title: Grain-size normalization as a tool to assess contamination in marine sediments: is the <63 micron fraction fine enough?
abstract: A common method for compensating for grain-size differences in suites of sediment samples is to normalize potential contaminants by regression with a particular grain-size fraction, the <63 microm fraction being most often selected. However, this fraction is unlikely to represent accurately the clay content, which represents a major factor in the ability of sediments to adsorb contaminants. Moreover, no reliable estimation of clay content can be made from a coarser grain-size fraction. As a result, regression with coarser-grained fractions can produce spurious interpretations of background values and contamination. Normalization with the clay content or by an alternative grain-size proxy is recommended.
authors.affiliation: Institute of Ecology and Earth Sciences, University of Tartu, Lai 40, 51005 Tartu, Estonia. robszav@ut.ee
authors.forename: Robert C
authors.initials: RC
authors.lastname: Szava-Kovats
mesh_terms: D004784:Environmental Monitoring / Q000379:methods* / Q000592:standards; D019015:Geologic Sediments / Q000737:chemistry*; D010316:Particle Size; D011084:Polycyclic Aromatic Hydrocarbons / Q000032:analysis; D014874:Water Pollutants, Chemical / Q000032:analysis
chemical_list: D011084:Polycyclic Aromatic Hydrocarbons; D014874:Water Pollutants, Chemical