; (ii) measure impact over 24-hour, 72-hour to 96-hour, monthly, annual, and lifetime periods; (iii) ensure that the thresholds are low enough that they are not associated with cognitive deficits after firing; (iv) include thresholds that account for the firing of multiple types of heavy weaponry and use of grenades in one period of time; (v) include minimum safe distances and levels of exposure for observers and instructors