences (one way Anova) between the different types of ammunition concerning FEV1, FVC, DLCO, NO. Conclusions: All groups show a decline in FEV1 shortly after shooting. 24 hours after exposure FEV1 are still significantly reduced compared to the pretest values (T0). Other lung function tests show the same trend as for FEV1. We believe this is caused by an inflammatory process of the airways.
After introduction of unleaded ammunition, Norwegian Armed Forces received reports of acute respiratory symptoms in soldiers after exposure to fumes from firing the standard weapon, HK416. The aim of the present study was to examine lung function before and after exposure to fumes from HK416 in a double-blinded standardised study design using three different types of ammunition.
Methods
Fifty-four healthy, non-smoking male volunteers (19–62 years) fired the weapons for 60 min with either leaded, unleaded or ‘modified’ unleaded ammunition. Gaseous and particulate emissions were monitored. Spirometry and exhaled nitric oxide (eNO) were performed within 14 days before (T0), shortly after (T1) and 24 hours after (T2) shooting. Methacholine provocation and diffusing capacity of carbon monoxide (DLCO) were carried out at T0 and T2.
Results
The mean forced expiratory volume in 1 s on a group level was significantly reduced both at T1 and T2 compared with T0, with means and 95% CI of 226 mL (158 to 294 mL) and 285 mL (218 to 351 mL), respectively. The same significant pattern was seen for DLCO, forced vital capacity and eNO. The methacholine test indicated a slight increase in bronchial hyper-reactivity. However, there were no significant differences between types of ammunition used.
Conclusion
Exposure to fumes from military weapons might be a respiratory hazard for soldiers who do live-fire training regularly or are in a closed combat environment.
