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Schacht CM, Meade AE, Bernstein AS, Prasad B, Schlosser PM, Tran HT, Kapraun DF. Evaluating the impact of anatomical and physiological variability on human equivalent doses using PBPK models. Toxicol Sci 2024; 200:241-264. [PMID: 38796678 DOI: 10.1093/toxsci/kfae067] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/28/2024] Open
Abstract
Addressing human anatomical and physiological variability is a crucial component of human health risk assessment of chemicals. Experts have recommended probabilistic chemical risk assessment paradigms in which distributional adjustment factors are used to account for various sources of uncertainty and variability, including variability in the pharmacokinetic behavior of a given substance in different humans. In practice, convenient assumptions about the distribution forms of adjustment factors and human equivalent doses (HEDs) are often used. Parameters such as tissue volumes and blood flows are likewise often assumed to be lognormally or normally distributed without evaluating empirical data for consistency with these forms. In this work, we performed dosimetric extrapolations using physiologically based pharmacokinetic (PBPK) models for dichloromethane (DCM) and chloroform that incorporate uncertainty and variability to determine if the HEDs associated with such extrapolations are approximately lognormal and how they depend on the underlying distribution shapes chosen to represent model parameters. We accounted for uncertainty and variability in PBPK model parameters by randomly drawing their values from a variety of distribution types. We then performed reverse dosimetry to calculate HEDs based on animal points of departure for each set of sampled parameters. Corresponding samples of HEDs were tested to determine the impact of input parameter distributions on their central tendencies, extreme percentiles, and degree of conformance to lognormality. This work demonstrates that the measurable attributes of human variability should be considered more carefully and that generalized assumptions about parameter distribution shapes may lead to inaccurate estimates of extreme percentiles of HEDs.
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Affiliation(s)
- Celia M Schacht
- Center for Public Health and Environmental Assessment, Office of Research and Development, U.S. Environmental Protection Agency, Durham, North Carolina 27711, USA
| | - Annabel E Meade
- Applied Research Associates, Inc. Raleigh, North Carolina 27615, USA
| | - Amanda S Bernstein
- Center for Public Health and Environmental Assessment, Office of Research and Development, U.S. Environmental Protection Agency, Durham, North Carolina 27711, USA
- Oak Ridge Institute for Science and Education, Oak Ridge, Tennessee 37830, USA
| | | | - Paul M Schlosser
- Center for Public Health and Environmental Assessment, Office of Research and Development, U.S. Environmental Protection Agency, Durham, North Carolina 27711, USA
| | - Hien T Tran
- Center for Research in Scientific Computation, NC State University, Raleigh, North Carolina 27607, USA
| | - Dustin F Kapraun
- Center for Public Health and Environmental Assessment, Office of Research and Development, U.S. Environmental Protection Agency, Durham, North Carolina 27711, USA
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2
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Tucci M, Fernández-Verdejo D, Resitano M, Ciacia P, Guisasola A, Blánquez P, Marco-Urrea E, Cruz Viggi C, Matturro B, Crognale S, Aulenta F. Toluene-driven anaerobic biodegradation of chloroform in a continuous-flow bioelectrochemical reactor. CHEMOSPHERE 2023; 338:139467. [PMID: 37437617 DOI: 10.1016/j.chemosphere.2023.139467] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Revised: 06/12/2023] [Accepted: 07/09/2023] [Indexed: 07/14/2023]
Abstract
Subsurface co-contamination by multiple pollutants can be challenging for the design of bioremediation strategies since it may require promoting different and often antagonistic degradation pathways. Here, we investigated the simultaneous degradation of toluene and chloroform (CF) in a continuous-flow anaerobic bioelectrochemical reactor. As a result, 47 μmol L-1 d-1 of toluene and 60 μmol L-1 d-1 of CF were concurrently removed, when the anode was polarized at +0.4 V vs. Standard Hydrogen Electrode (SHE). Analysis of the microbial community structure and key functional genes allowed to identify the involved degradation pathways. Interestingly, when acetate was supplied along with toluene, to simulate the impact of a readily biodegradable substrate on process performance, toluene degradation was adversely affected, likely due to competitive inhibition effects. Overall, this study proved the efficacy of the developed bioelectrochemical system in simultaneously treating multiple groundwater contaminants, paving the way for the application in real-world scenarios.
