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Delmaar CJE, Schreurs R, Bakker MI, Minnema J, Bokkers BGH. PACEMweb: a tool for aggregate consumer exposure assessment. J Expo Sci Environ Epidemiol 2023; 33:971-979. [PMID: 36522445 PMCID: PMC10733135 DOI: 10.1038/s41370-022-00509-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/05/2022] [Revised: 11/25/2022] [Accepted: 11/25/2022] [Indexed: 06/17/2023]
Abstract
BACKGROUND To ascertain the safe use of chemicals that are used in multiple consumer products, the aggregate human exposure, arising from combined use of multiple consumer products needs to be assessed. OBJECTIVE In this work the Probabilistic Aggregate Consumer Exposure Model (PACEM) is presented and discussed. PACEM is implemented in the publicly available web tool, PACEMweb, for aggregate consumer exposure assessment. METHODS PACEM uses a person-oriented simulation method that is based on realistic product usage information obtained in surveys from several European countries. PACEM evaluates aggregate exposure in a population considering individual use and co-use patterns as well as variation in product composition. Product usage data is included on personal care products (PCPs) and household cleaning products (HCPs). RESULTS PACEM has been implemented in a web tool that supports broad use in research as well as regulatory risk assessment. PACEM has been evaluated in a number of applications, testing and illustrating the advantage of the person-oriented modeling method. Also, PACEM assessments have been evaluated by comparing its results with biomonitoring information. SIGNIFICANCE PACEM enables the assessment of realistic aggregate exposure to chemicals in consumer products. It provides detailed insight into the distribution of exposure in a population as well as products that contribute the most to exposure. This allows for better informed decision making in the risk management of chemicals. IMPACT Realistic assessment of the total, aggregate exposure of consumers to chemicals in consumer products is necessary to guarantee the safe use of chemicals in these products. PACEMweb provides, for the first time, a publicly available tool to assist in realistic aggregate exposure assessment of consumers to chemicals in consumer products.
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Affiliation(s)
- Christiaan J E Delmaar
- National Institute for Public Health and the Environment-RIVM, Bilthoven, The Netherlands.
| | - Roel Schreurs
- National Institute for Public Health and the Environment-RIVM, Bilthoven, The Netherlands
| | - Martine I Bakker
- National Institute for Public Health and the Environment-RIVM, Bilthoven, The Netherlands
| | - Jordi Minnema
- National Institute for Public Health and the Environment-RIVM, Bilthoven, The Netherlands
| | - Bas G H Bokkers
- National Institute for Public Health and the Environment-RIVM, Bilthoven, The Netherlands
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Minnema J, Vandebriel RJ, Boer K, Klerx W, De Jong WH, Delmaar CJE. Physiologically-Based Kinetic Modeling of Intravenously Administered Gold (Au) Nanoparticles. Small 2023; 19:e2207326. [PMID: 36828794 DOI: 10.1002/smll.202207326] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/24/2022] [Revised: 01/27/2023] [Indexed: 05/25/2023]
Abstract
Physiologically-based kinetic (PBK) modeling is a valuable tool to understand the kinetics of nanoparticles (NPs) in vivo. However, estimating PBK parameters remains challenging and commonly requires animal studies. To develop predictive models to estimate PBK parameter values based on NP characteristics, a database containing PBK parameter values and corresponding NP characteristics is needed. As a first step toward this objective, this study estimates PBK parameters for gold NPs (AuNPs) and provides a comparison of two different NPs. Two animal experiments are conducted in which varying doses of AuNPs attached with polyethylene glycol (PEG) are administered intravenously to rats. The resulting Au concentrations are used to estimate PBK model parameters. The parameters are compared with PBK parameters previously estimated for poly(alkyl cyanoacrylate) NPs loaded with cabazitaxel and for LipImage 815. This study shows that a small initial database of PBK parameters collected for three NPs is already sufficient to formulate new hypotheses on NP characteristics that may be predictive of PBK parameter values. Further research should focus on developing a larger database and on developing quantitative models to predict PBK parameter values.
