A comprehensive framework to assess elemental mercury in the Department of Energy: A time series analysis

OBJECTIVE: This study investigated whether seasonal categories affect airborne mercury concentrations in the U.S. Department of Energy operations. METHODS: We conducted an initial assessment of the general variability of airborne elemental mercury time-weighted average (TWA) samples. Then, we performed a two-component time series analysis to determine whether long-term, cyclical temperature change patterns affect mercury concentrations. RESULTS: Both ARIMA time series models demonstrated stationary, non-random means (χ² = 83.8, p < 0.001) and standard deviation (χ² = 55.8, p < 0.001) of mercury concentrations. Our results indicate that the seasonal factors did not influence mercury concentration. CONCLUSIONS: Our results demonstrate that mercury concentrations primarily emanate from operational activities, work practices, and/or transient environmental conditions rather than seasonal fluctuations.