National environmental regulations lack short-term standards for variability in fine particulate matter (PM 2.5 ); they depend soley on concentration-based standards. Twenty-five years of research has linked short-term PM 2.5 ; that is, increases of at least 10 ug/m 3 that can occur in-between regulatory readings, to increased mortality (Di et al, 2017; Staniswalis et al, 2005; Conroy et al, 2001; Schwartz, 1994). Even as new technologies have emerged that could readily monitor short-term PM 2.5 , such as real-time monitoring and mobile monitoring, their primary application has been for research, not for air quality management. The Gulf oil spill offers a strategic setting in which regulatory monitoring, computer modeling, and stationary monitoring could be directly compared to mobile monitoring. Mobile monitoring was found to best capture the variability of PM 2.5 during the disaster. The research also found that each short-term increase (10-μg/m 3 ) in fine particulate matter was associated with a statistically significant increase of 0.105 deaths (p<0.001) in people aged 65 and over, a result that is in line with other studies. These findings contribute to understanding the effects of PM 2.5 on mortality during a disaster, and they provide justification for environmental managers to monitor the variability of PM 2.5 , not only the concentration.