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Vincent MJ, Fitch S, Bylsma L, Thompson C, Rogers S, Britt J, Wikoff D. Assessment of associations between inhaled formaldehyde and lymphohematopoietic cancer through the integration of epidemiological and toxicological evidence with biological plausibility. Toxicol Sci 2024; 199:172-193. [PMID: 38547404 PMCID: PMC11131035 DOI: 10.1093/toxsci/kfae039] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/29/2024] Open
Abstract
Formaldehyde is recognized as carcinogenic for the portal of entry sites, though conclusions are mixed regarding lymphohematopoietic (LHP) cancers. This systematic review assesses the likelihood of a causal relationship between formaldehyde and LHP cancers by integrating components recommended by NASEM. Four experimental rodent bioassays and 16 observational studies in humans were included following the implementation of the a priori protocol. All studies were assessed for risk of bias (RoB), and meta-analyses were conducted on epidemiological studies, followed by a structured assessment of causation based on GRADE and Bradford Hill. RoB analysis identified systemic limitations precluding confidence in the epidemiological evidence due to inadequate characterization of formaldehyde exposure and a failure to adequately adjust for confounders or effect modifiers, thus suggesting that effect estimates are likely to be impacted by systemic bias. Mixed findings were reported in individual studies; meta-analyses did not identify significant associations between formaldehyde inhalation (when measured as ever/never exposure) and LHP outcomes, with meta-SMRs ranging from 0.50 to 1.51, depending on LHP subtype. No associations with LHP-related lesions were reported in reliable animal bioassays. No biologically plausible explanation linking the inhalation of FA and LHP was identified, supported primarily by the lack of systemic distribution and in vivo genotoxicity. In conclusion, the inconsistent associations reported in a subset of the evidence were not considered causal when integrated with the totality of the epidemiological evidence, toxicological data, and considerations of biological plausibility. The impact of systemic biases identified herein could be quantitatively assessed to better inform causality and use in risk assessment.
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Affiliation(s)
| | - Seneca Fitch
- ToxStrategies, LLC, Asheville, North Carolina 28801, United States
| | - Lauren Bylsma
- EpidStrategies, a Division of ToxStrategies, LLC, Katy, Texas 77494, United States
| | - Chad Thompson
- ToxStrategies, LLC, Katy, Texas 77494, United States
| | - Sarah Rogers
- ToxStrategies, LLC, Asheville, North Carolina 28801, United States
| | - Janice Britt
- ToxStrategies, LLC, Asheville, North Carolina 28801, United States
| | - Daniele Wikoff
- ToxStrategies, LLC, Asheville, North Carolina 28801, United States
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2
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Khoshakhlagh AH, Mohammadzadeh M, Manafi SS, Yousefian F, Gruszecka-Kosowska A. Inhalational exposure to formaldehyde, carcinogenic, and non-carcinogenic risk assessment: A systematic review. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2023:121854. [PMID: 37236589 DOI: 10.1016/j.envpol.2023.121854] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/16/2023] [Revised: 05/16/2023] [Accepted: 05/18/2023] [Indexed: 05/28/2023]
Abstract
Formaldehyde is one of the most widely used substances in a variety of industries, although it was classified as a human carcinogen by the International Agency for Research on Cancer (IARC). The present systematic review was conducted to retrieve studies related to occupational exposure to formaldehyde until November 2, 2022. Aims of the study were to identify workplaces exposed to formaldehyde, to investigate the formaldehyde concentrations in various occupations and to evaluate carcinogenic and non-carcinogenic risks caused by respiratory exposure to this chemical among workers. A systematic search was done in Scopus, PubMed and Web of Science databases to find the studies done in this field. In this review, studies that did not meet the criteria specified by Population, Exposure, Comparator, and Outcomes (PECO) approach were excluded. In addition, the inclusion of studies dealing with the biological monitoring of FA in the body and review studies, conference articles, books, and letters to the editors were avoided. The quality of the selected studies was also evaluated using the Joanna Briggs Institute (JBI) checklist for analytic-cross-sectional studies. Finally, 828 studies were found, and after the investigations, 35 articles were included in this study. The results revealed that the highest formaldehyde concentrations were observed in waterpipe cafes (1,620,000 μg/m3) and anatomy and pathology laboratories (4237.5 μg/m3). Carcinogenic and non-carcinogenic risk indicated the potential health effects for employees due to respiratory exposure as acceptable levels of CR = 1.00 × 10-4 and HQ = 1, respectively were reported to be exceeded in more than 71% and 28.57% of the investigated studies. Therefore, according to the confirmation of formaldehyde's adverse health effects, it is necessary to adopt targeted strategies to reduce or eliminate exposure to this compound from the occupational usage.
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Affiliation(s)
- Amir Hossein Khoshakhlagh
- Department of Occupational Health Engineering, School of Health, Kashan University of Medical Sciences, Kashan, Iran
| | - Mahdiyeh Mohammadzadeh
- Social Determinants of Health (SDH) Research Center, Department of Environment Health, Kashan University of Medical Sciences, Kashan, Iran.
| | - Seyede Somayeh Manafi
- Head of Environmental and Urban Health Studies, Tehran Urban Research and Planning Center Municipality of Tehran, Tehran, Iran
| | - Fatemeh Yousefian
- Department of Environmental Health Engineering, Faculty of Health, Kashan University of Medical Sciences, Kashan, Iran
| | - Agnieszka Gruszecka-Kosowska
- AGH University of Science and Technology; Faculty of Geology, Geophysics, and Environmental Protection; Department of Environmental Protection; Al. Mickiewicza 30, 30-059 Krakow, Poland
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3
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La Torre G, Vitello T, Cocchiara RA, Della Rocca C. Relationship between formaldehyde exposure, respiratory irritant effects and cancers: a review of reviews. Public Health 2023; 218:186-196. [PMID: 37060739 DOI: 10.1016/j.puhe.2023.03.009] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2022] [Revised: 02/20/2023] [Accepted: 03/10/2023] [Indexed: 04/17/2023]
Abstract
OBJECTIVES Formaldehyde is an organic compound used in the production of resins, paper, wood plywood, solvents and cleaning products. Formaldehyde is also present when tobacco is smoked. Formaldehyde has been defined as an irritant and is classified as a human carcinogen by the International Agency for Research on Cancer. The purpose of this study was to demonstrate the following two distinct correlations: (1) the association between formaldehyde exposure and development of irritant diseases affecting the respiratory tract, mainly asthma; and (2) the association between formaldehyde exposure and development of neoplastic diseases. STUDY DESIGN This was an umbrella review. METHODS A search was conducted in the three main electronic databases of scientific literature: PubMed, Scopus and Web of Science. The search included systematic reviews and meta-analyses published in the previous 10 years. Initially, titles and abstracts of retrieved articles were evaluated, then full-text assessments of selected articles took place. Data extraction and quality assessment were performed according to Assessing the Methodological Quality of Systematic Reviews (AMSTAR) score. RESULTS A total of 630 articles were initially collected. Nine articles concerning the association between formaldehyde exposure and asthma were included in the present review, and the majority of these reported good association. In addition, 27 articles investigating the association between formaldehyde exposure and neoplastic diseases were included in the review. These studies showed that nasopharyngeal cancer and leukaemia were the most represented neoplastic diseases; however, only a weak association was reported between formaldehyde exposure and cancer. CONCLUSIONS Although the studies included in this review did not show a strong association between exposure to formaldehyde and irritant or neoplastic diseases, the World Health Organisation recommends that levels of formaldehyde do not exceed the threshold value of 0.1 mg/m3 (0.08 ppm) for a period of 30 min. It is recommended that preventive measures, such as ventilation in workplaces with high exposure to formaldehyde and environmental monitoring of formaldehyde concentrations, are implemented.
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Affiliation(s)
- G La Torre
- Department of Public Health and Infectious Diseases, Sapienza University of Rome, Rome, Italy.
| | - T Vitello
- Department of Public Health and Infectious Diseases, Sapienza University of Rome, Rome, Italy
| | - R A Cocchiara
- Department of Public Health and Infectious Diseases, Sapienza University of Rome, Rome, Italy
| | - C Della Rocca
- Department of Medico-Surgical Sciences and Biotechnologies, Sapienza University of Rome, Rome, Italy
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4
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Lynch HN, Mundt KA, Pallapies D, Ricci PF. Lost in the woods: Finding our way back to the scientific method in systematic review. GLOBAL EPIDEMIOLOGY 2022; 4:100093. [PMID: 37637027 PMCID: PMC10445984 DOI: 10.1016/j.gloepi.2022.100093] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2022] [Revised: 10/20/2022] [Accepted: 11/01/2022] [Indexed: 11/11/2022] Open
Abstract
Systematic review has become the preferred approach to addressing causality and informing regulatory and other decision-making processes, including chemical risk assessments. While advocates of systematic reviews acknowledge that they hold great potential for increasing objectivity and transparency in assessments of chemicals and human health risks, standardizing and harmonizing systematic review methods have been challenging. This review provides a brief summary of the development of systematic review methods and some of the frameworks currently in use in the US and Europe. We also provide an in-depth evaluation and comparison of two "competing" US EPA systematic review frameworks, informed by the constructively critical recommendations from the US National Academies of Science, Engineering and Medicine. We conclude with suggestions for moving forward to harmonize systematic review methods, as we believe that further criticism of individual available frameworks likely will be unproductive. Specifically, we issue a call to action for an international collaboration to work toward a blueprint that embraces the most scientifically critical elements common to most systematic review frameworks, while necessarily accommodating adaptations for specific purposes. Despite the array of available systematic review methods, it is clear that there is a shared goal and desire to promote objective assessment and synthesis of scientific evidence informing globally important issues regarding disease causality and human health risk evaluation.