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Affiliation(s)
- Matteo Tucci
- Water Research Institute (IRSA), National Research Council (CNR), Via Salaria km 29.300, 00015, Monterotondo, RM, Italy
| | - David Fernández-Verdejo
- Biorem UAB, Department of Chemical, Biological and Environmental Engineering, School of Engineering, Universitat Autònoma de Barcelona, 08193, Bellaterra, Barcelona, Spain
| | - Marco Resitano
- Water Research Institute (IRSA), National Research Council (CNR), Via Salaria km 29.300, 00015, Monterotondo, RM, Italy
| | - Pamela Ciacia
- Water Research Institute (IRSA), National Research Council (CNR), Via Salaria km 29.300, 00015, Monterotondo, RM, Italy
| | - Albert Guisasola
- GENOCOV, Department of Chemical, Biological and Environmental Engineering, School of Engineering, Universitat Autònoma de Barcelona, 08193, Bellaterra, Barcelona, Spain
| | - Paqui Blánquez
- Biorem UAB, Department of Chemical, Biological and Environmental Engineering, School of Engineering, Universitat Autònoma de Barcelona, 08193, Bellaterra, Barcelona, Spain
| | - Ernest Marco-Urrea
- Biorem UAB, Department of Chemical, Biological and Environmental Engineering, School of Engineering, Universitat Autònoma de Barcelona, 08193, Bellaterra, Barcelona, Spain
| | - Carolina Cruz Viggi
- Water Research Institute (IRSA), National Research Council (CNR), Via Salaria km 29.300, 00015, Monterotondo, RM, Italy
| | - Bruna Matturro
- Water Research Institute (IRSA), National Research Council (CNR), Via Salaria km 29.300, 00015, Monterotondo, RM, Italy; National Biodiversity Future Center (NBFC), Palermo, Italy
| | - Simona Crognale
- Water Research Institute (IRSA), National Research Council (CNR), Via Salaria km 29.300, 00015, Monterotondo, RM, Italy; National Biodiversity Future Center (NBFC), Palermo, Italy
| | - Federico Aulenta
- Water Research Institute (IRSA), National Research Council (CNR), Via Salaria km 29.300, 00015, Monterotondo, RM, Italy; National Biodiversity Future Center (NBFC), Palermo, Italy.
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3
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Lin N, Kwarteng L, Godwin C, Warner S, Robins T, Arko-Mensah J, Fobil JN, Batterman S. Airborne volatile organic compounds at an e-waste site in Ghana: Source apportionment, exposure and health risks. JOURNAL OF HAZARDOUS MATERIALS 2021; 419:126353. [PMID: 34175701 PMCID: PMC9925107 DOI: 10.1016/j.jhazmat.2021.126353] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Revised: 06/05/2021] [Accepted: 06/07/2021] [Indexed: 06/01/2023]
Abstract
Informal e-waste recycling processes emit various air pollutants. While there are a number of pollutants of concern, little information exists on volatile organic compounds (VOCs) releases at e-waste sites. To assess occupational exposures and estimate health risks, we measured VOC levels at the Agbogbloshie e-waste site in Ghana, the largest e-waste site in Africa, by collecting both fixed-site and personal samples for analyzing a wide range of VOCs. A total of 54 VOCs were detected, dominated by aliphatic and aromatic compounds. Mean and median concentrations of the total target VOCs were 46 and 37 μg/m3 at the fixed sites, and 485 and 162 μg/m3 for the personal samples. Mean and median hazard ratios were 2.1 and 1.4, respectively, and cancer risks were 4.6 × 10-4 and 1.5 × 10-4. These risks were predominantly driven by naphthalene and benzene; chloroform and formaldehyde were also high in some samples. Based on the VOC composition, the major sources were industry, fuel evaporation and combustion. The concentration gradient across sites and the similarity of VOC profiles indicated that the e-waste site emissions reached neighboring communities. Our results suggest the need to protect e-waste workers from VOC exposure, and to limit emissions that can expose nearby populations.