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Affiliation(s)
- Jordi Minnema
- Center for Safety of Substances and Products, National Institute for Public Health and the Environment - RIVM, Bilthoven, BA, 3720, The Netherlands
| | - Rob J Vandebriel
- Center for Health Protection, National Institute for Public Health and the Environment - RIVM, Bilthoven, BA, 3720, The Netherlands
| | - Karin Boer
- Center for Health Protection, National Institute for Public Health and the Environment - RIVM, Bilthoven, BA, 3720, The Netherlands
| | - Walther Klerx
- Center for Health Protection, National Institute for Public Health and the Environment - RIVM, Bilthoven, BA, 3720, The Netherlands
| | - Wim H De Jong
- Center for Health Protection, National Institute for Public Health and the Environment - RIVM, Bilthoven, BA, 3720, The Netherlands
| | - Christiaan J E Delmaar
- Center for Safety of Substances and Products, National Institute for Public Health and the Environment - RIVM, Bilthoven, BA, 3720, The Netherlands
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Wang C, Eichler CMA, Bi C, Delmaar CJE, Xu Y, Little JC. A rapid micro chamber method to measure SVOC emission and transport model parameters. Environ Sci Process Impacts 2023; 25:818-831. [PMID: 36897109 DOI: 10.1039/d2em00507g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
Assessing exposure to semivolatile organic compounds (SVOCs) that are emitted from consumer products and building materials in indoor environments is critical for reducing the associated health risks. Many modeling approaches have been developed for SVOC exposure assessment indoors, including the DustEx webtool. However, the applicability of these tools depends on the availability of model parameters such as the gas-phase concentration at equilibrium with the source material surface, y0, and the surface-air partition coefficient, Ks, both of which are typically determined in chamber experiments. In this study, we compared two types of chamber design, a macro chamber, which downscaled the dimensions of a room to a smaller size with roughly the same surface-to-volume ratio, and a micro chamber, which minimized the sink-to-source surface area ratio to shorten the time required to reach steady state. The results show that the two chambers with different sink-to-source surface area ratios yield comparable steady-state gas- and surface-phase concentrations for a range of plasticizers, while the micro chamber required significantly shorter times to reach steady state. Using y0 and Ks measured with the micro chamber, we conducted indoor exposure assessments for di-n-butyl phthalate (DnBP), di(2-ethylhexyl) phthalate (DEHP) and di(2-ethylhexyl) terephthalate (DEHT) with the updated DustEx webtool. The predicted concentration profiles correspond well with existing measurements and demonstrate the direct applicability of chamber data in exposure assessments.
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Affiliation(s)
- Chunyi Wang
- Department of Civil and Environmental Engineering, Virginia Tech, Blacksburg, VA, USA.
| | - Clara M A Eichler
- Department of Civil and Environmental Engineering, Virginia Tech, Blacksburg, VA, USA.
- Department of Environmental Sciences and Engineering, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Chenyang Bi
- Department of Civil and Environmental Engineering, Virginia Tech, Blacksburg, VA, USA.
| | - Christiaan J E Delmaar
- National Institute for Public Health and the Environment, Center for Safety of Substances and Products, Bilthoven, The Netherlands
| | - Ying Xu
- Department of Building Science, Tsinghua University, Beijing, China
| | - John C Little
- Department of Civil and Environmental Engineering, Virginia Tech, Blacksburg, VA, USA.
