Litterfall mercury dry deposition in the eastern USA
Environmental Pollution. 161: 284-290.
Mercury (Hg) in autumn litterfall frompredominately deciduous forestswas measured in 3 years of samples from 23 Mercury Deposition Network sites in 15 states across the eastern USA. Annual litterfall Hg dry depositionwas significantly higher (median 12.3 micrograms per square meter (µg/m2), range 3.5-23.4 µg/m2) than annual Hg wet deposition (median 9.6 µg/m2, range 4.4-19.7 µg/m2). The mean ratio of dry to wet Hg deposition was 1.3-1. The sum of dry and wet Hg deposition averaged 21 µg/m2 per year and 55% was litterfall dry deposition. Methylmercury was a median 0.8% of Hg in litterfall and ranged from 0.6 to 1.5%. Annual litterfall Hg and wet Hg deposition rates differed significantly and were weakly correlated. Litterfall Hg dry deposition differed among forest-cover types. This study demonstrated howannual litterfall Hg dry deposition rates approximate the lower bound of annual Hg dry fluxes.
KeywordsMercury; Litterfall; Dry deposition; Wet deposition; Methylmercury
Risch, Martin R.; DeWild, John F.; Krabbenhoft, David P.; Kolka, Randall K.; Zhang, Leiming. 2012. Litterfall mercury dry deposition in the eastern USA. Environmental Pollution. 161: 284-290. https://doi.org/10.1016/j.envpol.2011.06.005.