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Affiliation(s)
- Nan Lin
- Department of Environmental Health Sciences, School of Public Health, University of Michigan, Ann Arbor, MI, USA 48109; Department of Environmental Health, School of Public Health, Shanghai Jiao Tong University, Shanghai, PR China 200025
| | - Lawrencia Kwarteng
- Department of Biological, Environmental and Occupational Health Sciences, University of Ghana, School of Public Health, P.O. Box LG13, Accra, Ghana
| | - Christopher Godwin
- Department of Environmental Health Sciences, School of Public Health, University of Michigan, Ann Arbor, MI, USA 48109
| | - Sydni Warner
- Department of Environmental Health Sciences, School of Public Health, University of Michigan, Ann Arbor, MI, USA 48109
| | - Thomas Robins
- Department of Environmental Health Sciences, School of Public Health, University of Michigan, Ann Arbor, MI, USA 48109
| | - John Arko-Mensah
- Department of Biological, Environmental and Occupational Health Sciences, University of Ghana, School of Public Health, P.O. Box LG13, Accra, Ghana
| | - Julius N Fobil
- Department of Biological, Environmental and Occupational Health Sciences, University of Ghana, School of Public Health, P.O. Box LG13, Accra, Ghana
| | - Stuart Batterman
- Department of Environmental Health Sciences, School of Public Health, University of Michigan, Ann Arbor, MI, USA 48109.
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4
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Lin N, Rosemberg MA, Li W, Meza-Wilson E, Godwin C, Batterman S. Occupational exposure and health risks of volatile organic compounds of hotel housekeepers: Field measurements of exposure and health risks. INDOOR AIR 2021; 31:26-39. [PMID: 32609907 PMCID: PMC8020495 DOI: 10.1111/ina.12709] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2020] [Revised: 06/19/2020] [Accepted: 06/24/2020] [Indexed: 05/08/2023]
Abstract
Hotel housekeepers represent a large, low-income, predominantly minority, and high-risk workforce. Little is known about their exposure to chemicals, including volatile organic compounds (VOCs). This study evaluates VOC exposures of housekeepers, sources and factors affecting VOC levels, and provides preliminary estimates of VOC-related health risks. We utilized indoor and personal sampling at two hotels, assessed ventilation, and characterized the VOC composition of cleaning agents. Personal sampling of hotel staff showed a total target VOC concentration of 57 ± 36 µg/m3 (mean ± SD), about twice that of indoor samples. VOCs of greatest health significance included chloroform and formaldehyde. Several workers had exposure to alkanes that could cause non-cancer effects. VOC levels were negatively correlated with estimated air change rates. The composition and concentrations of the tested products and air samples helped identify possible emission sources, which included building sources (for formaldehyde), disinfection by-products in the laundry room, and cleaning products. VOC levels and the derived health risks in this study were at the lower range found in the US buildings. The excess lifetime cancer risk (average of 4.1 × 10-5 ) still indicates a need to lower exposure by reducing or removing toxic constituents, especially formaldehyde, or by increasing ventilation rates.
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Affiliation(s)
- Nan Lin
- Department of Environmental Health Sciences, School of Public Health, University of Michigan, Ann Arbor, Michigan, USA 48109
| | - Marie-Anne Rosemberg
- Department of Systems, Populations and Leadership, School of Nursing, University of Michigan, Ann Arbor, Michigan, USA 48109
| | - Wei Li
- Department of Systems, Populations and Leadership, School of Nursing, University of Michigan, Ann Arbor, Michigan, USA 48109
| | - Emily Meza-Wilson
- College of Literature, Science and the Arts, University of Michigan, Ann Arbor, Michigan, USA 48109
| | - Christopher Godwin
- Department of Environmental Health Sciences, School of Public Health, University of Michigan, Ann Arbor, Michigan, USA 48109
| | - Stuart Batterman
- Department of Environmental Health Sciences, School of Public Health, University of Michigan, Ann Arbor, Michigan, USA 48109
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5
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Dikpati A, Mohammadi F, Greffard K, Quéant C, Arnaud P, Bastiat G, Rudkowska I, Bertrand N. Residual Solvents in Nanomedicine and Lipid-Based Drug Delivery Systems: a Case Study to Better Understand Processes. Pharm Res 2020; 37:149. [DOI: 10.1007/s11095-020-02877-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2020] [Accepted: 07/08/2020] [Indexed: 01/06/2023]