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Eichler CMA, Hubal EAC, Xu Y, Cao J, Bi C, Weschler CJ, Salthammer T, Morrison GC, Koivisto AJ, Zhang Y, Mandin C, Wei W, Blondeau P, Poppendieck D, Liu X, Delmaar CJE, Fantke P, Jolliet O, Shin HM, Diamond ML, Shiraiwa M, Zuend A, Hopke PK, von Goetz N, Kulmala M, Little JC. Assessing Human Exposure to SVOCs in Materials, Products, and Articles: A Modular Mechanistic Framework. Environ Sci Technol 2021; 55:25-43. [PMID: 33319994 PMCID: PMC7877794 DOI: 10.1021/acs.est.0c02329] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
A critical review of the current state of knowledge of chemical emissions from indoor sources, partitioning among indoor compartments, and the ensuing indoor exposure leads to a proposal for a modular mechanistic framework for predicting human exposure to semivolatile organic compounds (SVOCs). Mechanistically consistent source emission categories include solid, soft, frequent contact, applied, sprayed, and high temperature sources. Environmental compartments are the gas phase, airborne particles, settled dust, indoor surfaces, and clothing. Identified research needs are the development of dynamic emission models for several of the source emission categories and of estimation strategies for critical model parameters. The modular structure of the framework facilitates subsequent inclusion of new knowledge, other chemical classes of indoor pollutants, and additional mechanistic processes relevant to human exposure indoors. The framework may serve as the foundation for developing an open-source community model to better support collaborative research and improve access for application by stakeholders. Combining exposure estimates derived using this framework with toxicity data for different end points and toxicokinetic mechanisms will accelerate chemical risk prioritization, advance effective chemical management decisions, and protect public health.
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Affiliation(s)
- Clara M A Eichler
- Department of Civil and Environmental Engineering, Virginia Tech, Blacksburg, Virginia 24060, United States
- Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
| | - Elaine A Cohen Hubal
- Office of Research and Development, U.S. EPA, Research Triangle Park, North Carolina 27711, United States
| | - Ying Xu
- Department of Building Science, Tsinghua University, Beijing 100084, China
| | - Jianping Cao
- School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou, Guangdong 510006, China
| | - Chenyang Bi
- Department of Civil and Environmental Engineering, Virginia Tech, Blacksburg, Virginia 24060, United States
| | - Charles J Weschler
- Environmental and Occupational Health Sciences Institute, Rutgers University, Piscataway, New Jersey 08854, United States
- International Centre for Indoor Environment and Energy, Department of Civil Engineering, Technical University of Denmark, Lyngby 2800, Denmark
| | - Tunga Salthammer
- Fraunhofer WKI, Department of Material Analysis and Indoor Chemistry, Braunschweig 38108, Germany
| | - Glenn C Morrison
- Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
| | - Antti Joonas Koivisto
- Institute for Atmospheric and Earth System Research (INAR), University of Helsinki, Helsinki 00014, Finland
| | - Yinping Zhang
- Department of Building Science, Tsinghua University, Beijing 100084, China
| | - Corinne Mandin
- University of Paris-Est, Scientific and Technical Center for Building (CSTB), French Indoor Air Quality Observatory (OQAI), Champs sur Marne 77447, France
| | - Wenjuan Wei
- University of Paris-Est, Scientific and Technical Center for Building (CSTB), French Indoor Air Quality Observatory (OQAI), Champs sur Marne 77447, France
| | - Patrice Blondeau
- Laboratoire des Sciences de l'Ingénieur pour l'Environnement - LaSIE, Université de La Rochelle, La Rochelle 77447, France
| | - Dustin Poppendieck
- Engineering Lab, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, United States
| | - Xiaoyu Liu
- Office of Research and Development, U.S. EPA, Research Triangle Park, North Carolina 27711, United States
| | - Christiaan J E Delmaar
- National Institute for Public Health and the Environment, Center for Safety of Substances and Products, Bilthoven 3720, The Netherlands
| | - Peter Fantke
- Quantitative Sustainability Assessment, Department of Technology, Management and Economics, Technical University of Denmark, Kgs. Lyngby 2800, Denmark
| | - Olivier Jolliet
- Department of Environmental Health Sciences, School of Public Health, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Hyeong-Moo Shin
- Department of Earth and Environmental Sciences, University of Texas at Arlington, Arlington, Texas 76019, United States
| | - Miriam L Diamond
- Department of Earth Sciences, University of Toronto, Toronto, Ontario M5S 3B1, Canada
| | - Manabu Shiraiwa
- Department of Chemistry, University of California, Irvine, California 92697, United States
| | - Andreas Zuend
- Department of Atmospheric and Oceanic Sciences, McGill University, Montreal, Quebec H3A0B9, Canada
| | - Philip K Hopke
