Assessment of shooter's task-based exposure to airborne lead and acidic gas at indoor and outdoor ranges

Airborne lead and acidic gasses are generated through combustion and mechanical abrasion of ammunition constituents during shooting events. Shooters and other personnel at shooting ranges are exposed to these airborne toxicants and the potential health risks of irritation, nervous system damage, and cancer. Past studies primarily focused on full-length work-shift exposure to lead with little research examining short-term task-based exposure. The objective of this study was to measure the shooters' task-based personal exposure to total fume, lead, and acidic gasses during two-hour shooting sessions at indoor and outdoor shooting ranges. Both pistols and rifles were used, and about 180 rounds of ammunition were fired per shooting session. Total fume was collected by inhalable and respirable fractions and determined gravimetrically. Airborne lead and acidic gasses were analyzed using an inductively coupled plasma mass spectrometer and an ion chromatograph, respectively. The results indicated that significant amount of aerosol mass was in the respirable fraction (0.4-2.8 mg/m3) and inhalable fraction (0.6-3.5 mg/m3). The respirable airborne lead concentration during two-hour shooting sessions was between 0.2 and 1.7 mg/m3, although not directly comparable, were exceeding the Occupational Safety and Health Administration 8-h time-weighted-average permissible exposure limit (PEL) of 0.05 mg/m3. Hydrochloric acid was detected at levels lower than the PEL, during some outdoor shooting sessions possibly due to the presence of corrosive ammunitions. Sulfuric acid was detected and above the PEL during outdoor shooting sessions, but potential measurement artifacts exist in the standard method. Indoor ventilation effectively removed gaseous pollutants, but unable to migrate the particulate fume and lead exposure to acceptable levels. Outdoor ventilation relied more upon natural weather and had a larger deviation. Rifle shooting produced more exposure than did pistol shooting, but the finding was reversed after the exposure was adjusted to ammunition propellant loadings. The present study confirmed the shooter's exposure to airborne lead and some acidic gasses at levels higher than comparable PEL values. More engineering controls and administrative management should be sought to prevent overexposure to these airborne toxicants.