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6
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Review of the evidence for thresholds for DNA-Reactive and epigenetic experimental chemical carcinogens. Chem Biol Interact 2019; 301:88-111. [DOI: 10.1016/j.cbi.2018.11.011] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2018] [Revised: 11/06/2018] [Accepted: 11/22/2018] [Indexed: 01/01/2023]
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7
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Hard GC. Critical review of renal tubule karyomegaly in non-clinical safety evaluation studies and its significance for human risk assessment. Crit Rev Toxicol 2018; 48:575-595. [DOI: 10.1080/10408444.2018.1503641] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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8
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DNA extraction on bio-chip: history and preeminence over conventional and solid-phase extraction methods. Appl Microbiol Biotechnol 2017; 101:8077-8088. [PMID: 28942548 DOI: 10.1007/s00253-017-8493-0] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2017] [Revised: 05/11/2017] [Accepted: 08/30/2017] [Indexed: 12/12/2022]
Abstract
This review covers a developmental progression on early to modern taxonomy at cellular level following the advent of electron microscopy and the advancement in deoxyribonucleic acid (DNA) extraction for expatiation of biological classification at DNA level. Here, we discuss the fundamental values of conventional chemical methods of DNA extraction using liquid/liquid extraction (LLE) followed by development of solid-phase extraction (SPE) methods, as well as recent advances in microfluidics device-based system for DNA extraction on-chip. We also discuss the importance of DNA extraction as well as the advantages over conventional chemical methods, and how Lab-on-a-Chip (LOC) system plays a crucial role for the future achievements.
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9
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Chloroform induces HIF-1α-dependent VEGF expression in human keratinocytes. Mol Cell Toxicol 2013. [DOI: 10.1007/s13273-013-0042-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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10
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Sasso AF, Schlosser PM, Kedderis GL, Genter MB, Snawder JE, Li Z, Rieth S, Lipscomb JC. Application of an updated physiologically based pharmacokinetic model for chloroform to evaluate CYP2E1-mediated renal toxicity in rats and mice. Toxicol Sci 2012; 131:360-74. [PMID: 23143927 DOI: 10.1093/toxsci/kfs320] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Physiologically based pharmacokinetic (PBPK) models are tools for interpreting toxicological data and extrapolating observations across species and route of exposure. Chloroform (CHCl(3)) is a chemical for which there are PBPK models available in different species and multiple sites of toxicity. Because chloroform induces toxic effects in the liver and kidneys via production of reactive metabolites, proper characterization of metabolism in these tissues is essential for risk assessment. Although hepatic metabolism of chloroform is adequately described by these models, there is higher uncertainty for renal metabolism due to a lack of species-specific data and direct measurements of renal metabolism. Furthermore, models typically fail to account for regional differences in metabolic capacity within the kidney. Mischaracterization of renal metabolism may have a negligible effect on systemic chloroform levels, but it is anticipated to have a significant impact on the estimated site-specific production of reactive metabolites. In this article, rate parameters for chloroform metabolism in the kidney are revised for rats, mice, and humans. New in vitro data were collected in mice and humans for this purpose and are presented here. The revised PBPK model is used to interpret data of chloroform-induced kidney toxicity in rats and mice exposed via inhalation and drinking water. Benchmark dose (BMD) modeling is used to characterize the dose-response relationship of kidney toxicity markers as a function of PBPK-derived internal kidney dose. Applying the PBPK model, it was also possible to characterize the dose response for a recent data set of rats exposed via multiple routes simultaneously. Consistent BMD modeling results were observed regardless of species or route of exposure.
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Affiliation(s)
- Alan F Sasso
- National Center for Environmental Assessment, Office of Research and Development, U.S. Environmental Protection Agency, Washington, DC 20460, USA.
