Fig. 3

Copper exposure measured in the breathing zone of instructors. A Average 8 h TWA Cu measurements at both WPAFB and JBC based on class type. Not including canceled M4 class. Error bars represent SEM. *p < 0.01. #p < 0.01 versus WPAFB. n shown above x-axis. B Total copper measurements collected at WPAFB. C Cu measured in the respirable range at WPAFB. D Total Cu measurements collected at JBC. E Cu measured in the respirable range at JBC. Error bars represent SEM. “Small Class” represents a class size of less than 5 students and contains data from both M4 and M9 refire events. 8 rds = 8 rounds of ammunition fired. “Clean” indicates a day with no class at JBC in which range instructors were cleaning the range