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Affiliation(s)
| | | | - Dirk Pallapies
- The Institute for Prevention and Occupational Medicine of the German Social Accident Insurance, Bochum, Germany
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5
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Agathokleous E, Calabrese EJ. Formaldehyde: Another hormesis-inducing chemical. ENVIRONMENTAL RESEARCH 2021; 199:111395. [PMID: 34048749 DOI: 10.1016/j.envres.2021.111395] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2021] [Revised: 05/21/2021] [Accepted: 05/22/2021] [Indexed: 06/12/2023]
Abstract
Formaldehyde (FA) is a naturally-occurring compound, produced endogenously in diverse living organisms. It also occurs widely in the environment due to anthropogenic (e.g. used as a chemical intermediate) and natural sources (e.g. a component of the volatile organic compounds blends emitted by plants). While FA is considered a potential carcinogen, living organisms have the ability to cope with FA, and some minimum endogenous levels of FA may be required for health. Recently, genetic engineering approaches transferring biological information from one organism to another led to increased assimilation of and conferred genetic-based tolerance to FA in plants-microorganisms systems. Here, we propose that FA commonly induces hormesis, a hypothesis that we confirm by collating evidence from various published studies with animals, plants, and microorganisms. The stimulation by low doses below the no-observed-adverse-effect-level (NOAEL) was modest in magnitude, in agreement with the general hormesis literature. In plants, among the endpoints showing hormesis were growth, lipid peroxidation, and photosynthetic pigments. In various animal cells, hormesis was observed in cell proliferation and viability, responses that were related to mechanisms, such as activation of phosphorylated ERK (extra-cellular signaling-regulated kinase) expression, acceleration of the process of cell division, and enhancement of the Warburg effect (i.e. use of glycolysis by tumor cells to produce energy for rapid growth). Hormetic in vitro responses were reported in several cancerous/tumorous cell lines, suggesting that FA has the potential to influence tumor promotion within a specific concentration range and biological context. These observations suggest that FA commonly acts in an hormetic manner with implications for study designs across a broad range of biological models and in the assessment of environmental and human risks associated with FA exposures.
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Affiliation(s)
- Evgenios Agathokleous
- Key Laboratory of Agrometeorology of Jiangsu Province, Department of Ecology, School of Applied Meteorology, Nanjing University of Information Science & Technology (NUIST), Nanjing, 210044, PR China.
| | - Edward J Calabrese
- Department of Environmental Health Sciences, Morrill I, N344, University of Massachusetts, Amherst, MA, 01003, USA
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6
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Thompson CM, Gentry R, Fitch S, Lu K, Clewell HJ. An updated mode of action and human relevance framework evaluation for Formaldehyde-Related nasal tumors. Crit Rev Toxicol 2021; 50:919-952. [PMID: 33599198 DOI: 10.1080/10408444.2020.1854679] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Formaldehyde is a reactive aldehyde naturally present in all plant and animal tissues and a critical component of the one-carbon metabolism pathway. It is also a high production volume chemical used in the manufacture of numerous products. Formaldehyde is also one of the most well-studied chemicals with respect to environmental fate, biology, and toxicology-including carcinogenic potential, and mode of action (MOA). In 2006, a published MOA for formaldehyde-induced nasal tumors in rats concluded that nasal tumors were most likely driven by cytotoxicity and regenerative cell proliferation, with possible contributions from direct genotoxicity. In the past 15 years, new research has better informed the MOA with the publication of in vivo genotoxicity assays, toxicogenomic analyses, and development of ultra-sensitive methods to measure endogenous and exogenous formaldehyde-induced DNA adducts. Herein, we review and update the MOA for nasal tumors, with particular emphasis on the numerous studies published since 2006. These new studies further underscore the involvement of cytotoxicity and regenerative cell proliferation, and further inform the genotoxic potential of inhaled formaldehyde. The data lend additional support for the use of mechanistic data for the derivation of toxicity criteria and/or scientifically supported approaches for low-dose extrapolation for the risk assessment of formaldehyde.
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Affiliation(s)
| | | | | | - Kun Lu
- Department of Environmental Sciences and Engineering, University of North Carolina at Chapel Hill, NC, USA
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7
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Gentry R, Thompson CM, Franzen A, Salley J, Albertini R, Lu K, Greene T. Using mechanistic information to support evidence integration and synthesis: a case study with inhaled formaldehyde and leukemia. Crit Rev Toxicol 2021; 50:885-918. [PMID: 33538218 DOI: 10.1080/10408444.2020.1854678] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Formaldehyde is one of the most comprehensively studied chemicals, with over 30 years of research focused on understanding the development of cancer following inhalation. The causal conclusions regarding the potential for leukemia are largely based on the epidemiological literature, with little consideration of cancer bioassays, dosimetry studies, and mechanistic research, which challenge the biological plausibility of the disease. Recent reanalyzes of the epidemiological literature have also raised significant questions related to the purported associations between formaldehyde and leukemia. Because of this, considerable scientific debate and uncertainty remain on whether there is a causal association between formaldehyde inhalation exposure and leukemia. Further complexity in evaluating this association is related to the endogenous production of formaldehyde. Multiple modes of action (MOA) have been postulated for the development of leukemia following formaldehyde inhalation that includes unsupported hypotheses of direct or indirect toxicity to the target cell population. Herein, the available evidence relevant to evaluating the postulated MOAs for leukemia following formaldehyde inhalation exposure is organized in the IPCS MOA Framework. The integration of all the available evidence clearly highlights the limited amount of data that support any of the postulated MOAs and demonstrates a significant amount of research supporting the null hypothesis that there is no causal association between formaldehyde inhalation exposure and leukemia. These analyses result in a lack of confidence in any of the postulated MOAs, increasing confidence in the conclusion that there is a lack of biological plausibility for a causal association between formaldehyde inhalation exposure and leukemia.
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Affiliation(s)
| | | | | | | | - Richard Albertini
- Independent Consultant, Emeritus Professor, University of Vermont, Burlington, Vermont, USA
| | - Kun Lu
- Department of Environmental Sciences and Engineering, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
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8
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Goodman JE, Mayfield DB, Becker RA, Hartigan SB, Erraguntla NK. Recommendations for further revisions to improve the International Agency for Research on Cancer (IARC) Monograph program. Regul Toxicol Pharmacol 2020; 113:104639. [PMID: 32147291 DOI: 10.1016/j.yrtph.2020.104639] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2019] [Revised: 02/03/2020] [Accepted: 02/29/2020] [Indexed: 10/24/2022]
Abstract
In 2019, the International Agency for Research on Cancer (IARC) "Preamble to the IARC Monographs" expanded guidance regarding the scientific approaches that should be employed in its monographs. These amendments to the monograph development process are an improvement but still fall short in several areas. While the revised Preamble lays out broad methods and approaches to evaluate scientific evidence, there is a lack of specificity with regard to how IARC Working Groups will conduct consistent evaluations in a standardized, objective, and transparent manner; document systematic review and evidence integration actions, and substantiate how these actions and decisions inform the ultimate classifications. Furthermore, no guidance is provided to ensure Working Groups consistently incorporate mechanistic evidence in a robust manner using a defined approach in the context of 21st century knowledge of modes of action. Nor are the conclusions of the working groups subjected to outside, independent scientific peer review. Continued improvements and modernization of the procedures for evaluating, presenting, and communicating study quality, and in the methods used to conduct and peer-review evidence-based decision making will benefit the Working Group members, the IARC Monographs Programme overall, and the international regulatory community and public who rely upon the monographs.
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Affiliation(s)
- Julie E Goodman
- Gradient, One Beacon Street, 17th Floor, Boston, MA, 02108, USA.
| | - David B Mayfield
- Gradient, 600 Stewart Street, Suite 1900, Seattle, WA, 98101, USA.
| | - Richard A Becker
- American Chemistry Council, 700 2nd Street NE, Washington, DC, 20002, USA.
| | - Suzanne B Hartigan
- American Chemistry Council, 700 2nd Street NE, Washington, DC, 20002, USA.
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9
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Hanson ML, Solomon KR, Van Der Kraak GJ, Brian RA. Effects of atrazine on fish, amphibians, and reptiles: update of the analysis based on quantitative weight of evidence. Crit Rev Toxicol 2020; 49:670-709. [DOI: 10.1080/10408444.2019.1701985] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Affiliation(s)
- Mark L. Hanson
- Department of Environment and Geography, University of Manitoba, Winnipeg, MB, Canada
| | - Keith R. Solomon
- School of Environmental Sciences, University of Guelph, Guelph, ON, Canada
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10
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Allegra A, Spatari G, Mattioli S, Curti S, Innao V, Ettari R, Allegra AG, Giorgianni C, Gangemi S, Musolino C. Formaldehyde Exposure and Acute Myeloid Leukemia: A Review of the Literature. MEDICINA (KAUNAS, LITHUANIA) 2019; 55:E638. [PMID: 31557975 PMCID: PMC6843642 DOI: 10.3390/medicina55100638] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/20/2019] [Revised: 09/06/2019] [Accepted: 09/20/2019] [Indexed: 01/14/2023]
Abstract
Background and objective: The aim of the present study was to evaluate associations between cumulative and peak formaldehyde exposure and occurrence of acute myeloid leukemia. Material and Methods: A comprehensive search was performed using the PubMed and Embase databases. We included studies presenting information about the role of formaldehyde in leukemic occurrence and mortality risk. Then, full texts of the selected references were assessed, and references of included studies were checked to identify additional articles. Result: The information was then summarized and organized in the present review. A total of 81 articles were obtained from the search. Conclusion: Findings from the review of the literature do not support the hypothesis that formaldehyde is a cause of acute myeloid leukemia.
