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Austigard ÅD, Smedbold HT, von Hirsch Svendsen K. Comparison of 3 methods characterizing H2S exposure in water and wastewater management work. Ann Work Expo Health 2024:wxae043. [PMID: 38981129 DOI: 10.1093/annweh/wxae043] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2023] [Accepted: 05/02/2024] [Indexed: 07/11/2024] Open
Abstract
This study evaluates the effectiveness of self-assessed exposure (SAE) data collection for characterization of hydrogen sulfide (H2S) risks in water and wastewater management, challenging the adequacy of traditional random or campaign sampling strategies. We compared 3 datasets derived from distinct strategies: expert data with activity metadata (A), SAE without metadata (B), and SAE with logbook metadata (C). The findings reveal that standard practices of random sampling (dataset A) fail to capture the sporadic nature of H2S exposure. Instead, SAE methods enhanced by logbook metadata and supported by reliable detection and calibration infrastructure (datasets B and C) are more effective. When assessing risk, particularly peak exposure risks, it is crucial to adopt measures that capture exposure variability, such as the range and standard deviations. This finer assessment is vital where high H2S peaks occur in confined spaces. Risk assessment should incorporate indices that account for peak exposure, utilizing variability measures like range and standard or geometric standard deviation to reflect the actual risk more accurately. For large datasets, a histogram is just as useful as statistical measures. This approach has revealed that not only wastewater workers but also water distribution network workers, can face unexpectedly high H2S levels when accessing confined underground spaces. Our research underscores the need for continuous monitoring with personal electrochemical gas detector alarm systems, particularly in environments with variable and potentially hazardous exposure levels.
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Affiliation(s)
- Åse Dalseth Austigard
- Department of Industrial Economics and Technology Management, NTNU - Norwegian University of Science and Technology, PO Box 8900, Torgarden, N-7491 Trondheim, Norway
- Trondheim Municipality, Working Environment Office, PO Box 2300, Torgarden, N-7004 Trondheim, Norway
| | - Hans Thore Smedbold
- Department of Occupational Medicine, St Olav University Hospital, PO Box 3250, Torgarden, N-7006 Trondheim, Norway
- Department of Public Health and Nursing, Faculty of Medicine and Health Sciences, NTNU, PO Box 8900, Torgarden, N-7491 Trondheim, Norway
| | - Kristin von Hirsch Svendsen
- Department of Industrial Economics and Technology Management, NTNU - Norwegian University of Science and Technology, PO Box 8900, Torgarden, N-7491 Trondheim, Norway
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Maurer LL, Alexander MS, Bachman AN, Grimm FA, Lewis RJ, North CM, Wojcik NC, Goyak KO. An interdisciplinary framework for derivation of occupational exposure limits. Front Public Health 2022; 10:1038305. [PMID: 36530659 PMCID: PMC9748553 DOI: 10.3389/fpubh.2022.1038305] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2022] [Accepted: 11/14/2022] [Indexed: 12/03/2022] Open
Abstract
Protecting the health and safety of workers in industrial operations is a top priority. One of the resources used in industry to ensure worker safety is the occupational exposure limit (OEL). OELs are derived from the assessment and interpretation of empirical data from animal and/or human studies. There are various guidelines for the derivation and implementation of OELs globally, with a range of stakeholders (including regulatory bodies, governmental agencies, expert groups and others). The purpose of this manuscript is to supplement existing guidance with learnings from a multidisciplinary team approach within an industry setting. The framework we present is similar in construct to other risk assessment frameworks and includes: (1) problem formulation, (2) literature review, (3) weight of evidence considerations, (4) point of departure selection/derivation, (5) application of assessment factors, and the final step, (6) derivation of the OEL. Within each step are descriptions and examples to consider when incorporating data from various disciplines such as toxicology, epidemiology, and exposure science. This manuscript describes a technical framework by which available data relevant for occupational exposures is compiled, analyzed, and utilized to inform safety threshold derivation applicable to OELs.
