Tighe, Matthew; Pollino, Carmel A; Wilson, Susan C

Author(s)

Tighe, Matthew

Pollino, Carmel A

Wilson, Susan C

Publication Date

2013

Abstract

A tiered approach to contamination exposure assessment is currently adopted in many countries. Increasing the site-specific information in exposure assessments is generally recommended when guideline values for contaminants in soil are exceeded. This work details a Bayesian Network (BN) approach to developing a site-specific environmental exposure assessment that focuses on the simple mapping and assessment of assumptions and the effect of new data on assessment outcomes. The BN approach was applied to a floodplain system in New South Wales, Australia, where site-specific information about elevated antimony (Sb) concentrations and distribution in soils was available. Guidelines for exposure assessment in Australia are used as a template for this site, although the approach is generic. The BN-based assessment used an iterative approach starting with limited soil Sb data (41 samples ranging from 0 to 18 mg kg⁻¹ Sb) and extending the model with more detailed Sb data (145 samples ranging from 0 to 40 mg kg⁻¹ Sb). The analyses identified dominant exposure pathways and assessed the sensitivity of these pathways to changes in assumptions and the level of site-specific information available. In particular, there was a 10.8% probability of exceeding the tolerable daily intake of Sb in the case study when the limited soil Sb data was used, which increased to 26.2% with the more detailed sampling regime. There was also a 47% decrease in the probability of overexposure to Sb when the dermal bioavailability of arsenic (a similar metalloid) was used as a surrogate measure instead of a default bioavailability of 100%. We conclude that the BN approach to soil exposure assessment has merit both in the context of Australian and international soil exposure assessments.

Citation

Journal of Environmental Management, v.123, p. 68-76

ISSN

1095-8630

0301-4797

Link

https://hdl.handle.net/1959.11/12456

Publisher

Elsevier BV

Title

Bayesian Networks as a screening tool for exposure assessment

Type of document

Journal Article

Entity Type

Publication

Author(s)	Tighe, Matthew Pollino, Carmel A Wilson, Susan C
Publication Date	2013
Abstract	A tiered approach to contamination exposure assessment is currently adopted in many countries. Increasing the site-specific information in exposure assessments is generally recommended when guideline values for contaminants in soil are exceeded. This work details a Bayesian Network (BN) approach to developing a site-specific environmental exposure assessment that focuses on the simple mapping and assessment of assumptions and the effect of new data on assessment outcomes. The BN approach was applied to a floodplain system in New South Wales, Australia, where site-specific information about elevated antimony (Sb) concentrations and distribution in soils was available. Guidelines for exposure assessment in Australia are used as a template for this site, although the approach is generic. The BN-based assessment used an iterative approach starting with limited soil Sb data (41 samples ranging from 0 to 18 mg kg⁻¹ Sb) and extending the model with more detailed Sb data (145 samples ranging from 0 to 40 mg kg⁻¹ Sb). The analyses identified dominant exposure pathways and assessed the sensitivity of these pathways to changes in assumptions and the level of site-specific information available. In particular, there was a 10.8% probability of exceeding the tolerable daily intake of Sb in the case study when the limited soil Sb data was used, which increased to 26.2% with the more detailed sampling regime. There was also a 47% decrease in the probability of overexposure to Sb when the dermal bioavailability of arsenic (a similar metalloid) was used as a surrogate measure instead of a default bioavailability of 100%. We conclude that the BN approach to soil exposure assessment has merit both in the context of Australian and international soil exposure assessments.
Citation	Journal of Environmental Management, v.123, p. 68-76
ISSN	1095-8630 0301-4797
Link	https://hdl.handle.net/1959.11/12456
Publisher	Elsevier BV
Title	Bayesian Networks as a screening tool for exposure assessment
Type of document	Journal Article
Entity Type	Publication

Bayesian Networks as a screening tool for exposure assessment

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