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11
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Kawamoto T, Pham TTP, Matsuda T, Oyama T, Tanaka M, Yu HS, Uchiyama I. Historical review on development of environmental quality standards and guideline values for air pollutants in Japan. Int J Hyg Environ Health 2011; 214:296-304. [PMID: 21680244 DOI: 10.1016/j.ijheh.2011.05.007] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2010] [Revised: 04/09/2011] [Accepted: 05/17/2011] [Indexed: 11/30/2022]
Abstract
Environmental quality standards (EQSs) have been established as desirable levels to be maintained for protection of human health and the conservation of the living environment by Basic Environment Law. EQSs in ambient air had been set for 10 substances (sulfur dioxide (SO(2)), carbon monoxide (CO), suspended particulate matter (SPM), nitrogen dioxide (NO(2)) and photochemical oxidants (Ox), benzene, tetrachloroethylene, trichloroethylene, dioxins and dichloromethane) and guideline values for 7 (acrylonitorile, vinyl chloride monomer, mercury, nickel compounds, 1,3-butadiene, chloroform and 1,2-dichloromethane) in Japan by 2009. EQSs for the classical (or traditional) air pollutants, SO(2), CO, SPM, NO(2) and Ox, were set according to the minimal requirement to protect human health, based on evidence from epidemiological studies conducted before the 1970s. In 1996, the Central Environment Council designated substances which may be hazardous air pollutants and substances requiring priority action, and adopted the concept of risk assessment to set EQSs and guideline values. A life-long risk level (virtually safe dose) of 10(-5) was used to set EQS for benzene, and guideline values for vinyl chloride monomer, nickel compounds, and 1,3-butadiene. EQSs for trichloroethylene, tetrachloroethylene and dichloromethane, and guideline values for acrylonitorile and mercury were set using uncertain factors and lowest observed adverse effect (LOAEL)/no observed adverse effect level (NOAEL). The results of animal experiments were utilized to set guideline values for chloroform and 1,2-dichloroethane. The benchmark approach and human equivalent concentration (HEC) were adopted for 1,2-dichloroethane. The history of setting EQSs and guideline values for hazardous air pollutants is one of adopting new concepts into risk assessment.
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Affiliation(s)
- Toshihiro Kawamoto
- Department of Environmental Health, University of Occupational and Environmental Health, Japan.
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12
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Take M, Yamamoto S, Ohnishi M, Matsumoto M, Nagano K, Hirota T, Fukushima S. Chloroform distribution and accumulation by combined inhalation plus oral exposure routes in rats. JOURNAL OF ENVIRONMENTAL SCIENCE AND HEALTH. PART A, TOXIC/HAZARDOUS SUBSTANCES & ENVIRONMENTAL ENGINEERING 2010; 45:1616-1624. [PMID: 20730654 DOI: 10.1080/10934529.2010.506121] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
The present investigation was undertaken to determine the distribution and accumulation of chloroform in the blood, liver, kidney and abdominal fat of rats after simultaneous exposure by two routes, inhalation and oral. To distinguish the contribution of each route, unmodified chloroform (CHCl3) was administered by inhalation and deuterated chloroform (CDCl3) was administered orally. Exposure by inhalation and oral administration resulted in CHCl3 and CDCl3 concentrations in the tissues which were significantly higher than when exposure was by either inhalation or oral administration alone. This is the first study to follow the contribution of each of two routes of chloroform exposure on chloroform distribution and accumulation in target tissues. Our results indicate that when assessing the toxicity and carcinogenicity of chloroform, exposure routes, especially the effects of exposure by multiple routes, must be taken into consideration.
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Affiliation(s)
- Makoto Take
- Japan Bioassay Research Center, Japan Industrial Safety and Health Association, Hadano, Kanagawa, Japan.
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13
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Luke NS, Sams R, DeVito MJ, Conolly RB, El-Masri HA. Development of a quantitative model incorporating key events in a hepatotoxic mode of action to predict tumor incidence. Toxicol Sci 2010; 115:253-66. [PMID: 20106946 DOI: 10.1093/toxsci/kfq021] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Biologically based dose-response (BBDR) modeling of environmental pollutants can be utilized to inform the mode of action (MOA) by which compounds elicit adverse health effects. Chemicals that produce tumors are typically labeled as either genotoxic or nongenotoxic. Though both the genotoxic and the nongenotoxic MOA may be operative as a function of dose, it is important to note that the label informs but does not define a MOA. One commonly proposed MOA for nongenotoxic carcinogens is characterized by the key events cytotoxicity and regenerative proliferation. The increased division rate associated with such proliferation can cause an increase in the probability of mutations, which may result in tumor formation. We included these steps in a generalized computational pharmacodynamic (PD) model incorporating cytotoxicity as a MOA for three carcinogens (chloroform, CHCl(3); carbon tetrachloride, CCL(4); and N,N-dimethylformamide, DMF). For each compound, the BBDR model is composed of a chemical-specific physiologically based pharmacokinetic model linked to a PD model of cytotoxicity and cellular proliferation. The rate of proliferation is then linked to a clonal growth model to predict tumor incidences. Comparisons of the BBDR simulations and parameterizations across chemicals suggested that significant variation among the models for the three chemicals arises in a few parameters expected to be chemical specific (such as metabolism and cellular injury rate constants). Optimization of model parameters to tumor data for CCL(4) and DMF resulted in similar estimates for all parameters related to cytotoxicity and tumor incidences. However, optimization of the CHCl(3) data resulted in a higher estimate for one parameter (BD) related to death of initiated cells. This implies that additional steps beyond cytotoxicity leading to induced cellular proliferation can be quantitatively different among chemicals that share cytotoxicity as a hypothesized carcinogenic MOA.
