Spatial Variability of Intake Fractions for Canadian Emission Scenarios: A Comparison between Three Resolution Scales

Manneh, Rima; Margni, Manuele; Deschênes, Louise

doi:10.1021/es902983b

Cited by 20 publications

(15 citation statements)

References 21 publications

(29 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Nevertheless, the relative influence of environmental characteristics increases if models are run at a more detailed spatial scale. This was confirmed by, e.g., a case study on Canada, performed by Manneh et al (2010) at three resolution scales, in which variability of the results decrease significantly at higher resolution.…”

Section: Introductionsupporting

confidence: 58%

Spatial differentiation of chemical removal rates from air in life cycle impact assessment

Sala

Dimitar

Pennington

2011

Int J Life Cycle Assess

View full text Add to dashboard Cite

Purpose Spatial differentiation is a topic of increasing interest within life cycle assessment (LCA). For chemicalrelated impacts, in this paper, we evaluate the relative influence of substance properties and of environmental characteristics on the variability in the environmental fate of chemicals using an advanced, spatially resolved model. The goal of this study is to explore spatial distribution and spatial variability of organic chemicals, assessing the variability of the removal rate from air with a multimedia spatially explicit model Multimedia Assessment of Pollutant Pathways in the Environment (MAPPE) Global with a resolution of 1×1°. This provides basis to help identify chemicals for which spatial differentiation will be important in LCAs, including whether differentiation will have added benefits over the use of global generic default values, such as those provided by the USEtox model. Methodology A methodology was developed to explore spatial distribution and spatial variability of the fate of organic chemicals. Firstly, guidelines were developed to assign a hypothetical spatial distribution to chemicals which were clustered on the basis of their physical-chemical properties and persistence. Secondly, a test set of 34 representative organic chemicals was used to run MAPPE Global and USEtox model. The results of MAPPE Global were used to highlight spatial variability of removal rate from air amongst different chemicals and their related patterns of variability. A comparison between USEtox and MAPPE Global removal rates from air was performed for each chemical in order to highlight whether spatial differentiation is relevant for the assessment or not. Results and discussion Hypothetical spatial distribution of chemical fate was assigned to each combination of physical-chemical properties and persistence. Besides, spatial variability of removal rates from air was assessed running MAPPE model for the test set of 34 chemicals. The variability of results spans from less than one to over four orders of magnitude, showing differences in variability for each cluster of chemicals. Furthermore, different patterns of spatial variability are associated to each cluster of chemical as the spatial pattern is driven by a specific component of the overall removal rate. The comparison between MAPPE and USEtox removal rates from air shows that for 14 out of 34 chemicals within the test set, USEtox values are close to the median of the results of MAPPE. For 11 out of 34, USEtox underestimates the removal rate from air and the results are close to the fifth percentile of MAPPE ones. This is mainly related to how wet/dry deposition and gas exchange are accounted in the two models. Conclusions and outlook This work has made further progress towards understanding and implementing how to develop a tailored-made guidance for assessing spatial differentiation in LCA. Results on spatial distribution and spatial variability of chemical are presented as a basis for defining patterns of variability and supporting further development...

show abstract

Section: Introductionsupporting

confidence: 58%

Spatial differentiation of chemical removal rates from air in life cycle impact assessment

Sala

Dimitar

Pennington

2011

Int J Life Cycle Assess

View full text Add to dashboard Cite

show abstract

“…Multimedia fate and transport models have been combined with metrics such as the intake fraction (iF) for large-scale assessments (Bennett et al 2002a). Proximity between chemical releases and exposed populations is emerging as a parameter of key influence for assessing human intake (Manneh et al 2010). Methods for characterizing the degree of exposure intimacy of human populations to manufactured chemicals could improve understanding of exposure pathways and assist in studies that aim to understand biologically relevant exposures (i.e., those associated with a disease) (Cohen Hubal 2009).…”

mentioning

confidence: 99%

Intake to Production Ratio: A Measure of Exposure Intimacy for Manufactured Chemicals

