Dataset Information

Prioritizing chemicals and data requirements for screening-level exposure and risk assessment.

ABSTRACT:

Background

Scientists and regulatory agencies strive to identify chemicals that may cause harmful effects to humans and the environment; however, prioritization is challenging because of the large number of chemicals requiring evaluation and limited data and resources.

Objectives

We aimed to prioritize chemicals for exposure and exposure potential and obtain a quantitative perspective on research needs to better address uncertainty in screening assessments.

Methods

We used a multimedia mass balance model to prioritize > 12,000 organic chemicals using four far-field human exposure metrics. The propagation of variance (uncertainty) in key chemical information used as model input for calculating exposure metrics was quantified.

Results

Modeled human concentrations and intake rates span approximately 17 and 15 orders of magnitude, respectively. Estimates of exposure potential using human concentrations and a unit emission rate span approximately 13 orders of magnitude, and intake fractions span 7 orders of magnitude. The actual chemical emission rate contributes the greatest variance (uncertainty) in exposure estimates. The human biotransformation half-life is the second greatest source of uncertainty in estimated concentrations. In general, biotransformation and biodegradation half-lives are greater sources of uncertainty in modeled exposure and exposure potential than chemical partition coefficients.

Conclusions

Mechanistic exposure modeling is suitable for screening and prioritizing large numbers of chemicals. By including uncertainty analysis and uncertainty in chemical information in the exposure estimates, these methods can help identify and address the important sources of uncertainty in human exposure and risk assessment in a systematic manner.

SUBMITTER: Arnot JA

PROVIDER: S-EPMC3556628 | biostudies-literature | 2012 Nov

REPOSITORIES: biostudies-literature

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Publications

Prioritizing chemicals and data requirements for screening-level exposure and risk assessment.

Arnot Jon A JA Brown Trevor N TN Wania Frank F Breivik Knut K McLachlan Michael S MS

Environmental health perspectives 20120920 11

<h4>Background</h4>Scientists and regulatory agencies strive to identify chemicals that may cause harmful effects to humans and the environment; however, prioritization is challenging because of the large number of chemicals requiring evaluation and limited data and resources.<h4>Objectives</h4>We aimed to prioritize chemicals for exposure and exposure potential and obtain a quantitative perspective on research needs to better address uncertainty in screening assessments.<h4>Methods</h4>We used ...[more]

PMID: 23008278

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Dataset Information

Prioritizing chemicals and data requirements for screening-level exposure and risk assessment.

Background

Objectives

Methods

Results

Conclusions

Publications

Prioritizing chemicals and data requirements for screening-level exposure and risk assessment.

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