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Affiliation(s)
- Nicholas S Luke
- Department of Mathematics, North Carolina Agricultural and Technical State University, Greensboro, North Carolina 27411, USA
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14
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Take M, Ohnishi M, Nagano K, Yamamoto S, Fukushima S. Design and performance of a system for blood collection of rats under whole-body inhalation exposure. J Toxicol Sci 2009; 34:221-6. [DOI: 10.2131/jts.34.221] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Affiliation(s)
- Makoto Take
- Japan Bioassay Research Center, Japan Industrial Safety and Health Association
| | - Makoto Ohnishi
- Japan Bioassay Research Center, Japan Industrial Safety and Health Association
| | - Kasuke Nagano
- Japan Bioassay Research Center, Japan Industrial Safety and Health Association
| | - Seigo Yamamoto
- Japan Bioassay Research Center, Japan Industrial Safety and Health Association
| | - Shoji Fukushima
- Japan Bioassay Research Center, Japan Industrial Safety and Health Association
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15
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Liao KH, Tan YM, Conolly RB, Borghoff SJ, Gargas ML, Andersen ME, Clewell HJ. Bayesian estimation of pharmacokinetic and pharmacodynamic parameters in a mode-of-action-based cancer risk assessment for chloroform. RISK ANALYSIS : AN OFFICIAL PUBLICATION OF THE SOCIETY FOR RISK ANALYSIS 2007; 27:1535-1551. [PMID: 18093051 DOI: 10.1111/j.1539-6924.2007.00987.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Chloroform is a carcinogen in rodents and its carcinogenicity is secondary to events associated with cytotoxicity and regenerative cell proliferation. In this study, a physiologically based pharmacokinetic/pharmacodynamic (PBPK/PD) model that links the processes of chloroform metabolism, reparable cell damage, cell death, and regenerative cellular proliferation was developed to support a new cancer dose-response assessment for chloroform. Model parameters were estimated using Markov Chain Monte Carlo (MCMC) analysis in a two-step approach: (1) metabolism parameters for male and female mice and rats were estimated against available closed chamber gas uptake data; and (2) PD parameters for each of the four rodent groups were estimated from hepatic and renal labeling index data following inhalation exposures. Subsequently, the resulting rodent PD parameters together with literature values for human age-dependent physiological and metabolism parameters were used to scale up the rodent model to a human model. The human model was used to predict exposure conditions under which chloroform-mediated cytolethality is expected to occur in liver and kidney of adults and children. Using the human model, inhalation Reference Concentrations (RfCs) and oral Reference Doses (RfDs) were derived using an uncertainty factor of 10. Based on liver and kidney dose metrics, the respective RfCs were 0.9 and 0.09 ppm; and the respective RfDs were 0.4 and 3 mg/kg/day.