- Center for Air Resources Engineering and Science, Clarkson University, Potsdam, New York 13699-5708, United States
- Department of Public Health Sciences, University of Rochester School of Medicine and Dentistry, Rochester, New York 14642, United States
| | | | - Markku Kulmala
- Institute for Atmospheric and Earth System Research (INAR), University of Helsinki, Helsinki 00014, Finland
| | - John C Little
- Department of Civil and Environmental Engineering, Virginia Tech, Blacksburg, Virginia 24060, United States
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Sukiene V, von Goetz N, Gerecke AC, Bakker MI, Delmaar CJE, Hungerbühler K. Direct and Air-Mediated Transfer of Labeled SVOCs from Indoor Sources to Dust. Environ Sci Technol 2017; 51:3269-3277. [PMID: 28240875 DOI: 10.1021/acs.est.6b06051] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Two small-scale field studies were conducted to investigate the transfer of substances from products into dust due to direct and air-mediated transfer. The project focused on semivolatile organic compounds (SVOCs), which are frequently found in and re-emitted from dust. For the field studies, four artificial products containing deuterium-labeled SVOCs (eight phthalates and adipates) were installed in residential indoor environments. Two plastic products were installed vertically to investigate substance transfer due to evaporation into air. One plastic product and a carpet were installed horizontally to investigate the direct transfer from source to dust. A pyrethroid was intentionally released by spraying a commercial spray. Dust samples were collected from the floor, elevated surfaces in the room and the surfaces of the horizontally installed products. We observed that the dust concentrations of substances exclusively transferred via air were similar at different collection sites, but the concentrations of chemicals present in horizontal products were up to 3 orders of magnitude higher in dust deposited on the source. We conclude that direct transfer from source into dust substantially increases the final SVOC concentration in dust in contact with the source, regardless of the vapor pressure of investigated SVOCs, and may lead to larger human exposure.
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Affiliation(s)
- Vilma Sukiene
- Institute for Chemical and Bioengineering, Swiss Federal Institute of Technology, (ETH Zurich) , Vladimir-Prelog-Weg 1, CH-8093 Zurich, Switzerland
- Swiss Federal Laboratories for Material Science and Technology (EMPA), Überlandstrasse 129, CH-8600 Dübendorf, Switzerland
| | - Natalie von Goetz
- Institute for Chemical and Bioengineering, Swiss Federal Institute of Technology, (ETH Zurich) , Vladimir-Prelog-Weg 1, CH-8093 Zurich, Switzerland
| | - Andreas C Gerecke
- Swiss Federal Laboratories for Material Science and Technology (EMPA), Überlandstrasse 129, CH-8600 Dübendorf, Switzerland
| | - Martine I Bakker
- National Institute for Public Health and the Environment (RIVM), P.O. Box 1, 3720 BA Bilthoven, The Netherlands
| | - Christiaan J E Delmaar
- National Institute for Public Health and the Environment (RIVM), P.O. Box 1, 3720 BA Bilthoven, The Netherlands
| | - Konrad Hungerbühler
- Institute for Chemical and Bioengineering, Swiss Federal Institute of Technology, (ETH Zurich) , Vladimir-Prelog-Weg 1, CH-8093 Zurich, Switzerland
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Sukiene V, Gerecke AC, Park YM, Zennegg M, Bakker MI, Delmaar CJE, Hungerbühler K, von Goetz N. Tracking SVOCs' Transfer from Products to Indoor Air and Settled Dust with Deuterium-Labeled Substances. Environ Sci Technol 2016; 50:4296-303. [PMID: 27019300 DOI: 10.1021/acs.est.5b05906] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Semivolatile organic compounds (SVOCs) can be released from products and distributed in the indoor environment, including air and dust. However, the mechanisms and the extent of substance transfer into air and dust are not well understood. Therefore, in a small-scale field study the transfer of nine SVOCs was investigated: Four artificial consumer products were doped with eight deuterium-labeled plasticizers (phthalates and adipates) and installed in five homes to investigate the emission processes of evaporation, abrasion, and direct transfer. Intentional release was studied with a commercial spray containing a pyrethroid. During the 12 week study, indoor air and settled dust samples were collected and analyzed. On the basis of our measurement results, we conclude that the octanol-air partitioning coefficient Koa is a major determinant for the substance transfer into either air or dust: A high Koa implies that the substance is more likely to be found in dust than in air. The emission process also plays a role: For spraying, we found higher dust and air concentrations than for evaporation. In contrast, apartment parameters like air exchange rate or temperature had just a minor influence. Another important mechanistic finding was that although transfer from product to dust currently is postulated to be mostly mediated by air, direct transport from product to dust on the product surface was also observed.