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Affiliation(s)
- Alessandro Allegra
- Division of Hematology, Department of Human Pathology in Adulthood and Childhood, University of Messina, 98122 Messina, Italy.
| | - Giovanna Spatari
- Department of Environmental Science, Safety, Territory, Food and Health, University of Messina, 98122 Messina, Italy.
| | - Stefano Mattioli
- Department of Medical and Surgical Sciences (DIMEC), University of Bologna, 40126 Bologna, Italy.
| | - Stefania Curti
- Department of Medical and Surgical Sciences (DIMEC), University of Bologna, 40126 Bologna, Italy.
| | - Vanessa Innao
- Division of Hematology, Department of Human Pathology in Adulthood and Childhood, University of Messina, 98122 Messina, Italy.
| | - Roberta Ettari
- Department of Chemical, Biological, Pharmaceutical and Environmental Sciences, University of Messina, 98122 Messina, Italy.
| | - Andrea Gaetano Allegra
- Division of Hematology, Department of Human Pathology in Adulthood and Childhood, University of Messina, 98122 Messina, Italy.
| | - Concetto Giorgianni
- Department of Environmental Science, Safety, Territory, Food and Health, University of Messina, 98122 Messina, Italy.
| | - Sebastiano Gangemi
- School and Division of Allergy and Clinical Immunology, Department of Clinical and Experimental Medicine, University Hospital "G. Martino", Via Consolare Valeria SNC, 98125 Messina, Italy.
| | - Caterina Musolino
- Division of Hematology, Department of Human Pathology in Adulthood and Childhood, University of Messina, 98122 Messina, Italy.
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11
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Min YS, Choi H, Yoo CI, Ahn YS. Cancer mortality in Korean workers occupationally exposed to methanol: a cohort study. Int Arch Occup Environ Health 2018; 92:551-557. [PMID: 30535884 DOI: 10.1007/s00420-018-1389-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2018] [Accepted: 11/24/2018] [Indexed: 11/24/2022]
Abstract
PURPOSE Recently, the international agency for research on cancer recommended that methanol should be recognized as a medium-priority, human cancer risk. Therefore, we performed an epidemiological study to evaluate the relationship between methanol exposure and the cancer mortality of Korean workers occupationally exposed to methanol. METHODS The study cohort was composed of methanol-exposed 25,218 male workers, data on whom were available from the Korea Occupational Safety and Health Agency; all participants underwent methanol-associated medical check-ups at least once between January 2000 and December 2004. The durations of methanol exposure were categorized as < 10, 10-20, and ≥ 20 years. Workplace methanol exposure levels for each worker were divided into three grades. We compared their standardized cancer mortality rates (SMRs) to those of the general population. Intra-cohort hazard ratios were estimated using a Cox's proportional hazards model. RESULTS We found no positive association between methanol exposure and cancer mortality. In terms of all cancer mortality, methanol-exposed workers exhibited significantly lower SMRs than the general population. In terms of other cancer mortality, no significant difference or trend was evident as a function of duration of methanol exposure. CONCLUSIONS Although we found no significant correlation between methanol exposure and cancer mortality, we believe the work is meaningful; this is the first, large-scale, human epidemiological study. The carcinogenic potential of methanol remains an open question, and studies with longer-term follow-up periods are needed.
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Affiliation(s)
- Young-Sun Min
- Department of Occupational and Environmental Medicine, Dongguk University Gyeongju Hospital, Gyeongju, South Korea
| | - Hongsuk Choi
- Department of Occupational and Environmental Medicine, Dongguk University Gyeongju Hospital, Gyeongju, South Korea
| | - Cheol-In Yoo
- Department of Occupational and Environmental Medicine, Ulsan University Hospital, University of Ulsan College of Medicine, Ulsan, South Korea
| | - Yeon-Soon Ahn
- Department of Preventive Medicine, Institute Occupational and Environmental Medicine, Yonsei University Wonju College of Medicine, Wonju, South Korea.
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12
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Li LJ, Chai Y, Guo XJ, Chu SL, Zhang LS. Effects of endoplasmic reticulum stress on autophagy and apoptosis of human leukemia cells via inhibition of the PI3K/AKT/mTOR signaling pathway. Mol Med Rep 2018; 17:7886-7892. [PMID: 29620275 DOI: 10.3892/mmr.2018.8840] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2016] [Accepted: 12/18/2017] [Indexed: 11/05/2022] Open
Abstract
The present study aimed to explore the regulatory effects of endoplasmic reticulum stress (ERS) on the phosphoinositide 3‑kinase (PI3K)/AKT serine/threonine kinase 1 (AKT)/mammalian target of rapamycin (mTOR) signaling pathway, and its subsequent effects on autophagy and apoptosis of human leukemia cells. Human leukemia cells were cultured and treated with various concentrations of tunicamycin for 0, 24, 48, 72 and 90 h. Subsequently, human leukemia cells were assigned into the ER activation group, which was treated with 100 ng/ml tunicamycin, the ER activation + TO901317 (PI3K inhibitor) group, and the control group. An MTT assay was conducted to detect cell proliferation. In addition, a monodansylcadaverine (MDC) assay was used to detect the formation of autophagosomes and Annexin V‑fluorescein isothiocyanate/propidium iodide double staining was used to examine cell apoptosis. Western blotting was performed to detect the expression levels of 78‑kDa glucose‑regulated protein (GRP78), phosphorylated (p)‑protein kinase R‑like endoplasmic reticulum kinase (PERK), p‑α subunit of eukaryotic initiation factor 2 (eIF2α), microtubule‑associated protein 1A/1B‑light chain 3 (LC3), caspase‑3, CCAAT‑enhancer‑binding protein homologous protein (CHOP), PI3K, AKT and mTOR. Treatment with 100 ng/ml tunicamycin for 72 h was considered the optimal condition for further experiments. Compared with in cells prior to treatment, human leukemia cells treated with tunicamycin exhibited increased expression of p‑PERK, p‑eIF2α and GRP78 after 72 h (P<0.05). In addition, the expression levels of mTOR, AKT and PI3K were decreased in the ER activation group compared with in the control and ER activation + TO901317 groups (P<0.05). Compared with in the control group, cell proliferation was inhibited and MDC fluorescence intensity was increased in the ER activation group (P<0.05). Furthermore, compared with in the control and ER activation + TO901317 groups, western blotting indicated that the expression levels of LC3‑II were increased in the ER activation group (P<0.05). The apoptotic rate was also higher in the ER activation group compared with in the control group (P<0.05), and caspase‑3 and CHOP expression was elevated in the ER activation group (P<0.05). These findings indicated that ERS may induce autophagy and apoptosis of human leukemia cells via inhibiting the PI3K/AKT/mTOR signaling pathway.
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Affiliation(s)
- Li-Juan Li
- Department of Hematology, Lanzhou University Second Hospital, Lanzhou, Gansu 730000, P.R. China
| | - Ye Chai
- Department of Hematology, Lanzhou University Second Hospital, Lanzhou, Gansu 730000, P.R. China
| | - Xiao-Jia Guo
- Department of Hematology, Lanzhou University Second Hospital, Lanzhou, Gansu 730000, P.R. China
| | - Song-Lin Chu
- Department of Hematology, Lanzhou University Second Hospital, Lanzhou, Gansu 730000, P.R. China
| | - Lian-Sheng Zhang
- Department of Hematology, Lanzhou University Second Hospital, Lanzhou, Gansu 730000, P.R. China
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13
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Mundt KA, Gentry PR, Dell LD, Rodricks JV, Boffetta P. Six years after the NRC review of EPA's Draft IRIS Toxicological Review of Formaldehyde: Regulatory implications of new science in evaluating formaldehyde leukemogenicity. Regul Toxicol Pharmacol 2017; 92:472-490. [PMID: 29158043 DOI: 10.1016/j.yrtph.2017.11.006] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2017] [Revised: 10/27/2017] [Accepted: 11/15/2017] [Indexed: 11/28/2022]
Abstract
Shortly after the International Agency for Research on Cancer (IARC) determined that formaldehyde causes leukemia, the United States Environmental Protection Agency (EPA) released its Draft IRIS Toxicological Review of Formaldehyde ("Draft IRIS Assessment"), also concluding that formaldehyde causes leukemia. Peer review of the Draft IRIS Assessment by a National Academy of Science committee noted that "causal determinations are not supported by the narrative provided in the draft" (NRC 2011). They offered recommendations for improving the Draft IRIS assessment and identified several important research gaps. Over the six years since the NRC peer review, significant new science has been published. We identify and summarize key recommendations made by NRC and map them to this new science, including extended analysis of epidemiological studies, updates of earlier occupational cohort studies, toxicological experiments using a sensitive mouse strain, mechanistic studies examining the role of exogenous versus endogenous formaldehyde in bone marrow, and several critical reviews. With few exceptions, new findings are consistently negative, and integration of all available evidence challenges the earlier conclusions that formaldehyde causes leukemia. Given formaldehyde's commercial importance, environmental ubiquity and endogenous production, accurate hazard classification and risk evaluation of whether exposure to formaldehyde from occupational, residential and consumer products causes leukemia are critical.
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Affiliation(s)
- Kenneth A Mundt
- Environment and Health, Ramboll Environ, Amherst MA, United States.
| | - P Robinan Gentry
- Environment and Health, Ramboll Environ, Amherst MA, United States
| | - Linda D Dell
- Environment and Health, Ramboll Environ, Amherst MA, United States
| | | | - Paolo Boffetta
- Icahn School of Medicine at Mount Sinai, New York, NY, USA
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Nielsen GD, Larsen ST, Wolkoff P. Re-evaluation of the WHO (2010) formaldehyde indoor air quality guideline for cancer risk assessment. Arch Toxicol 2017; 91:35-61. [PMID: 27209488 PMCID: PMC5225186 DOI: 10.1007/s00204-016-1733-8] [Citation(s) in RCA: 112] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2016] [Accepted: 04/27/2016] [Indexed: 11/11/2022]
Abstract
In 2010, the World Health Organization (WHO) established an indoor air quality guideline for short- and long-term exposures to formaldehyde (FA) of 0.1 mg/m3 (0.08 ppm) for all 30-min periods at lifelong exposure. This guideline was supported by studies from 2010 to 2013. Since 2013, new key studies have been published and key cancer cohorts have been updated, which we have evaluated and compared with the WHO guideline. FA is genotoxic, causing DNA adduct formation, and has a clastogenic effect; exposure-response relationships were nonlinear. Relevant genetic polymorphisms were not identified. Normal indoor air FA concentrations do not pass beyond the respiratory epithelium, and therefore FA's direct effects are limited to portal-of-entry effects. However, systemic effects have been observed in rats and mice, which may be due to secondary effects as airway inflammation and (sensory) irritation of eyes and the upper airways, which inter alia decreases respiratory ventilation. Both secondary effects are prevented at the guideline level. Nasopharyngeal cancer and leukaemia were observed inconsistently among studies; new updates of the US National Cancer Institute (NCI) cohort confirmed that the relative risk was not increased with mean FA exposures below 1 ppm and peak exposures below 4 ppm. Hodgkin's lymphoma, not observed in the other studies reviewed and not considered FA dependent, was increased in the NCI cohort at a mean concentration ≥0.6 mg/m3 and at peak exposures ≥2.5 mg/m3; both levels are above the WHO guideline. Overall, the credibility of the WHO guideline has not been challenged by new studies.