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Affiliation(s)
- Kai H Liao
- Center for Human Health Assessment, The Hamner Institutes for Health Sciences, Research Triangle Park, NC 27709, USA
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16
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Nagano K, Kano H, Arito H, Yamamoto S, Matsushima T. Enhancement of renal carcinogenicity by combined inhalation and oral exposures to chloroform in male rats. JOURNAL OF TOXICOLOGY AND ENVIRONMENTAL HEALTH. PART A 2006; 69:1827-42. [PMID: 16952903 DOI: 10.1080/15287390600630146] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Chloroform, ubiquitously present in indoor and outdoor air, drinking water, and some foodstuffs, enters the human body by inhalation, oral and dermal routes of exposure. In order to provide bioassay data for risk assessment of humans exposed to chloroform by multiple routes, effects of combined inhalation and oral exposures to chloroform on carcinogenicity and chronic toxicity in male F344 rats were examined. A group of 50 male rats was exposed by inhalation to 0 (clean air), 25, 50, or 100 ppm (v/v) of chloroform vapor-containing air for 6 h/d and 5 d/wk during a 104 w period, and each inhalation group was given chloroform-formulated drinking water (1000 ppm w/w) or vehicle water for 104 wk, ad libitum. Renal-cell adenomas and carcinomas and atypical renal-tubule hyperplasias were increased in the combined inhalation and oral exposure groups, but not in the oral- or inhalation-alone groups. Incidences of cytoplasmic basophilia and dilated tubular lumens in the kidney, as well as incidence of positive urinary glucose, were markedly increased by the combined exposures, compared with those after single-route exposures. It was concluded that combined inhalation and oral exposures markedly enhanced carcinogenicity and chronic toxicity in the proximal tubule of male rat kidneys, suggesting that carcinogenic and toxic effects of the combined exposures on the kidneys were greater than the ones that would be expected under an assumption that the two effects of single route exposures through inhalation and drinking were additive.
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Affiliation(s)
- Kasuke Nagano
- Japan Bioassay Research Center, Japan Industrial Safety and Health Association, Kanagawa, Japan.
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17
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Lambert IB, Singer TM, Boucher SE, Douglas GR. Detailed review of transgenic rodent mutation assays. Mutat Res 2005; 590:1-280. [PMID: 16081315 DOI: 10.1016/j.mrrev.2005.04.002] [Citation(s) in RCA: 252] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2005] [Revised: 04/04/2005] [Accepted: 04/12/2005] [Indexed: 11/17/2022]
Abstract
Induced chromosomal and gene mutations play a role in carcinogenesis and may be involved in the production of birth defects and other disease conditions. While it is widely accepted that in vivo mutation assays are more relevant to the human condition than are in vitro assays, our ability to evaluate mutagenesis in vivo in a broad range of tissues has historically been quite limited. The development of transgenic rodent (TGR) mutation models has given us the ability to detect, quantify, and sequence mutations in a range of somatic and germ cells. This document provides a comprehensive review of the TGR mutation assay literature and assesses the potential use of these assays in a regulatory context. The information is arranged as follows. (1) TGR mutagenicity models and their use for the analysis of gene and chromosomal mutation are fully described. (2) The principles underlying current OECD tests for the assessment of genotoxicity in vitro and in vivo, and also nontransgenic assays available for assessment of gene mutation, are described. (3) All available information pertaining to the conduct of TGR assays and important parameters of assay performance have been tabulated and analyzed. (4) The performance of TGR assays, both in isolation and as part of a battery of in vitro and in vivo short-term genotoxicity tests, in predicting carcinogenicity is described. (5) Recommendations are made regarding the experimental parameters for TGR assays, and the use of TGR assays in a regulatory context.
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Affiliation(s)
- Iain B Lambert
- Mutagenesis Section, Environmental Health Sciences Bureau, Healthy Environments and Consumer Safety Branch, 0803A, Health Canada, Ottawa, Ont., Canada K1A 0L2.
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Kasai T, Nishizawa T, Arito H, Nagano K, Yamamoto S, Matsushima T, Kawamoto T. Acute and Subchronic Inhalation Toxicity of Chloroform in Rats and Mice. J Occup Health 2002. [DOI: 10.1539/joh.44.193] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Affiliation(s)
- Tatsuya Kasai
- Japan Bioassay Research CenterJapan Industrial Safety and Health Association
| | - Tomoshi Nishizawa
- Japan Bioassay Research CenterJapan Industrial Safety and Health Association
| | - Heihachiro Arito
- Japan Bioassay Research CenterJapan Industrial Safety and Health Association
| | - Kasuke Nagano
- Japan Bioassay Research CenterJapan Industrial Safety and Health Association
| | - Seigo Yamamoto
- Japan Bioassay Research CenterJapan Industrial Safety and Health Association
| | - Taijiro Matsushima
- Japan Bioassay Research CenterJapan Industrial Safety and Health Association
| | - Toshihiro Kawamoto
- University of Occupational and Environmental Health, School of MedicineDepartment of Environmental HealthJapan
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