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Toxicological Effects of Technical Xylene Mixtures on the Female Reproductive System: A Systematic Review. TOXICS 2022; 10:toxics10050235. [PMID: 35622648 PMCID: PMC9144477 DOI: 10.3390/toxics10050235] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/04/2022] [Revised: 04/29/2022] [Accepted: 05/02/2022] [Indexed: 02/04/2023]
Abstract
Technical xylene is a compound of massive production that is used in applications such as petrochemical and healthcare laboratories. Exposure to xylene can cause acute and chronic effects in humans and animals. Currently available studies regarding xylene’s adverse effects with credible designs were dated almost twenty years ago. This systematic review summarizes the findings regarding the detrimental effects of technical xylene from human, animal, and in vitro studies. It recapitulated available studies with respect to the effects of xylene on the female reproductive system to stress the need for updating the current data and guidelines. Based on pre-specified criteria, 22 studies from journal databases exploring the toxic effects of xylene on menstruation, endocrine endpoints, fetal development, and reproductive functions were included for the review. It was found that related studies with a specific focus on the effects of technical xylene on the female reproductive system were insufficient. Therefore, further studies are necessary to update the existing data, thus improving the quality and reliability of risk assessment of exposure to xylene in pregnant women
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4
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Ahuja V, Krishnappa M. Approaches for setting occupational exposure limits in the pharmaceutical industry. J Appl Toxicol 2021; 42:154-167. [PMID: 34254327 DOI: 10.1002/jat.4218] [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: 03/12/2021] [Revised: 06/26/2021] [Accepted: 06/26/2021] [Indexed: 11/09/2022]
Abstract
The use of pharmaceutical drugs has provided a cure for many diseases. However, unintended exposure to drugs in the manufacturing workplace can cause significant health hazards to workers. It is important to protect the workforce from these deleterious effects by limiting exposure to an acceptable level, the occupational exposure limit (OEL). OEL is defined as airborne concentrations (expressed as a time-weighted average for a conventional 8-h workday and a 40-h work week) of a substance to which nearly all workers may be repeatedly exposed (for a working lifetime) without adverse effects. Determination of OELs has become very challenging over time, requiring an overall assessment of the preclinical and clinical data of the drug being manufactured. Previously, to derive OEL values, toxicologists used animal no-observed-adverse-effect level (NOAEL) data, which have been replaced with the overall assessment of animal and human data, placing a higher emphasis on human health-based data. A major advantage of working with human pharmaceuticals is that sufficient clinical data are available for them in most cases. The present manuscript reviews the latest knowledge regarding the derivation of occupational exposure limits as health-based exposure limits (HBELs) for pharmaceuticals. We have provided examples of OEL calculations for various drugs including levofloxacin (CAS No. 100986-85-4), dienogest (CAS no. 65928-58-7), and acetylsalicylic acid (ASA, CAS no. 50-78-2) using human data. This report will benefit professionals in the OEL domain in understanding this highly important, growing, and challenging field.
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Affiliation(s)
- Varun Ahuja
- Safety Assessment Department, Syngene International Limited, Bangalore, India
| | - Mohan Krishnappa
- Safety Assessment Department, Syngene International Limited, Bangalore, India
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Baralić K, Javorac D, Antonijević E, Buha-Đorđević A, Ćurčić M, Đukić-Ćosić D, Bulat Z, Antonijević B. Relevance and evaluation of the benchmark dose in toxicology. ARHIV ZA FARMACIJU 2020. [DOI: 10.5937/arhfarm2003130b] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
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Jensen SM, Kluxen FM, Ritz C. A Review of Recent Advances in Benchmark Dose Methodology. RISK ANALYSIS : AN OFFICIAL PUBLICATION OF THE SOCIETY FOR RISK ANALYSIS 2019; 39:2295-2315. [PMID: 31046141 DOI: 10.1111/risa.13324] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2018] [Revised: 02/01/2019] [Accepted: 04/03/2019] [Indexed: 06/09/2023]
Abstract
In this review, recent methodological developments for the benchmark dose (BMD) methodology are summarized. Specifically, we introduce the advances for the main steps in BMD derivation: selecting the procedure for defining a BMD from a predefined benchmark response (BMR), setting a BMR, selecting a dose-response model, and estimating the corresponding BMD lower limit (BMDL). Although the last decade has shown major progress in the development of BMD methodology, there is still room for improvement. Remaining challenges are the implementation of new statistical methods in user-friendly software and the lack of consensus about how to derive the BMDL.
