%0 Journal Article
%T Using Lead Concentrations and Stable Lead Isotope Ratios to Identify Contamination Events in Alluvial Soils
%A Diane Saint-Laurent
%A Julien St-Laurent
%A Marlies H£¿hni
%A Bassam Ghaleb
%A Camille Chapados
%J Applied and Environmental Soil Science
%D 2010
%I Hindawi Publishing Corporation
%R 10.1155/2010/235210
%X Soils contaminated with hydrocarbons ( C 1 0 - C 5 0 ) , polycyclic aromatic hydrocarbons (PAHs), and other contaminants (e.g., As, Cd, Cu, Pb) were recently discovered on the banks of the Saint-Fran£¿ois and Massawippi rivers. Alluvial soils are contaminated over a distance of 100 kilometers, and the level of the contaminated-hydrocarbon layer in the soil profiles is among the highest at the Windsor and Richmond sites. Concentrations of lead and stable lead isotope ratios ( 2 0 4 P b / 2 0 6 P b , 2 0 7 P b / 2 0 6 P b , 2 0 8 P b / 2 0 6 P b ) are also used to identify contamination events. The maximum and minimum values detected in soil profiles for arsenic, cadmium, and lead vary from 3.01 to 37.88£¿mg k g £¿ 1 (As), 0.11 to 0.81£¿mg k g £¿ 1 (Cd) 12.32 to 149.13£¿mg k g £¿ 1 (Pb), respectively, while the 207Pb/206Pb isotopic ratio values are between 0.8545 and 0.8724 for all the profiles. The highest values of trace elements (As, Pb and Zn) were detected in the hydrocarbon layer ( C 1 0 - C 5 0 ) , most often located at the bottom of the profiles (160, 200, and 220£¿cm in depth). The various peaks recorded in the soils and the position of the profiles suggest that various contaminants were transported by the river on several occasions and infiltrated the soil matrix or deposited on floodplains during successive floods. Atmospheric particles which entered the river or deposited on riverbanks must also be considered as another source of pollution recorded in soils. 1. Introduction In the recent years, a growing number of environmental science studies on soil and sediment contamination were characterized by the use of lead stable isotopes to determine the source and origin of this element (geogenic or anthropic) and to evaluate its persistence in the environment [1¨C3]. Mining and industrial activity have introduced various forms of lead pollutants into the environment and the intensive use of fossil fuels has also resulted in lead and several other heavy metals affecting the environment to varying degrees [4, 5]. In the past two decades, research has examined lead isotope signatures to trace emission sources and assessed spatial and temporal changes of recent lead pollution originating from lead smelters and manufacturing plants and from the use of alkyllead in petroleum products, particularly before 1990 [6, 7]. The atmosphere is recognized as major means of transport [8], but fluvial transport also constitutes a vector of pollution [9¨C11]. Studies also examined lead contamination in soils, sediments and groundwater aquifers along with other metals that are
%U http://www.hindawi.com/journals/aess/2010/235210/