Comparison of groundwater and surface water for patterns and levels of contamination by toxic substances

Page, G. William

doi:10.1021/es00094a008

Cited by 100 publications

(44 citation statements)

References 7 publications

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“…Arsenic concentrations in groundwater average about 0.1-2 μg/L, but in areas with volcanic rock or sulfide mineral deposits the concentrations can range up to 3,400 μg/L (Page, 1981;Welch et al, 1988;Robertson, 1989). In some mining areas arsenic concentrations up to 48, 000 μg/L have been reported.…”

Section: Watermentioning

confidence: 99%

Scientific Opinion on Arsenic in Food

2009

EFSA Journal

877

220

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The EFSA Panel on Contaminants in the Food Chain (CONTAM Panel) assessed the risks to human health related to the presence of arsenic in food. More than 100,000 occurrence data on arsenic in food were considered with approximately 98 % reported as total arsenic. Making a number of assumptions for the contribution of inorganic arsenic to total arsenic, the inorganic arsenic exposure from food and water across 19 European countries, using lower bound and upper bound concentrations, has been estimated to range from 0.13 to 0.56 µg/kg bodyweight (b.w.) per day for average consumers, and from 0.37 to 1.22 µg/kg b.w. per day for 95 th percentile consumers. Dietary exposure to inorganic arsenic for children under three years of age is in general estimated to be from 2 to 3-fold that of adults. The CONTAM Panel concluded that the provisional tolerable weekly intake (PTWI) of 15 µg/kg b.w. established by the Joint FAO/WHO Expert Committee on Food Additives (JECFA) is no longer appropriate as data had shown that inorganic arsenic causes cancer of the lung and urinary bladder in addition to skin, and that a range of adverse effects had been reported at exposures lower than those reviewed by the JECFA. The CONTAM Panel modelled the dose-response data from key for providing consumption information and calculating exposure, the partners of the EFSA project on the "Individual food consumption data and exposure" coordinated by Ghent University (Department of Public Health, University Hospital, Ghent University, Belgium), and RIKILT (Institute of Food Safety, Wageningen, The Netherlands) for the accessibility of the exposure assessment tools. 4 Table of contents shows now the fourth level of subheadings. 5 An error in the interpretation of the total number of the population in the study of Rahman et al. (2006a) was discovered (Table 41). The BMDL was recalculated and as a consequence it was not considered a potential reference point. The text in the opinion, Table 43 and Appendix were revised accordingly. In addition, the header of the "total number of cases" was replaced by "total number of individuals" in Tables 40-42 and the erroneous units were corrected to µg/L in the text below SUMMARYArsenic is a metalloid that occurs in different inorganic and organic forms, which are found in the environment both from natural occurrence and from anthropogenic activity. The inorganic forms of arsenic are more toxic as compared to the organic arsenic but so far most of the occurrence data in food collected in the framework of official food control are still reported as total arsenic without differentiating the various arsenic species. The need for speciation data is evident because several investigations have shown that especially in seafood most of the arsenic is present in organic forms that are less toxic. Consequently, a risk assessment not taking into account the different species but considering total arsenic as being present exclusively as inorganic arsenic would lead to a considerable overestimation of the health risk rel...

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Section: Watermentioning

confidence: 99%

Scientific Opinion on Arsenic in Food

2009

EFSA Journal

877

220

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“…= evaporative heat loss from soil surface; (11) At the air-soil interface, the boundary condition is given as:…”

Section: Simulating Transport Of Pcbs In Unsaturated and Saturated Soilsmentioning

confidence: 99%

“…Until recently, a much less expensive option was subsurface burial. Unfortunately, this disposal method has been the source of widespread contamination of surface and groundwaters (11). Even in a well-designed subsurface burial site, protective liners and catchment systems will be breached and PCBs will gradually migrate into groundwaters.…”

Section: Introductionmentioning

confidence: 99%

Waste Disposal Technologies for Polychlorinated Biphenyls

Piver¹,

Lindstrom²

1985

Environmental Health Perspectives

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Improper practices in the disposal of polychlorinated biphenyl (PCB) wastes by land burial, chemical means and incineration distribute these chemicals and related compounds such as polychlorinated dibenzofurans (PCDFs) and polychlorinated dibenzodioxins (PCDDs) throughout the environment. The complete range of methods for disposal that have been proposed and are in use are examined and analyzed, with emphasis given to the two most commonly used methods: land burial and incineration.The understanding of aquifer contamination caused by migration of PCBs from subsurface burial sites requires a description of the physical, chemical and biological processes governing transport in unsaturated and saturated soils. For this purpose, a model is developed and solved for different soil conditions and external driving functions. The model couples together the fundamental transport phenomena for heat, mass, and moisture flow within the soil.To rehabilitate a contaminated aquifer, contaminated groundwaters are withdrawn through drainage wells, PCBs are extracted with solvents or activated carbon and treated by chemical, photochemical or thermal methods. The chemical and photochemical methods are reviewed, but primary emphasis is devoted to the use of incineration as the preferred method of disposal. After discussing the formation of PCDFs and PCDDs during combustion from chloroaromatic, chloroaliphatic, as well as organic and inorganic chloride precursors, performance characteristics of different thermal destructors are presented and analyzed. To understand how this information can be used, basic design equations are developed from governing heat and mass balances that can be applied to the construction of incinerators capable of more than 99.99% destruction with minimal to nondetectable levels of PCDFs and PCDDs.

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“…Copper concentrations may fluctuate in aquatic systems depending on the level of input from wastewater disposal, aquacultural use, marina activity, accidental spills, remediation e#orts, or increased surface run-o# following storms (ATSDR, 1990;Hall et al, 1988;Parrish & Uchrin, 1990). Environmental levels of copper surface water range from 0·5 to 1000 g/l (median 10 g/l) (Bergqvist & Sundbom, 1980;Page, 1981). In Chesapeake Bay, U.S.A., an estuary with numerous harbours, marinas, and a shipping channel, dissolved copper concentrations ranged from <10 to 80 g/l with a mean value of 11·7 g/l (Hall et al, 1988).…”

Section: Introductionmentioning

confidence: 99%