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Affiliation(s)
- Vilma Sukiene
- Institute for Chemical and Bioengineering, Swiss Federal Institute of Technology (ETH Zurich) , Vladimir-Prelog-Weg 1, CH-8093 Zurich, Switzerland
- Swiss Federal Laboratories for Material Science and Technology (EMPA) , Überlandstrasse 129, CH-8600 Dübendorf, Switzerland
| | - Andreas C Gerecke
- Swiss Federal Laboratories for Material Science and Technology (EMPA) , Überlandstrasse 129, CH-8600 Dübendorf, Switzerland
| | - Yu-Mi Park
- Environmental Research Complex, National Institute of Environmental Research (NIER) , Hwangyong-ro 42, Seo-gu, Incheon 404-708, Republic of Korea
| | - Markus Zennegg
- Swiss Federal Laboratories for Material Science and Technology (EMPA) , Überlandstrasse 129, CH-8600 Dübendorf, Switzerland
| | - Martine I Bakker
- National Institute for Public Health and the Environment (RIVM) , P.O. Box 1, 3720 BA Bilthoven, The Netherlands
| | - Christiaan J E Delmaar
- National Institute for Public Health and the Environment (RIVM) , P.O. Box 1, 3720 BA Bilthoven, The Netherlands
| | - Konrad Hungerbühler
- Institute for Chemical and Bioengineering, Swiss Federal Institute of Technology (ETH Zurich) , Vladimir-Prelog-Weg 1, CH-8093 Zurich, Switzerland
| | - Natalie von Goetz
- Institute for Chemical and Bioengineering, Swiss Federal Institute of Technology (ETH Zurich) , Vladimir-Prelog-Weg 1, CH-8093 Zurich, Switzerland
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Dudzina T, Delmaar CJE, Biesterbos JWH, Bakker MI, Bokkers BGH, Scheepers PTJ, van Engelen JGM, Hungerbuehler K, von Goetz N. The probabilistic aggregate consumer exposure model (PACEM): validation and comparison to a lower-tier assessment for the cyclic siloxane D5. Environ Int 2015; 79:8-16. [PMID: 25768720 DOI: 10.1016/j.envint.2015.03.006] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/28/2014] [Revised: 02/02/2015] [Accepted: 03/04/2015] [Indexed: 05/03/2023]
Abstract
Current practice of chemical risk assessment for consumer product ingredients still rarely exercises the aggregation of multi-source exposure. However, focusing on a single dominant source/pathway combination may lead to a significant underestimation of the risk for substances present in numerous consumer products, which often are used simultaneously. Moreover, in most cases complex multi-route exposure scenarios also need to be accounted for. This paper introduces and evaluates the performance of the Probabilistic Aggregate Consumer Exposure Model (PACEM) applied in the context of a tiered approach to exposure assessment for ingredients in cosmetics and personal care products (C&PCPs) using decamethylcyclopentasiloxane (D5) as a worked example. It is demonstrated that PACEM predicts a more realistic, but still conservative aggregate exposure within the Dutch adult population when compared to a deterministic point estimate obtained in a lower tier screening assessment. An overall validation of PACEM is performed by quantitatively relating and comparing its estimates to currently available human biomonitoring and environmental sampling data. Moderate (by maximum one order of magnitude) overestimation of exposure is observed due to a justified conservatism built into the model structure, resulting in the tool being suitable for risk assessment.