Nazaroff

Weschler

Little

et al. 2012

Environ Health Perspect

View full text Add to dashboard Cite

Background: Limited data are available to assess human exposure to thousands of chemicals currently in commerce. Information that relates human intake of a chemical to its production and use can help inform understanding of mechanisms and pathways that control exposure and support efforts to protect public health.Objectives: We introduce the intake-to-production ratio (IPR) as an economy-wide quantitative indicator of the extent to which chemical production results in human exposure.Methods: The IPR was evaluated as the ratio of two terms: aggregate rate of chemical uptake in a human population (inferred from urinary excretion data) divided by the rate that chemical is produced in or imported into that population’s economy. We used biomonitoring data from the U.S. Centers for Disease Control and Prevention along with chemical manufacturing data reported by the U.S. Environmental Protection Agency, as well as other published data, to estimate the IPR for nine chemicals in the United States. Results are reported in units of parts per million, where 1 ppm indicates 1 g of chemical uptake for every million grams of economy-wide use.Results: Estimated IPR values for the studied compounds span many orders of magnitude from a low of 0.6 ppm for bisphenol A to a high of > 180,000 ppm for methyl paraben. Intermediate results were obtained for five phthalates and two chlorinated aromatic compounds: 120 ppm for butyl benzyl phthalate, 670 ppm for di(2-ethylhexyl) phthalate, 760 ppm for di(n-butyl) phthalate, 1,040 ppm for para-dichlorobenzene, 6,800 ppm for di(isobutyl) phthalate, 7,700 ppm for diethyl phthalate, and 8,000–24,000 ppm (range) for triclosan.Conclusion: The IPR is well suited as an aggregate metric of exposure intensity for characterizing population-level exposure to synthesized chemicals, particularly those that move fairly rapidly from manufacture to human intake and have relatively stable production and intake rates.

show abstract

“…Since human and eco-toxicity occur as regional or local impacts (Potting and Hauschild, 2006;Sedlbauer et al, 2007), recently developed multimedia and multi-pathway models are spatially differentiated in order to provide different impact scores for each regional zone. Spatial differentiation reduces model uncertainty and improves accuracy, precision and confidence in LCA results (Manneh et al, 2010;Potting and Hauschild, 2006;Sleeswijk and Heijungs, 2010). There is therefore a need to customize USEtox for different specific regions of the world in addition to the existing generic continent.…”

Section: Introductionmentioning

confidence: 99%

“…Intra-continental variation has been investigated at several resolutions, including 1 × 1 km grid cells for the MAPPE Europe model Vizcaíno and Pistocchi, 2010), ecological zones with a continental coverage for the BETR North America model (MacLeod et al, 2004), and watershed or sub-watershed resolution for freshwater emissions in various parameterizations of the IMPACT 2002 model (Humbert et al, 2009;Manneh et al, 2010). Depending on the emission location within a given continent, intake fractions vary by 2 to 3 orders of magnitude for emissions to air (MacLeod et al, 2004) and up to 10 orders of magnitude for emissions to water (Manneh et al, 2010), highlighting the necessity of high resolution to reduce intake fraction variability.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Spatial analysis of toxic emissions in LCA: A sub-continental nested USEtox model with freshwater archetypes

Kounina

Margni

Shaked

et al. 2014

Environment International

Self Cite

View full text Add to dashboard Cite

This paper develops continent-specific factors for the USEtox model and analyses the accuracy of different model architectures, spatial scales and archetypes in evaluating toxic impacts, with a focus on freshwater pathways. Inter-continental variation is analysed by comparing chemical fate and intake fractions between sub-continental zones of two life cycle impact assessment models: (1) the nested USEtox model parameterized with sub-continental zones and (2) the spatially differentiated IMPACTWorld model with 17 interconnected sub-continental regions. Substance residence time in water varies by up to two orders of magnitude among the 17 zones assessed with IMPACTWorld and USEtox, and intake fraction varies by up to three orders of magnitude. Despite this variation, the nested USEtox model succeeds in mimicking the results of the spatially differentiated model, with the exception of very persistent volatile pollutants that can be transported to polar regions. Intra-continental variation is analysed by comparing fate and intake fractions modelled with the a-spatial (one box) IMPACT Europe continental model vs. the spatially differentiated version of the same model. Results show that the one box model might overestimate chemical fate and characterisation factors for freshwater eco-toxicity of persistent pollutants by up to three orders of magnitude for point source emissions. Subdividing Europe into three archetypes, based on freshwater residence time (how long it takes water to reach the sea), improves the prediction of fate and intake fractions for point source emissions, bringing them within a factor five compared to the spatial model. We demonstrated that a sub-continental nested model such as USEtox, with continent-specific parameterization complemented with freshwater archetypes, can thus represent inter-and intra-continental spatial variations, whilst minimizing model complexity.

show abstract

Spatial Variability of Intake Fractions for Canadian Emission Scenarios: A Comparison between Three Resolution Scales

Cited by 20 publications

References 21 publications

Spatial differentiation of chemical removal rates from air in life cycle impact assessment

Spatial differentiation of chemical removal rates from air in life cycle impact assessment

Intake to Production Ratio: A Measure of Exposure Intimacy for Manufactured Chemicals

Spatial analysis of toxic emissions in LCA: A sub-continental nested USEtox model with freshwater archetypes

Contact Info

Product

Resources

About