Reference sediment/soil

Xie, X.J. Yan, M.C., Li, L, Shen, H. 1985. Usable values for Chinese standard reference samples of stream sediments, soils and rocks GSD9-12, GSS1-8 and GSR1-6. Geostandards Newsletter, 5, 211-280. 

Pinfish, Lagodon rhomboides, whole Montana mining waste-contaminated wetland vs. reference site 1990-92 Sediments Soil... 

Reference Rocks Soils Stream - Sediments -Lake Ocean... 

Biomarkers are physiological or biochemical measurements that may be indicative of exposure to contaminants. Although they are not used to estimate risks, they can be used to support other lines of inference (Suter, 1996). Because the effect is seen directly in the population itself, there is no problem with bioavailability, kinetics or other factors that modify the toxicity of the media (water, sediment, soil). A positive response means that the population is exposed to toxicants. The inference is established when the levels of biomarkers from contaminated and reference sites are significantly different. When the levels of biomarkers are characteristic of contaminant exposures, the distribution and frequency of elevated levels should be compared with the distribution and concentrations of contaminants. In addition, the implications of the observed biomarker levels for populations or communities should be estimated (Suter, 1996). 

In a recent study, Clark et al. have compiled and analyzed measured concentration data of six phthalate esters in seven environmental media including water, sediment, soil, air, dust, food, wastewater, sewage sludge, and rainwater. The data are predominantly from Europe, the United States, Canada, and Japan. The complete database, with references, was presented in a report to the American Chemistry Council. The reported concentrations vary widely as an example, the overall mean concentration of BMP in surface water in Canada (1.40 /rg/1) is three orders of magnitude higher than that found in the U.S. (0.0017 /rg/1). The authors consider that this wide distribution is due to several factors including analytical error, sample contamination, and proximity to a variety of past and present phthalate sources. 

The solubihty of hydrophobic substances in, or their absorbabiUty on suspended particles, on sediments, on biota, or on soil particles can be related to the solubihty of these substances in organic solvents. The solvent -octanol, CH2(CH2)yOH, is a kind of surrogate for many kinds of environmental and physiological organic substances and has become a reference phase for organic phase water partitioning of organic solutes. 

A wide variety of reference materials is now available, covering several different kinds of natural matrix such as food (e.g. milk powder), human tissues (e.g. liver), marine biological materials (e.g. tuna fish) and soils and sediments. The radionuclides of interest cover naturally occurring ones (e.g. Ra), fission products... 

Mineral exploration, the search for economic ore deposits, requires somewhat different reference samples than those used in ore valuation. Soil or sediment and water samples are frequently used in the search when mineralized areas of abundant outcrop or those covered only by thin locally derived overburden are being evaluated. In such cases, it is virtually impossible not to detect the mineralization from an analysis of ore elements in these types of samples. Later, as the mineral deposits closest to the surface were exploited and then played out, new deposits occurred at progressively greater depths, and these sample types were less and less effective as markers in the search (Hoffman 1989). 

The mobility of arsenic compounds in soils is affected by sorp-tion/desorption on/from soil components or co-precipitation with metal ions. The importance of oxides (mainly Fe-oxides) in controlling the mobility and concentration of arsenic in natural environments has been studied for a long time (Livesey and Huang 1981 Frankenberger 2002 and references there in Smedley and Kinniburgh 2002). Because the elements which correlate best with arsenic in soils and sediments are iron, aluminum and manganese, the use of Fe salts (as well as Al and Mn salts) is a common practice in water treatment for the removal of arsenic. The coprecipitation of arsenic with ferric or aluminum hydroxide has been a practical and effective technique to remove this toxic element from polluted waters... 

Bioavailability issues have been reviewed previously (Mihelcic etal. 1993 Boesten 1993 Baveye and Bladon 1999 Ehlers and Luthy 2003). In this review, we discuss specifically the bioavailability of soil- or sediment-sorbed organic contaminants to pollutant-degrading bacteria. Direct uptake of sorbed contaminants is perhaps the most controversial and least understood process. The definition of bioavailability given by Alexander (2000) will be used in this review. The term bioaccessibility encompasses what is immediately available plus that which may become available, whereas bioavailability refers to what is available immediately. 

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