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Affiliation(s)
- Tatsiana Dudzina
- Institute for Chemical and Bioengineering, ETH Zurich Swiss Federal Institute of Technology, Vladimir-Prelog-Weg 1, 8093 Zurich, Switzerland
| | - Christiaan J E Delmaar
- National Institute for Public Health and the Environment (RIVM), P.O. Box 1, Bilthoven, 3720 BA, The Netherlands
| | | | - Martine I Bakker
- National Institute for Public Health and the Environment (RIVM), P.O. Box 1, Bilthoven, 3720 BA, The Netherlands
| | - Bas G H Bokkers
- National Institute for Public Health and the Environment (RIVM), P.O. Box 1, Bilthoven, 3720 BA, The Netherlands
| | - Paul T J Scheepers
- Radboud UMC, Department for Health Evidence (133), P.O. Box 9101, 6500 HB Nijmegen, The Netherlands
| | - Jacqueline G M van Engelen
- National Institute for Public Health and the Environment (RIVM), P.O. Box 1, Bilthoven, 3720 BA, The Netherlands
| | - Konrad Hungerbuehler
- Institute for Chemical and Bioengineering, ETH Zurich Swiss Federal Institute of Technology, Vladimir-Prelog-Weg 1, 8093 Zurich, Switzerland
| | - Natalie von Goetz
- Institute for Chemical and Bioengineering, ETH Zurich Swiss Federal Institute of Technology, Vladimir-Prelog-Weg 1, 8093 Zurich, Switzerland.
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Delmaar CJE, Peijnenburg WJGM, Oomen AG, Chen J, de Jong WH, Sips AJAM, Wang Z, Park MVDZ. A practical approach to determine dose metrics for nanomaterials. Environ Toxicol Chem 2015; 34:1015-1022. [PMID: 25565198 DOI: 10.1002/etc.2878] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/24/2014] [Revised: 12/14/2014] [Accepted: 12/31/2014] [Indexed: 05/29/2023]
Abstract
Traditionally, administered mass is used to describe doses of conventional chemical substances in toxicity studies. For deriving toxic doses of nanomaterials, mass and chemical composition alone may not adequately describe the dose, because particles with the same chemical composition can have completely different toxic mass doses depending on properties such as particle size. Other dose metrics such as particle number, volume, or surface area have been suggested, but consensus is lacking. The discussion regarding the most adequate dose metric for nanomaterials clearly needs a systematic, unbiased approach to determine the most appropriate dose metric for nanomaterials. In the present study, the authors propose such an approach and apply it to results from in vitro and in vivo experiments with silver and silica nanomaterials. The proposed approach is shown to provide a convenient tool to systematically investigate and interpret dose metrics of nanomaterials. Recommendations for study designs aimed at investigating dose metrics are provided.
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Gosens I, Delmaar CJE, ter Burg W, de Heer C, Schuur AG. Aggregate exposure approaches for parabens in personal care products: a case assessment for children between 0 and 3 years old. J Expo Sci Environ Epidemiol 2014; 24:208-14. [PMID: 23801276 PMCID: PMC3929779 DOI: 10.1038/jes.2013.33] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/23/2012] [Accepted: 04/02/2013] [Indexed: 05/20/2023]
Abstract
In the risk assessment of chemical substances, aggregation of exposure to a substance from different sources via different pathways is not common practice. Focusing the exposure assessment on a substance from a single source can lead to a significant underestimation of the risk. To gain more insight on how to perform an aggregate exposure assessment, we applied a deterministic (tier 1) and a person-oriented probabilistic approach (tier 2) for exposure to the four most common parabens through personal care products in children between 0 and 3 years old. Following a deterministic approach, a worst-case exposure estimate is calculated for methyl-, ethyl-, propyl- and butylparaben. As an illustration for risk assessment, Margins of Exposure (MoE) are calculated. These are 991 and 4966 for methyl- and ethylparaben, and 8 and 10 for propyl- and butylparaben, respectively. In tier 2, more detailed information on product use has been obtained from a small survey on product use of consumers. A probabilistic exposure assessment is performed to estimate the variability and uncertainty of exposure in a population. Results show that the internal exposure for each paraben is below the level determined in tier 1. However, for propyl- and butylparaben, the percentile of the population with an exposure probability above the assumed "safe" MoE of 100, is 13% and 7%, respectively. In conclusion, a tier 1 approach can be performed using simple equations and default point estimates, and serves as a starting point for exposure and risk assessment. If refinement is warranted, the more data demanding person-oriented probabilistic approach should be used. This probabilistic approach results in a more realistic exposure estimate, including the uncertainty, and allows determining the main drivers of exposure. Furthermore, it allows to estimate the percentage of the population for which the exposure is likely to be above a specific value.
