TerraGraphics Environmental Engineering Inc.

Moscow, ID, United States

TerraGraphics Environmental Engineering Inc.

Moscow, ID, United States
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von Lindern I.,TerraGraphics Environmental Engineering Inc. | Spalinger S.,TerraGraphics Environmental Engineering Inc. | Stifelman M.L.,U.S. Environmental Protection Agency | Stanek L.W.,U.S. Environmental Protection Agency | Bartrem C.,TerraGraphics Environmental Engineering Inc.
Environmental Health Perspectives | Year: 2016

Background: Soil/dust ingestion rates are important variables in assessing children’s health risks in contaminated environments. Current estimates are based largely on soil tracer methodology, which is limited by analytical uncertainty, small sample size, and short study duration. Objectives: The objective was to estimate site-specific soil/dust ingestion rates through reevaluation of the lead absorption dose–response relationship using new bioavailability data from the Bunker Hill Mining and Metallurgical Complex Superfund Site (BHSS) in Idaho, USA. Methods: The U.S. Environmental Protection Agency (EPA) in vitro bioavailability methodology was applied to archived BHSS soil and dust samples. Using age-specific biokinetic slope factors, we related bioavailable lead from these sources to children’s blood lead levels (BLLs) monitored during cleanup from 1988 through 2002. Quantitative regression analyses and exposure assessment guidance were used to develop candidate soil/dust source partition scenarios estimating lead intake, allowing estimation of age-specific soil/dust ingestion rates. These ingestion rate and bioavailability estimates were simultaneously applied to the U.S. EPA Integrated Exposure Uptake Biokinetic Model for Lead in Children to determine those combinations best approximating observed BLLs. Results: Absolute soil and house dust bioavailability averaged 33% (SD ± 4%) and 28% (SD ± 6%), respectively. Estimated BHSS age-specific soil/dust ingestion rates are 86–94 mg/day for 6-month- to 2-year-old children and 51–67 mg/day for 2- to 9-year-old children. Conclusions: Soil/dust ingestion rate estimates for 1- to 9-year-old children at the BHSS are lower than those commonly used in human health risk assessment. A substantial component of children’s exposure comes from sources beyond the immediate home environment. © 2016, Public Health Services, US Dept of Health and Human Services. All rights reserved.


Vernon Jr. D.K.,TerraGraphics Environmental Engineering Inc.
Tailings and Mine Waste'10 - Proceedings of the 14th International Conference on Tailings and Mine Waste | Year: 2011

The East Mission Flats Repository was designed to dispose of metals contaminated soils and debris wastes. Several of the engineering design challenges included repository configuration to reduce visual impacts; access analysis to reduce impacts to local roads; stormwater management integrated into the phased construction to retain sediment; slope stability for waste configuration and placement; evapotranspiration cover to reduce precipitation infiltration through the waste; and groundwater quality protection. © 2011 Taylor & Francis Group, London.


Woolston J.S.,TerraGraphics Environmental Engineering Inc.
Tailings and Mine Waste'10 - Proceedings of the 14th International Conference on Tailings and Mine Waste | Year: 2011

To support soil cleanup and site remediation activities at the Bunker Hill Superfund Site (BHSS) in northern Idaho, contaminated soils are removed from residential yards and stored in repositories. With a limited supply of suitable land available for site selection, former tailings ponds and tailings-covered ground are used as repositories. At the Big Creek Repository (BCR) in the BHSS, design methods developed from the results of in-situ and laboratory testing and analysis of the physical properties of mine and mill tailings have been used to design, construct, and expand this repository. In 2004 the engineering design properties were developed for the BCR as a result of extensive geotechnical testing of the foundation materials. These properties were retested to demonstrate how the strength properties change as the repository is loaded. The data collected at BCR are being successfully applied to the expansion of the BCR and the design of other repositories. © 2011 Taylor & Francis Group, London.

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