Persistent Mercury Contamination in Shooting Range Soils: The Legacy from Former Primers.

Mercury (Hg) compounds were used in the past in primers for rifle and handgun ammunition. Despite its toxicity, little is known about the contamination of shooting-range soils with this metal. We present new data about the Hg contamination of surface soils from numerous shooting ranges of Switzerland. Our study demonstrates that Hg is measurable at high levels in surface soils from the shooting ranges. In three of the investigated ranges, concentrations above the maximum Swiss guidance value of Hg in soil of 500 µg kg-1 were measured. Since the use of mercury-containing ammunition was stopped in the 1960s, our results demonstrate the high persistence of Hg in soils and their slow recovery by natural mechanisms.