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Affiliation(s)
- Ilse Gosens
- National Institute for Public Health and the Environment (RIVM), Bilthoven, The Netherlands
| | - Christiaan J E Delmaar
- National Institute for Public Health and the Environment (RIVM), Bilthoven, The Netherlands
| | - Wouter ter Burg
- National Institute for Public Health and the Environment (RIVM), Bilthoven, The Netherlands
| | - Cees de Heer
- National Institute for Public Health and the Environment (RIVM), Bilthoven, The Netherlands
| | - A Gerlienke Schuur
- National Institute for Public Health and the Environment (RIVM), Bilthoven, The Netherlands
- National Institute for Public Health and the Environment, P.O. box 1, Bilthoven 3720 BA, The Netherlands. Tel.: +31 302743752. Fax: +31 2744475. E-mail:
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Young BM, Tulve NS, Egeghy PP, Driver JH, Zartarian VG, Johnston JE, Delmaar CJE, Evans JJ, Smith LA, Glen G, Lunchick C, Ross JH, Xue J, Barnekow DE. Comparison of four probabilistic models (CARES(®), Calendex™, ConsExpo, and SHEDS) to estimate aggregate residential exposures to pesticides. J Expo Sci Environ Epidemiol 2012; 22:522-532. [PMID: 22781436 DOI: 10.1038/jes.2012.54] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/01/2011] [Accepted: 04/19/2012] [Indexed: 06/01/2023]
Abstract
Two deterministic models (US EPA's Office of Pesticide Programs Residential Standard Operating Procedures (OPP Residential SOPs) and Draft Protocol for Measuring Children's Non-Occupational Exposure to Pesticides by all Relevant Pathways (Draft Protocol)) and four probabilistic models (CARES(®), Calendex™, ConsExpo, and SHEDS) were used to estimate aggregate residential exposures to pesticides. The route-specific exposure estimates for young children (2-5 years) generated by each model were compared to evaluate data inputs, algorithms, and underlying assumptions. Three indoor exposure scenarios were considered: crack and crevice, fogger, and flying insect killer. Dermal exposure estimates from the OPP Residential SOPs and the Draft Protocol were 4.75 and 2.37 mg/kg/day (crack and crevice scenario) and 0.73 and 0.36 mg/kg/day (fogger), respectively. The dermal exposure estimates (99th percentile) for the crack and crevice scenario were 16.52, 12.82, 3.57, and 3.30 mg/kg/day for CARES, Calendex, SHEDS, and ConsExpo, respectively. Dermal exposure estimates for the fogger scenario from CARES and Calendex (1.50 and 1.47 mg/kg/day, respectively) were slightly higher than those from SHEDS and ConsExpo (0.74 and 0.55 mg/kg/day, respectively). The ConsExpo derived non-dietary ingestion estimates (99th percentile) under these two scenarios were higher than those from SHEDS, CARES, and Calendex. All models produced extremely low exposure estimates for the flying insect killer scenario. Using similar data inputs, the model estimates by route for these scenarios were consistent and comparable. Most of the models predicted exposures within a factor of 5 at the 50th and 99th percentiles. The differences identified are explained by activity assumptions, input distributions, and exposure algorithms.
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Affiliation(s)
- Bruce M Young
- Bayer CropScience, Research Triangle Park, North Carolina, USA
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