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Affiliation(s)
- Gunnar Damgård Nielsen
- National Research Centre for the Working Environment, Lersø Parkallé 105, 2100, Copenhagen, Denmark.
| | - Søren Thor Larsen
- National Research Centre for the Working Environment, Lersø Parkallé 105, 2100, Copenhagen, Denmark
| | - Peder Wolkoff
- National Research Centre for the Working Environment, Lersø Parkallé 105, 2100, Copenhagen, Denmark
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15
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Haussmann HJ, Fariss MW. Comprehensive review of epidemiological and animal studies on the potential carcinogenic effects of nicotine per se. Crit Rev Toxicol 2016; 46:701-34. [PMID: 27278157 PMCID: PMC5020336 DOI: 10.1080/10408444.2016.1182116] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2015] [Revised: 03/14/2016] [Accepted: 04/20/2016] [Indexed: 12/31/2022]
Abstract
The effects of long-term use of nicotine per se on cancer risk, in the absence of tobacco extract or smoke, are not clearly understood. This review evaluates the strength of published scientific evidence, in both epidemiological and animal studies, for the potential carcinogenic effects of nicotine per se; that is to act as a complete carcinogen or as a modulator of carcinogenesis. For human studies, there appears to be inadequate evidence for an association between nicotine exposure and the presence of or lack of a carcinogenic effect due to the limited information available. In animal studies, limited evidence suggests an association between long-term nicotine exposure and a lack of a complete carcinogenic effect. Conclusive studies using current bioassay guidelines, however, are missing. In studies using chemical/physical carcinogens or transgenic models, there appears to be inadequate evidence for an association between nicotine exposure and the presence of or lack of a modulating (stimulating) effect on carcinogenesis. This is primarily due to the large number of conflicting studies. In contrast, a majority of studies provides sufficient evidence for an association between nicotine exposure and enhanced carcinogenesis of cancer cells inoculated in mice. This modulating effect was especially prominent in immunocompromized mice. Overall, taking the human and animal studies into consideration, there appears to be inadequate evidence to conclude that nicotine per se does or does not cause or modulate carcinogenesis in humans. This conclusion is in agreement with the recent US Surgeon General's 2014 report on the health consequences of nicotine exposure.
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Rhomberg LR. Contrasting directions and directives on hazard identification for formaldehyde carcinogenicity. Regul Toxicol Pharmacol 2015; 73:829-33. [PMID: 26493002 DOI: 10.1016/j.yrtph.2015.10.012] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2015] [Accepted: 10/15/2015] [Indexed: 01/07/2023]
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17
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Hasselbalch HC. Smoking as a contributing factor for development of polycythemia vera and related neoplasms. Leuk Res 2015; 39:S0145-2126(15)30373-8. [PMID: 26463040 DOI: 10.1016/j.leukres.2015.09.002] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2015] [Revised: 08/29/2015] [Accepted: 09/04/2015] [Indexed: 12/17/2022]
Abstract
Smoking may be associated with accelerated erythropoiesis, leukocytosis and thrombocytosis, which are also hallmarks in patients with polycythemia vera, essential thrombocythemia and early stages of myelofibrosis (MPNs). The JAK-STAT and NF-κB signaling pathways are activated in both smokers and in patients with MPNs. Additionally, both share elevated levels of several proinflammatory cytokines, in vivo activation of leukocytes and platelets, endothelial dysfunction and increased systemic oxidative stress. Based upon experimental, epidemiological and clinical data it is herein argued and discussed, if smoking may be involved in MPN pathogenesis, considering most recent studies and reviews which are supportive of the concept that chronic inflammation with NF-κB activation and oxidative stress may have a major role - both as triggers but also as the driving force for clonal expansion in MPNs.
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Affiliation(s)
- Hans Carl Hasselbalch
- Department of Hematology, Roskilde Hospital, University of Copenhagen, Koegevej 7-13, 4000 Roskilde, Denmark.
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Bailey LA, Nascarella MA, Kerper LE, Rhomberg LR. Hypothesis-based weight-of-evidence evaluation and risk assessment for naphthalene carcinogenesis. Crit Rev Toxicol 2015; 46:1-42. [PMID: 26202831 PMCID: PMC4732411 DOI: 10.3109/10408444.2015.1061477] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2015] [Accepted: 06/09/2015] [Indexed: 11/13/2022]
Abstract
Inhalation of naphthalene causes olfactory epithelial nasal tumors in rats (but not in mice) and benign lung adenomas in mice (but not in rats). The limited available human data have not identified an association between naphthalene exposure and increased respiratory cancer risk. Assessing naphthalene's carcinogenicity in humans, therefore, depends entirely on experimental evidence from rodents. We evaluated the respiratory carcinogenicity of naphthalene in rodents, and its potential relevance to humans, using our Hypothesis-Based Weight-of-Evidence (HBWoE) approach. We systematically and comparatively reviewed data relevant to key elements in the hypothesized modes of action (MoA) to determine which is best supported by the available data, allowing all of the data from each realm of investigation to inform interpretation of one another. Our analysis supports a mechanism that involves initial metabolism of naphthalene to the epoxide, followed by GSH depletion, cytotoxicity, chronic inflammation, regenerative hyperplasia, and tumor formation, with possible weak genotoxicity from downstream metabolites occurring only at high cytotoxic doses, strongly supporting a non-mutagenic threshold MoA in the rat nose. We also conducted a dose-response analysis, based on the likely MoA, which suggests that the rat nasal MoA is not relevant in human respiratory tissues at typical environmental exposures. Our analysis illustrates how a thorough WoE evaluation can be used to support a MoA, even when a mechanism of action cannot be fully elucidated. A non-mutagenic threshold MoA for naphthalene-induced rat nasal tumors should be considered as a basis to determine human relevance and to guide regulatory and risk-management decisions.
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Borgert CJ, Wise K, Becker RA. Modernizing problem formulation for risk assessment necessitates articulation of mode of action. Regul Toxicol Pharmacol 2015; 72:538-51. [DOI: 10.1016/j.yrtph.2015.04.018] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2015] [Revised: 04/17/2015] [Accepted: 04/18/2015] [Indexed: 10/23/2022]
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20
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Van Der Kraak GJ, Hosmer AJ, Hanson ML, Kloas W, Solomon KR. Effects of atrazine in fish, amphibians, and reptiles: an analysis based on quantitative weight of evidence. Crit Rev Toxicol 2015; 44 Suppl 5:1-66. [PMID: 25375889 DOI: 10.3109/10408444.2014.967836] [Citation(s) in RCA: 80] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
A quantitative weight of evidence (WoE) approach was developed to evaluate studies used for regulatory purposes, as well as those in the open literature, that report the effects of the herbicide atrazine on fish, amphibians, and reptiles. The methodology for WoE analysis incorporated a detailed assessment of the relevance of the responses observed to apical endpoints directly related to survival, growth, development, and reproduction, as well as the strength and appropriateness of the experimental methods employed. Numerical scores were assigned for strength and relevance. The means of the scores for relevance and strength were then used to summarize and weigh the evidence for atrazine contributing to ecologically significant responses in the organisms of interest. The summary was presented graphically in a two-dimensional graph which showed the distributions of all the reports for a response. Over 1290 individual responses from studies in 31 species of fish, 32 amphibians, and 8 reptiles were evaluated. Overall, the WoE showed that atrazine might affect biomarker-type responses, such as expression of genes and/or associated proteins, concentrations of hormones, and biochemical processes (e.g. induction of detoxification responses), at concentrations sometimes found in the environment. However, these effects were not translated to adverse outcomes in terms of apical endpoints. The WoE approach provided a quantitative, transparent, reproducible, and robust framework that can be used to assist the decision-making process when assessing environmental chemicals. In addition, the process allowed easy identification of uncertainty and inconsistency in observations, and thus clearly identified areas where future investigations can be best directed.
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Rhomberg L. Hypothesis-Based Weight of Evidence: An Approach to Assessing Causation and its Application to Regulatory Toxicology. RISK ANALYSIS : AN OFFICIAL PUBLICATION OF THE SOCIETY FOR RISK ANALYSIS 2015; 35:1114-24. [PMID: 24724710 DOI: 10.1111/risa.12206] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Other papers in this symposium focus on combining direct observations or measurements of a phenomenon of interest. Here, I consider the distinct problem of integrating diverse kinds of data to address the scientific case for toxicological causation in view of information that usually contains gaps and outright contradictions. Existing weight-of-evidence approaches have been criticized as either too formulaic or too vague, simply calling for professional judgment that is hard to trace to its scientific basis. I discuss an approach-hypothesis-based weight of evidence-that emphasizes articulation of the hypothesized generalizations, their basis, and span of applicability. Hypothesized common processes should be expected to act elsewhere as well-in different species or different tissues-and so outcomes that ought to be affected become part of the evidence evaluation. A compelling hypothesis is one that provides a common unified explanation for observed results. Any apparent exceptions and failures to account for some data must be plausibly explained. Ad hoc additions to the explanations introduced to "save" hypotheses from apparent contradiction weaken the degree to which available data test causal propositions. In the end, we need an "account" of all the results at hand, specifying what is ascribed to hypothesized common causal processes and what to special exceptions, chance, or other factors. Evidence is weighed by considering comparative plausibility of an account including the proposed causal effect versus an alternative that explains all of the results at hand otherwise.
