title: Mercury in Pleurozium schreberi and Polytrichum commune from areas with various levels of Hg pollution--an accumulation and desorption experiment with microscopic observations.
abstract: Because of its high mobility in ecosystems, mercury is one of the main toxic threats to the environment, and its concentration must be carefully controlled. To fulfill this need, we selected terrestrial mosses with different characteristic life forms: orthotropic and endohydric Polytrichum commune and plagiotropic and ectohydric Pleurozium schreberi. The concentrations of mercury were determined in both species growing together at sites situated approximately 0.75, 1.5, 3 and 6km to the north, south, east and west, respectively of five known mercury polluters. The mercury concentrations reflected the emissions produced by the surrounding industry, reaching values of 0.44mgkg(-1) in P. schreberi and 0.79mgkg(-1) in P. commune in the vicinity of the chlor-alkali industry. To determine how long a load of Hg would remain in the mosses after mercury emitters restricted releases of Hg to the atmosphere, accumulation and desorption experiments were performed. We compared the two moss species collected from clean and moderately and heavily mercury-polluted sites. After eight days of exposure to mercury, P. schreberi accumulated up to 25mgkg(-1) of Hg, and P. commune accumulated up to 31mgkg(-1). Both in the field and in the experiment, P. commune accumulated significantly higher concentrations of Hg than did P. schreberi, most likely because of its surface morphology, which is likely to enhance the capture of metal from the atmosphere. After sixteen days of exposure, mercury changed the structure of the plasma membrane and affected organelles such as the nuclei and chloroplasts, leading to cell disintegration and death. The negative effects of mercury on the functioning of living cells appeared first in the older leaves of P. schreberi. After 64 days growing in the absence of Hg, P. schreberi clearly retained only 10-14% of the initially accumulated Hg, while P. commune retained 10-21%.
authors.affiliation: Department of Ecology, Biogeochemistry and Environmental Protection, University of Wrocław, ul. Kanonia 6/8, 50-328 Wrocław, Poland.
authors.forename: Krzysztof
authors.initials: K
authors.lastname: Zawadzki
authors.affiliation: Department of Plant Developmental Biology, Institute of Experimental Biology, University of Wrocław, Poland. Electronic address: kasias@biol.uni.wroc.pl.
authors.forename: Katarzyna
authors.initials: K
authors.lastname: Sokołowska
authors.affiliation: Department of Ecology, Biogeochemistry and Environmental Protection, University of Wrocław, ul. Kanonia 6/8, 50-328 Wrocław, Poland. Electronic address: aleksandra.samecka@uni.wroc.pl.
authors.forename: Aleksandra
authors.initials: A
authors.lastname: Samecka-Cymerman
authors.affiliation: Department of Ecology, Biogeochemistry and Environmental Protection, University of Wrocław, ul. Kanonia 6/8, 50-328 Wrocław, Poland. Electronic address: krzysztof.kolon@uni.wroc.pl.
authors.forename: Krzysztof
authors.initials: K
authors.lastname: Kolon
authors.affiliation: University School of Physical Education in Cracow, Faculty of Physical Education and Sport, Department of Geography in Tourism, Poland.
authors.forename: Anna
authors.initials: A
authors.lastname: Dubińska
authors.affiliation: Radboud University Nijmegen, Institute for Water and Wetland Research, Department of Environmental Science, Huygens building, Heyendaalseweg 135, 6525 AJ Nijmegen, The Netherlands. Electronic address: L.Kempers@science.ru.nl.
authors.forename: Alexander J
authors.initials: AJ
authors.lastname: Kempers
mesh_terms: D000393:Air Pollutants / Q000032:analysis / Q000633:toxicity; D001272:Atmosphere; D019068:Bryopsida / Q000737:chemistry* / Q000187:drug effects; D017753:Ecosystem; D004784:Environmental Monitoring / Q000379:methods*; D008628:Mercury / Q000032:analysis* / Q000633:toxicity; D011044:Poland
chemical_list: D000393:Air Pollutants; D008628:Mercury
keywords: Cell death; Ectohydric; Endohydric; Metal; Terrestrial mosses