Elemental mercury in the atmosphere of a tropical Amazonian forest (French Guiana)
Résumé
Gaseous atmospheric mercury was investigated at two sites of a tropical Amazonian forest (French Guiana) in the Petit Inini River basin and the Petit Saut Lake in June, 1998. Gaseous atmospheric mercury was identified as elemental mercury (Hg0). Diurnal variation of atmospheric Hg0 in both studied aquatic environments were significantly correlated with air temperature and anticorrelated with relative humidity. Average Hg0 concentrations were higher above the Petit Inini River (75 pmol m-3/15.0 ng m-3) than the Petit Saut Lake (14 pmol m-3/2.8 ng m-3). Background Hg0 concentrations in the Petit Inini River basin were higher (27 pmol m-3/5.4 ng m-3) than those observed in remote environments. These data suggest that gold mining activity (i.e., Petit Inini River basin) may influence mercury mobilization in tropical forest ecosystems and that atmospheric transfer is a major pathway for mercury cycling in these environments. Gaseous atmospheric mercury was investigated at two sites of a tropical Amazonian forest (French Guiana) in the Petit Inini River basin and the Petit Saut Lake in June, 1998. Gaseous atmospheric mercury was identified as elemental mercury (Hg0). Diurnal variation of atmospheric Hg0 in both studied aquatic environments were significantly correlated with air temperature and anticorrelated with relative humidity. Average Hg0 concentrations were higher above the Petit Inini River (75 pmol m-3/15.0 ng m-3) than the Petit Saut Lake (14 pmol m-3/2.8 ng m-3). Background Hg0 concentrations in the Petit Inini River basin were higher (27 pmol m-3/5.4 ng m-3) than those observed in remote environments. These data suggest that gold mining activity (i.e., Petit Inini River basin) may influence mercury mobilization in tropical forest ecosystems and that atmospheric transfer is a major pathway for mercury cycling in these environments.