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Lutter R, Abbott L, Becker R, Borgert C, Bradley A, Charnley G, Dudley S, Felsot A, Golden N, Gray G, Juberg D, Mitchell M, Rachman N, Rhomberg L, Solomon K, Sundlof S, Willett K. Improving weight of evidence approaches to chemical evaluations. RISK ANALYSIS : AN OFFICIAL PUBLICATION OF THE SOCIETY FOR RISK ANALYSIS 2015; 35:186-192. [PMID: 25516407 DOI: 10.1111/risa.12277] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Federal and other regulatory agencies often use or claim to use a weight of evidence (WoE) approach in chemical evaluation. Their approaches to the use of WoE, however, differ significantly, rely heavily on subjective professional judgment, and merit improvement. We review uses of WoE approaches in key articles in the peer-reviewed scientific literature, and find significant variations. We find that a hypothesis-based WoE approach, developed by Lorenz Rhomberg et al., can provide a stronger scientific basis for chemical assessment while improving transparency and preserving the appropriate scope of professional judgment. Their approach, while still evolving, relies on the explicit specification of the hypothesized basis for using the information at hand to infer the ability of an agent to cause human health impacts or, more broadly, affect other endpoints of concern. We describe and endorse such a hypothesis-based WoE approach to chemical evaluation.
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Affiliation(s)
- Randall Lutter
- Batten School of Leadership and Public Policy, University of Virginia
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23
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Lymphohematopoietic cancers induced by chemicals and other agents and their implications for risk evaluation: An overview. MUTATION RESEARCH-REVIEWS IN MUTATION RESEARCH 2014; 761:40-64. [PMID: 24731989 DOI: 10.1016/j.mrrev.2014.04.001] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/05/2013] [Revised: 04/02/2014] [Accepted: 04/03/2014] [Indexed: 12/13/2022]
Abstract
Lymphohematopoietic neoplasia are one of the most common types of cancer induced by therapeutic and environmental agents. Of the more than 100 human carcinogens identified by the International Agency for Research on Cancer, approximately 25% induce leukemias or lymphomas. The objective of this review is to provide an introduction into the origins and mechanisms underlying lymphohematopoietic cancers induced by xenobiotics in humans with an emphasis on acute myeloid leukemia, and discuss the implications of this information for risk assessment. Among the agents causing lymphohematopoietic cancers, a number of patterns were observed. Most physical and chemical leukemia-inducing agents such as the therapeutic alkylating agents, topoisomerase II inhibitors, and ionizing radiation induce mainly acute myeloid leukemia through DNA-damaging mechanisms that result in either gene or chromosomal mutations. In contrast, biological agents and a few immunosuppressive chemicals induce primarily lymphoid neoplasms through mechanisms that involve alterations in immune response. Among the environmental agents examined, benzene was clearly associated with acute myeloid leukemia in humans, with increasing but still limited evidence for an association with lymphoid neoplasms. Ethylene oxide and 1,3-butadiene were linked primarily to lymphoid cancers. Although the association between formaldehyde and leukemia remains controversial, several recent evaluations have indicated a potential link between formaldehyde and acute myeloid leukemia. The four environmental agents examined in detail were all genotoxic, inducing gene mutations, chromosomal alterations, and/or micronuclei in vivo. Although it is clear that rapid progress has been made in recent years in our understanding of leukemogenesis, many questions remain for future research regarding chemically induced leukemias and lymphomas, including the mechanisms by which the environmental agents reviewed here induce these diseases and the risks associated with exposures to such agents.
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Golden R, Valentini M. Formaldehyde and methylene glycol equivalence: critical assessment of chemical and toxicological aspects. Regul Toxicol Pharmacol 2014; 69:178-86. [PMID: 24709515 DOI: 10.1016/j.yrtph.2014.03.007] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2013] [Revised: 03/27/2014] [Accepted: 03/28/2014] [Indexed: 10/25/2022]
Abstract
Due largely to the controversy concerning the potential human health effects from exposure to formaldehyde gas in conjunction with the misunderstanding of the well-established equilibrium relationship with its hydrated reaction product, methylene glycol, the concept of chemical equivalence between these two distinctly different chemicals has been adopted by regulatory authorities. Chemical equivalence implies not only that any concentration of methylene glycol under some condition of use would be nearly or completely converted into formaldehyde gas, but also that these two substances would be toxicologically equivalent as well. A relatively simple worst case experiment using 37% formalin (i.e., concentrated methylene glycol) dispels the concept of chemical equivalence and a review of relevant literature demonstrates that methylene glycol has no inherent toxicity apart from whatever concentration of formaldehyde that might be present in equilibrium with such solutions.
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Affiliation(s)
- R Golden
- ToxLogic LLC, Gaithersburg, MD, USA.
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25
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Antiseptic drugs and disinfectants. ACTA ACUST UNITED AC 2014. [DOI: 10.1016/b978-0-444-62635-6.00024-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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26
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Boyer IJ, Heldreth B, Bergfeld WF, Belsito DV, Hill RA, Klaassen CD, Liebler DC, Marks JG, Shank RC, Slaga TJ, Snyder PW, Andersen FA. Amended Safety Assessment of Formaldehyde and Methylene Glycol as Used in Cosmetics. Int J Toxicol 2013; 32:5S-32S. [DOI: 10.1177/1091581813511831] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Formaldehyde and methylene glycol may be used safely in cosmetics if established limits are not exceeded and are safe for use in nail hardeners in the present practices of use and concentration, which include instructions to avoid skin contact. In hair-smoothing products, however, in the present practices of use and concentration, formaldehyde and methylene glycol are unsafe. Methylene glycol is continuously converted to formaldehyde, and vice versa, even at equilibrium, which can be easily shifted by heating, drying, and other conditions to increase the amount of formaldehyde. This rapid, reversible formaldehyde/methylene glycol equilibrium is distinguished from the slow, irreversible release of formaldehyde resulting from the so-called formaldehyde releaser preservatives, which are not addressed in this safety assessment (formaldehyde releasers may continue to be safely used in cosmetics at the levels established in their individual Cosmetic Ingredient Review safety assessments).
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Affiliation(s)
- Ivan J. Boyer
- Cosmetic Ingredient Review Toxicologist, Washington, DC, USA
| | - Bart Heldreth
- Cosmetic Ingredient Review Chemist, Washington, DC, USA
| | | | | | - Ronald A. Hill
- Cosmetic Ingredient Review Expert Panel Member, Washington, DC, USA
| | | | | | - James G. Marks
- Cosmetic Ingredient Review Expert Panel Member, Washington, DC, USA
| | - Ronald C. Shank
- Cosmetic Ingredient Review Expert Panel Member, Washington, DC, USA
| | - Thomas J. Slaga
- Cosmetic Ingredient Review Expert Panel Member, Washington, DC, USA
| | - Paul W. Snyder
- Cosmetic Ingredient Review Expert Panel Member, Washington, DC, USA
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Ye X, Ji Z, Wei C, McHale CM, Ding S, Thomas R, Yang X, Zhang L. Inhaled formaldehyde induces DNA-protein crosslinks and oxidative stress in bone marrow and other distant organs of exposed mice. ENVIRONMENTAL AND MOLECULAR MUTAGENESIS 2013; 54:705-718. [PMID: 24136419 DOI: 10.1002/em.21821] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/22/2013] [Revised: 09/16/2013] [Accepted: 09/16/2013] [Indexed: 06/02/2023]
Abstract
Formaldehyde (FA), a major industrial chemical and ubiquitous environmental pollutant, has been classified as a leukemogen. The causal relationship remains unclear, however, due to limited evidence that FA induces toxicity in bone marrow, the site of leukemia induction, and in other distal organs. Although induction of DNA-protein crosslinks (DPC), a hallmark of FA toxicity, was not previously detected in the bone marrow of FA-exposed rats and monkeys in studies published in the 1980s, our recent studies showed increased DPC in the bone marrow, liver, kidney, and testes of exposed Kunming mice. To confirm these preliminary results, in the current study we exposed BALB/c mice to 0, 0.5, 1.0, and 3.0 mg m(-3) FA (8 hr per day, for 7 consecutive days) by nose-only inhalation and measured DPC levels in bone marrow and other organs of exposed mice. As oxidative stress is a potential mechanism of FA toxicity, we also measured glutathione (GSH), reactive oxygen species (ROS), and malondialdehyde (MDA), in the bone marrow, peripheral blood mononuclear cells, lung, liver, spleen, and testes of exposed mice. Significant dose-dependent increases in DPC, decreases in GSH, and increases in ROS and MDA were observed in all organs examined (except for DPC in lung). Bone marrow was among the organs with the strongest effects for DPC, GSH, and ROS. In conclusion, exposure of mice to FA by inhalation induced genotoxicity and oxidative stress in bone marrow and other organs. These findings strengthen the biological plausibility of FA-induced leukemogenesis and systemic toxicity.
