Formation and Evasion of Dissolved Gaseous Mercury in Large Enclosures Amended with super(200)HgCl sub(2)

• Published in: Atmospheric environment (1994) 2004-08, Vol.38 (26), p.4279-4279
• Main Authors: Amyot, M, Southworth, G, Lindberg, SE, Hintelmann, H, Lalonde, J D, Ogrinc, N, Poulain, A J
• Format: Article
• Language: English
• ISSN: 1352-2310
• DOI: 10.1016/j.atmosenv.2004.05.002

Four cylindrical enclosures open to sediments and the atmosphere were installed in June 2000 in a small bay of Lake 239 in the Experimental Lakes Area, Ontario, Canada, and dissolved gaseous mercury levels were followed in the enclosures that received either a single large addition of radiolabeled divalent Hg or a series of smaller additions. Short-term incubation experiments were also conducted to estimate photoreduction rates in and outside the enclosures at different times and to assess the chemical and biological contributions to Hg reduction. Extremely high dissolved gaseous Hg photoproduction was observed, which was explained, at least in part, by the substantial decrease of total radiolabeled Hg in the water column of the enclosures. Evasion rates decreased strongly within the first 8 d following a fresh Hg spike. In the short-term incubations, dissolved gaseous Hg production corrected for integrated solar radiation was correlated to the amount of Hg(II) added prior to incubation.