Vertical characterization of soil contamination using multi-way modeling – A case study Kunwar P. Singh & Amrita Malik & Ankita Basant & Priyanka Ojha Received: 12 June 2007 / Accepted: 6 November 2007 / Published online: 28 November 2007 # Springer Science + Business Media B.V. 2007 Abstract This study describes application of chemo- metric multi-way modeling approach to analyze the dataset pertaining to soils of industrial area with a view to assess the soil/sub-soil contamination, accumulation pathways and mobility of contaminants in the soil profiles. The three-way (sampling depths, chemical variables, sampling sites) dataset on heavy metals in soil samples collected from three different sites in an industrial area, up to a depth of 60 m each was analyzed using three-way Tucker3 model validated for stability and goodness of fit. A two component Tucker3 model, explaining 66.6% of data variance, allowed interpretation of the data information in all the three modes. The interpretation of core elements revealing interactions among the components of different modes (depth, variables, sites) allowed inferring more realistic information about the contam- ination pattern of soils both along the horizontal and vertical coordinates, contamination pathways, and mobility of contaminants through soil profiles, as compared to the traditional data analysis techniques. It concluded that soils at site-1 and site-2 are relatively more contaminated with heavy metals of both the natural as well as anthropogenic origins, as compared to the soil of site-3. Moreover, the accumulation pathways of metals for upper shallow layers and deeper layers of soils in the area were differentiated. The information generated would be helpful in developing strategies for remediation of the contami- nated soils for reducing the subsequent risk of ground- water contamination in the study region. Keywords Three-way component analysis . Tucker3 . Split-half analysis . Residuals analysis . Leverages . Soil contamination . Heavy metals Introduction Industrial activities are mainly responsible for con- tamination of both the land and surface water bodies. Industrial wastewater contains several types of organ- ic as well as inorganic pollutants. Disposal of untreated wastewater on to land surface is a common practice in India and elsewhere due to lack of treatment facilities and may result in accumulation of various contaminants in soils building up their high concentrations over time (Garcia-Diaz and Prats- Montalban, 2005). Persistence of metals in soils is much greater than in any other compartment of the biosphere, and the pollution produced by them is virtually permanent (Mulchi et al., 1991). Heavy metals retained in soil may cause toxic effect and damage to plants, animals and human beings. Their continued input may overwhelm retention capacity of Environ Monit Assess (2008) 146:19–32 DOI 10.1007/s10661-007-0056-x K. P. Singh (*) : A. Malik : A. Basant : P. Ojha Environmental Chemistry Division, Industrial Toxicology Research Centre, Post Box 80, MG Marg, Lucknow 226 001, India e-mail: kpsingh_52@yahoo.com