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Affiliation(s)
- Xin Ye
- Laboratory of Environmental Biomedicine, Hubei Key Laboratory of Genetic Regulation and Integrative Biology, College of Life Sciences, Huazhong Normal University, Wuhan, 430079, People's Republic of China
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Rajabli N, Naeimi-Tabeie M, Jahangirrad A, Sedaghat SM, Semnani S, Roshandel G. Epidemiology of leukemia and multiple myeloma in Golestan, Iran. Asian Pac J Cancer Prev 2013; 14:2333-6. [PMID: 23725136 DOI: 10.7314/apjcp.2013.14.4.2333] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The aim of this paper was to present the incidence rates of leukemia and multiple myeloma (MM) in Golestan province located in northeastern Iran during 2004-2009. MATERIALS AND METHODS This was a descriptive cross-sectional study. Data on newly diagnosed (incident) leukemia and MM cases were obtained from collected from Golestan population-based cancer registry. Data was entered into CanReg-4 software. Age standardized incidence rates (ASR) (per 100000 person-years) for leukemia and MM were calculated. Data on Golestan population was obtained from the data of Iranian national census in 2006. RESULTS Totally, 11036 new cancer cases were registered in GPRC from 2004-2009. Leukemia and MM accounted for 693 and 124 of cases, respectively. The mean age in patients with leukemia and MM was 43.8 and 62.4 years, respectively. The ASRs for leukemia among men and women were 10.4 and 7.8, respectively (p<0.001). The ASRs for MM were 2.1 and 2 in men and women, respectively (p=0.93). The rate of leukemia was significantly higher in rural areas (p=0.02) whereas the incidence of MM was higher in urban areas (p<0.001). CONCLUSIONS Our results showed a high incidence rate of leukemia in Golestan province of Iran. The incidence of leukemia was significantly higher in males and residents of rural areas. High exposure to pesticides and other agricultural related products may be a possible explanation for epidemiological pattern of leukemia in this area. Determining and controlling important risk factors, especially environmental factors, of leukemia may lead to decrease in its burden in Golestan province of Iran.
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Affiliation(s)
- Niloofar Rajabli
- Golestan Research Center of Gastroenterology and Hepatology, Golestan University of Medical Sciences, Gorgan, Iran
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Goodman JE, Prueitt RL, Sax SN, Bailey LA, Rhomberg LR. Evaluation of the causal framework used for setting national ambient air quality standards. Crit Rev Toxicol 2013; 43:829-49. [PMID: 24090029 DOI: 10.3109/10408444.2013.837864] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Abstract A scientifically sound assessment of the potential hazards associated with a substance requires a systematic, objective and transparent evaluation of the weight of evidence (WoE) for causality of health effects. We critically evaluated the current WoE framework for causal determination used in the United States Environmental Protection Agency's (EPA's) assessments of the scientific data on air pollutants for the National Ambient Air Quality Standards (NAAQS) review process, including its methods for literature searches; study selection, evaluation and integration; and causal judgments. The causal framework used in recent NAAQS evaluations has many valuable features, but it could be more explicit in some cases, and some features are missing that should be included in every WoE evaluation. Because of this, it has not always been applied consistently in evaluations of causality, leading to conclusions that are not always supported by the overall WoE, as we demonstrate using EPA's ozone Integrated Science Assessment as a case study. We propose additions to the NAAQS causal framework based on best practices gleaned from a previously conducted survey of available WoE frameworks. A revision of the NAAQS causal framework so that it more closely aligns with these best practices and the full and consistent application of the framework will improve future assessments of the potential health effects of criteria air pollutants by making the assessments more thorough, transparent, and scientifically sound.
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Bone marrow injury induced via oxidative stress in mice by inhalation exposure to formaldehyde. PLoS One 2013; 8:e74974. [PMID: 24040369 PMCID: PMC3770590 DOI: 10.1371/journal.pone.0074974] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2013] [Accepted: 08/11/2013] [Indexed: 01/10/2023] Open
Abstract
OBJECTIVE Formaldehyde, a ubiquitous environmental pollutant has been classified as a human leukemogen. However, toxicity of formaldehyde in bone marrow, the target site of leukemia induction, is still poorly understood. METHODOLOGY/PRINCIPAL FINDINGS To investigate bone marrow toxicity (bone marrow pathology, hematotoxicity) and underlying mechanisms (oxidative stress, inflammation, apoptosis) in formaldehyde-exposed mice. Male Balb/c mice were exposed to formaldehyde (0, 0.5, and 3.0 mg/m(3)) by nose-only inhalation for 8 hours/day, over a two week period designed to simulate a factory work schedule, with an exposure-free "weekend" on days 6 and 7, and were sacrificed on the morning of day 13. Counts of white blood cells, red blood cells and lymphocytes were significantly (p<0.05) decreased at 0.5 mg/m(3) (43%, 7%, and 39%, respectively) and 3.0 mg/m(3) (52%, 27%, and 43%, respectively) formaldehyde exposure, while platelet counts were significantly increased by 109% (0.5 mg/m(3)) and 67% (3.0 mg/m(3)). Biomarkers of oxidative stress (reactive oxygen species, glutathione depletion, cytochrome P450 1A1 and glutathione s-transferase theta 1 expression), inflammation (nuclear factor kappa-B, tomour necrosis factor alpha, interleukin-1 beta), and apoptosis (activity of cysteine-aspartic acid protease 3) in bone marrow tissues were induced at one or both formaldehyde doses mentioned above. CONCLUSIONS/SIGNIFICANCE Exposure of mice to formaldehyde by inhalation induced bone marrow toxicity, and that oxidative stress, inflammation and the consequential apoptosis jointly constitute potential mechanisms of such induced toxicity.
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Vandenberg LN, Colborn T, Hayes TB, Heindel JJ, Jacobs DR, Lee DH, Myers JP, Shioda T, Soto AM, vom Saal FS, Welshons WV, Zoeller RT. Regulatory decisions on endocrine disrupting chemicals should be based on the principles of endocrinology. Reprod Toxicol 2013; 38:1-15. [PMID: 23411111 PMCID: PMC3902067 DOI: 10.1016/j.reprotox.2013.02.002] [Citation(s) in RCA: 132] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2012] [Revised: 01/18/2013] [Accepted: 02/01/2013] [Indexed: 02/05/2023]
Abstract
For years, scientists from various disciplines have studied the effects of endocrine disrupting chemicals (EDCs) on the health and wellbeing of humans and wildlife. Some studies have specifically focused on the effects of low doses, i.e. those in the range that are thought to be safe for humans and/or animals. Others have focused on the existence of non-monotonic dose-response curves. These concepts challenge the way that chemical risk assessment is performed for EDCs. Continued discussions have clarified exactly what controversies and challenges remain. We address several of these issues, including why the study and regulation of EDCs should incorporate endocrine principles; what level of consensus there is for low dose effects; challenges to our understanding of non-monotonicity; and whether EDCs have been demonstrated to produce adverse effects. This discussion should result in a better understanding of these issues, and allow for additional dialog on their impact on risk assessment.
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Affiliation(s)
- Laura N Vandenberg
- Center for Regenerative & Developmental Biology, and Department of Biology, Tufts University, Medford, MA, United States.
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James RC, Britt J, Halmes NC, Guzelian PS. Comments on recent discussions providing differing causation methodologies. Hum Exp Toxicol 2013; 33:109-12. [DOI: 10.1177/0960327113491511] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Affiliation(s)
- RC James
- ToxStrategies, Inc., Tallahassee, Florida, USA
| | - J Britt
- ToxStrategies, Inc., Tallahassee, Florida, USA
| | - NC Halmes
- Halmes and Associates, Centennial, Colorado, USA
| | - PS Guzelian
- University of Colorado Health Sciences Center, Clinical Toxicology (Private Office), Centennial, Colorado, USA
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Prueitt RL, Rhomberg LR, Goodman JE. Hypothesis-based weight-of-evidence evaluation of the human carcinogenicity of toluene diisocyanate. Crit Rev Toxicol 2013; 43:391-435. [DOI: 10.3109/10408444.2013.790877] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
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Pemberton M, Bailey LA, Rhomberg LR. Hypothesis-based weight-of-evidence evaluation of methyl methacrylate olfactory effects in humans and derivation of an occupational exposure level. Regul Toxicol Pharmacol 2013; 66:217-33. [PMID: 23583434 DOI: 10.1016/j.yrtph.2013.04.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2012] [Revised: 03/08/2013] [Accepted: 04/01/2013] [Indexed: 11/15/2022]
Abstract
Over 40 years of scientific evidence indicates that methyl methacrylate (MMA) causes olfactory effects in rodents that are relevant to humans. More recent scientific studies have focused on understanding the apparent lack of species concordance between the rodent and human studies. Toxicokinetic studies and a physiologically based pharmacokinetic (PBPK) model describing inhalation dosimetry of MMA in the upper respiratory tract (URT) of rats and humans point to differences in nasal morphology and biochemistry that could explain and reconcile these differences as species-specific manifestations of a common toxicological process. We have applied the hypothesis-based weight-of-evidence (HBWoE) approach to evaluate the concordance of the available data and the hypothesis that the observed difference in sensitivity between rats and humans may be the expected result of physiological and biochemical differences. Our WoE analysis indicates that when the several lines of evidence (i.e., animal, human, mode-of-action, and toxicokinetics data) are integrated, they inform interpretation of one another and, overall, support use of the human data for derivation of an MMA occupational exposure level (OEL) of 50 ppm.
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Affiliation(s)
- Mark Pemberton
- Systox Limited, 84 Hazelwood Road, Wilmslow, Cheshire SK92QA, United Kingdom.
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Mitkus RJ, Hess MA, Schwartz SL. Pharmacokinetic modeling as an approach to assessing the safety of residual formaldehyde in infant vaccines. Vaccine 2013; 31:2738-43. [PMID: 23583892 DOI: 10.1016/j.vaccine.2013.03.071] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2012] [Revised: 03/05/2013] [Accepted: 03/31/2013] [Indexed: 02/08/2023]
Abstract
Formaldehyde is a one-carbon, highly water-soluble aldehyde that is used in certain vaccines to inactivate viruses and to detoxify bacterial toxins. As part of the manufacturing process, some residual formaldehyde can remain behind in vaccines at levels less than or equal to 0.02%. Environmental and occupational exposure, principally by inhalation, is a continuing risk assessment focus for formaldehyde. However, exposure to formaldehyde via vaccine administration is qualitatively and quantitatively different from environmental or occupational settings and calls for a different perspective and approach to risk assessment. As part of a rigorous and ongoing process of evaluating the safety of biological products throughout their lifecycle at the FDA, we performed an assessment of formaldehyde in infant vaccines, in which estimates of the concentrations of formaldehyde in blood and total body water following exposure to formaldehyde-containing vaccines at a single medical visit were compared with endogenous background levels of formaldehyde in a model 2-month-old infant. Formaldehyde levels were estimated using a physiologically-based pharmacokinetic (PBPK) model of formaldehyde disposition following intramuscular (IM) injection. Model results indicated that following a single dose of 200 μg, formaldehyde is essentially completely removed from the site of injection within 30 min. Assuming metabolism at the site of injection only, peak concentrations of formaldehyde in blood/total body water were estimated to be 22 μg/L, which is equivalent to a body burden of 66 μg or <1% of the endogenous level of formaldehyde. Predicted levels in the lymphatics were even lower. Assuming no adverse effects from endogenous formaldehyde, which exists in blood and extravascular water at background concentrations of 0.1 mM, we conclude that residual, exogenously applied formaldehyde continues to be safe following incidental exposures from infant vaccines.
