title: (222)Rn activity in groundwater of the St. Lawrence Lowlands, Quebec, eastern Canada: relation with local geology and health hazard.
abstract: One hundred ninety-eight groundwater wells were sampled to measure the (222)Rn activity in the region between Montreal and Quebec City, eastern Canada. The aim of this study was to relate the spatial distribution of (222)Rn activity to the geology and the hydrogeology of the study area and to estimate the potential health risks associated with (222)Rn in the most populated area of the Province of Quebec. Most of the groundwater samples show low (222)Rn activities with a median value of 8.6 Bq/L. Ninety percent of samples show (222)Rn activity lower than 100 Bq/L, the exposure limit in groundwater recommended by the World Health Organization. A few higher (222)Rn activities (up to 310 Bq/L) have been measured in wells from the Appalachian Mountains and from the magmatic intrusion of Mont-Saint-Hilaire, known for its high level of indoor radon. The spatial distribution of (222)Rn activity seems to be related mainly to lithology differences between U-richer metasediments of the Appalachian Mountains and magmatic intrusions and the carbonaceous silty shales of the St. Lawrence Platform. Radon is slightly enriched in sodium-chlorine waters that evolved at contact with clay-rich formations. (226)Ra, the parent element of (222)Rn could be easily adsorbed on clays, creating a favorable environment for the production and release of (222)Rn into groundwater. The contribution of groundwater radon to indoor radon or by ingestion is minimal except for specific areas near Mont-Saint-Hilaire or in the Appalachian Mountains where this contribution could reach 45% of the total radioactive annual dose.
authors: GEOTOP and Département des sciences de la Terre et de l'atmosphère, Université du Québec à Montréal, CP 8888 Succ. Centre-ville, H3C 3P8, Montréal, QC, Canada. Electronic address: pinti.daniele@uqam.ca.
authors: Daniele L
authors: DL
authors: Pinti
authors: GEOTOP and Département des sciences de la Terre et de l'atmosphère, Université du Québec à Montréal, CP 8888 Succ. Centre-ville, H3C 3P8, Montréal, QC, Canada.
authors: Sophie
authors: S
authors: Retailleau
authors: GEOTOP and Département des sciences de la Terre et de l'atmosphère, Université du Québec à Montréal, CP 8888 Succ. Centre-ville, H3C 3P8, Montréal, QC, Canada.
authors: Diogo
authors: D
authors: Barnetche
authors: GEOTOP and Département des sciences de la Terre et de l'atmosphère, Université du Québec à Montréal, CP 8888 Succ. Centre-ville, H3C 3P8, Montréal, QC, Canada.
authors: Floriane
authors: F
authors: Moreira
authors: GEOTOP and Department of Chemistry and Biogeochemistry, Concordia University, 7141 Sherbrooke Street West, H4B 1R6 Montréal, QC, Canada.
authors: Anja M
authors: AM
authors: Moritz
authors: GEOTOP and Département des sciences de la Terre et de l'atmosphère, Université du Québec à Montréal, CP 8888 Succ. Centre-ville, H3C 3P8, Montréal, QC, Canada.
authors: Marie
authors: M
authors: Larocque
authors: GEOTOP and Department of Chemistry and Biogeochemistry, Concordia University, 7141 Sherbrooke Street West, H4B 1R6 Montréal, QC, Canada.
authors: Yves
authors: Y
authors: Gélinas
authors: Institut national de la recherche scientifique, Centre Eau Terre Environnement (INRS-ETE), 490 rue de la Couronne, G1K 9A9 QC, Canada.
authors: René
authors: R
authors: Lefebvre
authors: GEOTOP and Département des sciences de la Terre et de l'atmosphère, Université du Québec à Montréal, CP 8888 Succ. Centre-ville, H3C 3P8, Montréal, QC, Canada.
authors: Jean-François
authors: JF
authors: Hélie
authors: GEOTOP and Département des sciences de la Terre et de l'atmosphère, Université du Québec à Montréal, CP 8888 Succ. Centre-ville, H3C 3P8, Montréal, QC, Canada.
authors: Arisai
authors: A
authors: Valadez
mesh_terms: D004781:Environmental Exposure; D062305:Geographic Mapping; D060587:Groundwater / Q000032:analysis*; D006801:Humans; D011792:Quebec; D011834:Radiation Monitoring; D011886:Radon / Q000032:analysis*; D012588:Scintillation Counting; D062206:Spatial Analysis; D014875:Water Pollutants, Radioactive / Q000032:analysis*; D060986:Water Wells / Q000032:analysis
chemical_list: D014875:Water Pollutants, Radioactive; D011886:Radon
keywords: Groundwater; Health hazards; Mont-Saint-Hilaire; Quebec; Radium; Radon