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Affiliation(s)
- Robert J Mitkus
- Office of Biostatistics and Epidemiology, USFDA Center for Biologics Evaluation and Research, 1401 Rockville Pike, HFM-210, Rockville, MD 20852, USA.
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Ladeira C, Viegas S, Carolino E, Gomes MC, Brito M. The influence of genetic polymorphisms in XRCC3 and ADH5 genes on the frequency of genotoxicity biomarkers in workers exposed to formaldehyde. ENVIRONMENTAL AND MOLECULAR MUTAGENESIS 2013; 54:213-221. [PMID: 23355119 DOI: 10.1002/em.21755] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/13/2012] [Revised: 11/08/2012] [Accepted: 11/14/2012] [Indexed: 06/01/2023]
Abstract
The International Agency for Research on Cancer classified formaldehyde as carcinogenic to humans because there is "sufficient epidemiological evidence that it causes nasopharyngeal cancer in humans". Genes involved in DNA repair and maintenance of genome integrity are critically involved in protecting against mutations that lead to cancer and/or inherited genetic disease. Association studies have recently provided evidence for a link between DNA repair polymorphisms and micronucleus (MN) induction. We used the cytokinesis-block micronucleus (CBMN assay) in peripheral lymphocytes and MN test in buccal cells to investigate the effects of XRCC3 Thr241Met, ADH5 Val309Ile, and Asp353Glu polymorphisms on the frequency of genotoxicity biomarkers in individuals occupationally exposed to formaldehyde (n = 54) and unexposed workers (n = 82). XRCC3 participates in DNA double-strand break/recombination repair, while ADH5 is an important component of cellular metabolism for the elimination of formaldehyde. Exposed workers had significantly higher frequencies (P < 0.01) than controls for all genotoxicity biomarkers evaluated in this study. Moreover, there were significant associations between XRCC3 genotypes and nuclear buds, namely XRCC3 Met/Met (OR = 3.975, CI 1.053-14.998, P = 0.042) and XRCC3 Thr/Met (OR = 5.632, CI 1.673-18.961, P = 0.005) in comparison with XRCC3 Thr/Thr. ADH5 polymorphisms did not show significant effects. This study highlights the importance of integrating genotoxicity biomarkers and genetic polymorphisms in human biomonitoring studies.
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Affiliation(s)
- Carina Ladeira
- Escola Superior de Tecnologia da Saúde de Lisboa - Instituto Politécnico de Lisboa, Portugal.
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von Stackelberg K. A Systematic Review of Carcinogenic Outcomes and Potential Mechanisms from Exposure to 2,4-D and MCPA in the Environment. J Toxicol 2013; 2013:371610. [PMID: 23533401 PMCID: PMC3600329 DOI: 10.1155/2013/371610] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2012] [Revised: 05/18/2012] [Accepted: 07/11/2012] [Indexed: 12/21/2022] Open
Abstract
Chlorophenoxy compounds, particularly 2,4-dichlorophenoxyacetic acid (2,4-D) and 4-chloro-2-methylphenoxy)acetic acid (MCPA), are amongst the most widely used herbicides in the United States for both agricultural and residential applications. Epidemiologic studies suggest that exposure to 2,4-D and MCPA may be associated with increased risk non-Hodgkins lymphoma (NHL), Hodgkin's disease (HD), leukemia, and soft-tissue sarcoma (STS). Toxicological studies in rodents show no evidence of carcinogenicity, and regulatory agencies worldwide consider chlorophenoxies as not likely to be carcinogenic or unclassifiable as to carcinogenicity. This systematic review assembles the available data to evaluate epidemiologic, toxicological, pharmacokinetic, exposure, and biomonitoring studies with respect to key cellular events noted in disease etiology and how those relate to hypothesized modes of action for these constituents to determine the plausibility of an association between exposure to environmentally relevant concentrations of 2,4-D and MCPA and lymphohematopoietic cancers. The combined evidence does not support a genotoxic mode of action. Although plausible hypotheses for other carcinogenic modes of action exist, a comparison of biomonitoring data to oral equivalent doses calculated from bioassay data shows that environmental exposures are not sufficient to support a causal relationship. Genetic polymorphisms exist that are known to increase the risk of developing NHL. The potential interaction between these polymorphisms and exposures to chlorophenoxy compounds, particularly in occupational settings, is largely unknown.
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Affiliation(s)
- Katherine von Stackelberg
- E Risk Sciences, LLP, 12 Holton Street, Allston, MA 02134, USA
- Harvard Center for Risk Analysis, 401 Park Drive, Landmark 404J, Boston, MA 02215, USA
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Nielsen GD, Larsen ST, Wolkoff P. Recent trend in risk assessment of formaldehyde exposures from indoor air. Arch Toxicol 2013; 87:73-98. [PMID: 23179754 PMCID: PMC3618407 DOI: 10.1007/s00204-012-0975-3] [Citation(s) in RCA: 74] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2012] [Accepted: 10/31/2012] [Indexed: 01/09/2023]
Abstract
Studies about formaldehyde (FA) published since the guideline of 0.1 mg/m(3) by the World Health Organization (WHO) in 2010 have been evaluated; critical effects were eye and nasal (portal-of-entry) irritation. Also, it was considered to prevent long-term effects, including all types of cancer. The majority of the recent toxicokinetic studies showed no exposure-dependent FA-DNA adducts outside the portal-of-entry area and FA-DNA adducts at distant sites were due to endogenously generated FA. The no-observed-adverse-effect level for sensory irritation was 0.5 ppm and recently reconfirmed in hypo- and hypersensitive individuals. Investigation of the relationship between FA exposure and asthma or other airway effects in children showed no convincing association. In rats, repeated exposures showed no point mutation in the p53 and K-Ras genes at ≤15 ppm neither increased cell proliferation, histopathological changes and changes in gene expression at 0.7 ppm. Repeated controlled exposures (0.5 ppm with peaks at 1 ppm) did not increase micronucleus formation in human buccal cells or nasal tissue (0.7 ppm) or in vivo genotoxicity in peripheral blood lymphocytes (0.7 ppm), but higher occupational exposures were associated with genotoxicity in buccal cells and cultivated peripheral blood lymphocytes. It is still valid that exposures not inducing nasal squamous cell carcinoma in rats will not induce nasopharyngeal cancer or lymphohematopoietic malignancies in humans. Reproductive and developmental toxicity are not considered relevant in the absence of sensory irritation. In conclusion, the WHO guideline has been strengthened.
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Affiliation(s)
- Gunnar Damgård Nielsen
- National Research Centre for the Working Environment, Lersø Parkallé 105, 2100 Copenhagen, Denmark.
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Fritzsche FR, Ramach C, Soldini D, Caduff R, Tinguely M, Cassoly E, Moch H, Stewart A. Occupational health risks of pathologists--results from a nationwide online questionnaire in Switzerland. BMC Public Health 2012; 12:1054. [PMID: 23216705 PMCID: PMC3538703 DOI: 10.1186/1471-2458-12-1054] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2012] [Accepted: 12/03/2012] [Indexed: 12/25/2022] Open
Abstract
BACKGROUND Pathologists are highly trained medical professionals who play an essential part in the diagnosis and therapy planning of malignancies and inflammatory diseases. Their work is associated with potential health hazards including injuries involving infectious human tissue, chemicals which are assumed to be carcinogenic or long periods of microscope and computer work. This study aimed to provide the first comprehensive assessment of the health situation of pathologists in Switzerland. METHODS Pathologists in Switzerland were contacted via the Swiss Society of Pathologists and asked to answer an ethically approved, online anonymous questionnaire comprising 48 questions on occupational health problems, workplace characteristics and health behaviour. RESULTS 163 pathologists participated in the study. Forty percent of pathologists reported musculoskeletal problems in the previous month. The overall prevalence was 76%. Almost 90% of pathologists had visual refraction errors, mainly myopia. 83% of pathologists had experienced occupational injuries, mostly cutting injuries, in their professional career; more than one fifth of participants reported cutting injuries in the last year. However, long lasting injuries and infectious diseases were rare. Depression and burnout affected every eighth pathologist. The prevalence of smoking was substantially below that of the general Swiss population. CONCLUSIONS The results of this study suggest that more care should be taken in technical and personal protective measures, ergonomic workplace optimisation and reduction of work overload and work inefficiencies. Despite the described health risks, Swiss pathologists were optimistic about their future and their working situation. The high rate of ametropia and psychological problems warrants further study.
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Fox JM, Shuttleworth G, Martin F. Methodology to reduce formaldehyde exposure during laboratory fumigation. INTERNATIONAL JOURNAL OF ENVIRONMENTAL HEALTH RESEARCH 2012; 23:400-406. [PMID: 23163567 DOI: 10.1080/09603123.2012.743114] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Laboratory fumigations achieve disinfection and are performed following the non-contained release of infectious agents. Gaseous formaldehyde remains the most commonly used fumigant but evidence relates formaldehyde exposure to the development of nasopharyngeal cancer. Laboratory personnel must be confident and competent in the procedure to protect themselves, others and the environment. The present study outlines methodology to reduce worker exposure to formaldehyde during essential fumigation training. A simulation fumigation protocol significantly shorter than a genuine fumigation was devised using aromatic cajuput oil to train staff in the fumigation technique without potentially harmful exposure to formaldehyde. Personnel reported increased confidence and compliance of the fumigation procedure after the simulation suggesting that this model protocol would be a valuable training tool for any individual that may be required to undertake genuine formaldehyde fumigations.
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Affiliation(s)
- James Martin Fox
- a Centre for Immunology and Infection, Department of Biology and Hull York Medical School , Wentworth Way, Heslington, University of York , York , UK
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41
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Critical review and synthesis of the epidemiologic evidence on formaldehyde exposure and risk of leukemia and other lymphohematopoietic malignancies. Cancer Causes Control 2012; 23:1747-66. [PMID: 22983399 PMCID: PMC3465649 DOI: 10.1007/s10552-012-0055-2] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2012] [Accepted: 08/14/2012] [Indexed: 12/22/2022]
Abstract
Purpose Recent epidemiologic studies indicate elevated risks for some lymphohematopoietic malignancies (LHM) related to formaldehyde exposure. We performed a systematic review of literature to assess the strength and consistency of associations. Methods We summarized published literature in the PubMed database of the National Library of Medicine during 1966–2012. Literature was categorized according to study design and population: industrial cohort studies, professional cohort studies, and population-based case–control studies. Results Findings from occupational cohort and population-based case–control studies were very inconsistent for LHM, including myeloid leukemia. Apart from some isolated exceptions, relative risks were close to the null, and there was little evidence for dose–response relations for any of the LHM. Conclusions At present, there is no consistent or strong epidemiologic evidence that formaldehyde is causally related to any of the LHM. The absence of established toxicological mechanisms further weakens any arguments for causation. To be informative, future epidemiologic research should improve on formaldehyde exposure assessment and apply modern diagnostic schemes for specific LHM.
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Goodman JE, Prueitt RL, Rhomberg LR. Incorporating Low-Dose Epidemiology Data in a Chlorpyrifos Risk Assessment. Dose Response 2012. [DOI: 10.2203/dose-response.12-022.goodman] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
USEPA assessed whether epidemiology data suggest that fetal or early-life chlorpyrifos exposure causes neurodevelopmental effects and, if so, whether they occur at exposures below those causing the current most sensitive endpoint, 10% inhibition of blood acetyl-cholinesterase (AChE). We previously conducted a hypothesis-based weight-of-evidence analysis and found that a proposed causal association between chlorpyrifos exposure and neurodevelopmental effects in the absence of AChE inhibition does not have a substantial basis in existing animal or in vitro studies, and there is no plausible basis for invoking such effects in humans at their far lower exposure levels. The epidemiology studies fail to show consistent patterns; the few associations are likely attributable to alternative explanations. Human data are inappropriate for a dose-response assessment because biomarkers were only measured at one time point, may reflect exposure to other pesticides, and many values are at or below limits of quantification. When considered with pharmacokinetic data, however, these biomarkers provide information on exposure levels relative to those in experimental studies and indicate a margin of exposure of at least 1,000. Because animal data take into account the most sensitive lifestages, the use of AChE inhibition as a regulatory endpoint is protective of adverse effects in sensitive populations.
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43
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Goodman JE, Prueitt RL, Rhomberg LR. Incorporating Low-dose Epidemiology Data in a Chlorpyrifos Risk Assessment. Dose Response 2012; 11:207-19. [PMID: 23930102 PMCID: PMC3682198 DOI: 10.2203/doseresponse.12022.goodman] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
USEPA assessed whether epidemiology data suggest that fetal or early-life chlorpyrifos exposure causes neurodevelopmental effects and, if so, whether they occur at exposures below those causing the current most sensitive endpoint, 10% inhibition of blood acetylcholinesterase (AChE). We previously conducted a hypothesis-based weight-of-evidence analysis and found that a proposed causal association between chlorpyrifos exposure and neurodevelopmental effects in the absence of AChE inhibition does not have a substantial basis in existing animal or in vitro studies, and there is no plausible basis for invoking such effects in humans at their far lower exposure levels. The epidemiology studies fail to show consistent patterns; the few associations are likely attributable to alternative explanations. Human data are inappropriate for a dose-response assessment because biomarkers were only measured at one time point, may reflect exposure to other pesticides, and many values are at or below limits of quantification. When considered with pharmacokinetic data, however, these biomarkers provide information on exposure levels relative to those in experimental studies and indicate a margin of exposure of at least 1,000. Because animal data take into account the most sensitive lifestages, the use of AChE inhibition as a regulatory endpoint is protective of adverse effects in sensitive populations.
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Rhomberg LR, Goodman JE, Foster WG, Borgert CJ, Van Der Kraak G. A critique of the European Commission document, "State of the Art Assessment of Endocrine Disrupters". Crit Rev Toxicol 2012; 42:465-73. [PMID: 22630047 PMCID: PMC3408894 DOI: 10.3109/10408444.2012.690367] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2012] [Revised: 04/27/2012] [Accepted: 04/30/2012] [Indexed: 01/05/2023]
Abstract
In this commentary, we critique a recently finalized document titled "State of the Art Assessment of Endocrine Disrupters" (SOA Assessment). The SOA Assessment was commissioned by the European Union Directorate-General for the Environment to provide a basis for developing scientific criteria for identifying endocrine disruptors and reviewing and possibly revising the European Community Strategy on Endocrine Disrupters. In our view, the SOA Assessment takes an anecdotal approach rather than attempting a comprehensive assessment of the state of the art or synthesis of current knowledge. To do the latter, the document would have had to (i) distinguish between apparent associations of outcomes with exposure and the inference of an endocrine-disruption (ED) basis for those outcomes; (ii) constitute a complete and unbiased survey of new literature since 2002 (when the WHO/IPCS document, "Global Assessment of the State-of-the-Science of Endocrine Disruptors" was published); (iii) consider strengths and weaknesses and issues in interpretation of the cited literature; (iv) follow a weight-of-evidence methodology to evaluate evidence of ED; (v) document the evidence for its conclusions or the reasoning behind them; and (vi) present the evidence for or reasoning behind why conclusions that differ from those drawn in the 2002 WHO/IPCS document need to be changed. In its present form, the SOA Assessment fails to provide a balanced and critical assessment or synthesis of literature relevant to ED. We urge further evidence-based evaluations to develop the needed scientific basis to support future policy decisions.
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Bailey LA, Prueitt RL, Rhomberg LR. Hypothesis-Based Weight-of-Evidence evaluation of methanol as a human carcinogen. Regul Toxicol Pharmacol 2011; 62:278-91. [PMID: 22166730 DOI: 10.1016/j.yrtph.2011.11.015] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2011] [Revised: 11/09/2011] [Accepted: 11/28/2011] [Indexed: 02/07/2023]
Abstract
Recent scientific debate has focused on the potential for exposure to methanol to cause lymphomas in humans. The concern stems from a few animal studies reporting an association, although evidence suggests the studies may have been confounded by chronic respiratory infection. Although the toxicological evidence for methanol carcinogenesis is weak, two modes of action have been put forth, one involving metabolism of methanol to formaldehyde, followed by formaldehyde induction of lymphoma, and another involving oxidative stress caused by hydrogen peroxide release during catalase-induced metabolism of methanol to formaldehyde. In this article, we apply our Hypothesis-Based Weight-of-Evidence (HBWoE) approach to evaluate the evidence regarding methanol exposure and lymphoma, attending to how human, animal, and mode-of-action results inform one another, tracing the logic of inference within and across all studies, and articulating how one could account for the suite of available observations. Upon comparison of alternative proposals regarding what causal processes may have led to the array of observations as we see them, we conclude that the apparent association between methanol exposure and lymphoma in some animal studies is weak and strains biological plausibility, and is better interpreted as due to confounding or to a mechanism not relevant in humans.
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Affiliation(s)
- Lisa A Bailey
- Gradient, 20 University Road, Cambridge, MA 02138, USA.
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Golden R. Identifying an indoor air exposure limit for formaldehyde considering both irritation and cancer hazards. Crit Rev Toxicol 2011; 41:672-721. [PMID: 21635194 PMCID: PMC3175005 DOI: 10.3109/10408444.2011.573467] [Citation(s) in RCA: 83] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2010] [Revised: 03/14/2011] [Accepted: 03/16/2011] [Indexed: 02/06/2023]
Abstract
Formaldehyde is a well-studied chemical and effects from inhalation exposures have been extensively characterized in numerous controlled studies with human volunteers, including asthmatics and other sensitive individuals, which provide a rich database on exposure concentrations that can reliably produce the symptoms of sensory irritation. Although individuals can differ in their sensitivity to odor and eye irritation, the majority of authoritative reviews of the formaldehyde literature have concluded that an air concentration of 0.3 ppm will provide protection from eye irritation for virtually everyone. A weight of evidence-based formaldehyde exposure limit of 0.1 ppm (100 ppb) is recommended as an indoor air level for all individuals for odor detection and sensory irritation. It has recently been suggested by the International Agency for Research on Cancer (IARC), the National Toxicology Program (NTP), and the US Environmental Protection Agency (US EPA) that formaldehyde is causally associated with nasopharyngeal cancer (NPC) and leukemia. This has led US EPA to conclude that irritation is not the most sensitive toxic endpoint and that carcinogenicity should dictate how to establish exposure limits for formaldehyde. In this review, a number of lines of reasoning and substantial scientific evidence are described and discussed, which leads to a conclusion that neither point of contact nor systemic effects of any type, including NPC or leukemia, are causally associated with exposure to formaldehyde. This conclusion supports the view that the equivocal epidemiology studies that suggest otherwise are almost certainly flawed by identified or yet to be unidentified confounding variables. Thus, this assessment concludes that a formaldehyde indoor air limit of 0.1 ppm should protect even particularly susceptible individuals from both irritation effects and any potential cancer hazard.
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