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Affiliation(s)
- Signe M Jensen
- Department of Plant and Environmental Sciences, University of Copenhagen, Copenhagen, Denmark
| | | | - Christian Ritz
- Department of Nutrition, Sports and Exercise, University of Copenhagen, Copenhagen, Denmark
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7
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Chebekoue SF, Krishnan K. Derivation of internal dose-based thresholds of toxicological concern for occupational inhalation exposure to systemically acting organic chemicals. JOURNAL OF OCCUPATIONAL AND ENVIRONMENTAL HYGIENE 2019; 16:308-319. [PMID: 30676257 DOI: 10.1080/15459624.2019.1568445] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
This study aimed at deriving occupational thresholds of toxicological concern for inhalation exposure to systemically-acting organic chemicals using predicted internal doses. The latter were also used to evaluate the quantitative relationship between occupational exposure limit and internal dose. Three internal dose measures were identified for investigation: (i) the daily area under the venous blood concentration vs. time curve, (ii) the daily rate of the amount of parent chemical metabolized, and (iii) the maximum venous blood concentration at the end of an 8-hr work shift. A dataset of 276 organic chemicals with 8-hr threshold limit values-time-weighted average was compiled along with their molecular structure and Cramer classes (Class I: low toxicity, Class II: intermediate toxicity, Class III: suggestive of significant toxicity). Using a human physiologically-based pharmacokinetic model, the three identified dose metrics were predicted for an 8-hr occupational inhalation exposure to the threshold limit value for each chemical. Distributional analyses of the predicted dose metrics were performed to identify the percentile values corresponding to the occupational thresholds of toxicological concern. Also, simple linear regression analyses were performed to evaluate the relationship between the 8-hr threshold limit value and each of the predicted dose metrics, respectively. No threshold of toxicological concern could be derived for class II due to few chemicals. Based on the daily rate of the amount of parent chemical metabolized, the proposed internal dose-based occupational thresholds of toxicological concern were 5.61 × 10-2 and 9 × 10-4 mmol/d at the 10th percentile level for classes I and III, respectively, while they were 4.55 × 10-1 and 8.5 × 10-3 mmol/d at the 25th percentile level. Even though high and significant correlations were observed between the 8-hr threshold limit values and the predicted dose metrics, the one with the rate of the amount of chemical metabolized was remarkable regardless of the Cramer class (r2 = 0.81; n = 276). The proposed internal dose-based occupational thresholds of toxicological concern are potentially useful for screening-level assessments as well as prioritization within an integrated occupational risk assessment framework.
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Affiliation(s)
- Sandrine F Chebekoue
- a École de Santé Publique de l'Université de Montréal (ESPUM) , Montréal , Québec , Canada
| | - Kannan Krishnan
- a École de Santé Publique de l'Université de Montréal (ESPUM) , Montréal , Québec , Canada
- b Institut de recherche Robert-Sauvé en santé et en sécurité du travail (IRSST) , Montréal , Québec , Canada
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Beckett EM, Cyrs WD, Abelmann A, Monnot AD, Gaffney SH, Finley BL. Derivation of an occupational exposure limit for diacetyl using dose-response data from a chronic animal inhalation exposure study. J Appl Toxicol 2019; 39:688-701. [PMID: 30620996 DOI: 10.1002/jat.3757] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2018] [Revised: 10/29/2018] [Accepted: 10/30/2018] [Indexed: 11/08/2022]
Abstract
Occupational exposure limits (OELs) have been previously proposed for diacetyl; however, most of these values are based on worker cohort studies that are known to have several limitations and confounders. In this analysis, an 8 hour time-weighted average (TWA) OEL for diacetyl was derived based on data from a chronic, 2 year animal inhalation study recently released by the US National Toxicology Program. In that study, complete histopathology was conducted on male and female mice and rats exposed to 0, 12.5, 25 or 50 ppm diacetyl. Several responses in the lower respiratory tract of rats (the more sensitive species) were chosen as the critical endpoints of interest. Benchmark concentration (BMC) modeling of these endpoints was used to estimate BMC values associated with a 10% extra risk (BMC10 ) and the associated 95% lower confidence bound (BMCL10 ), which were subsequently converted to human equivalent concentrations (HECs) using a computational fluid dynamics-physiologically based pharmacokinetic (CFD-PBPK) model to account for interspecies dosimetry differences. A composite uncertainty factor of 8.0 was applied to the human equivalent concentration values to yield 8 hour TWA OEL values with a range of 0.16-0.70 ppm. The recommended 8 hour TWA OEL for diacetyl vapor of 0.2 ppm, based on minimal severity of bronchiolar epithelial hyperplasia in the rat, is practical and health-protective.
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9
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Hsieh NH, Chung SH, Chen SC, Chen WY, Cheng YH, Lin YJ, You SH, Liao CM. Anemia risk in relation to lead exposure in lead-related manufacturing. BMC Public Health 2017; 17:389. [PMID: 28476140 PMCID: PMC5420139 DOI: 10.1186/s12889-017-4315-7] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2016] [Accepted: 04/26/2017] [Indexed: 12/02/2022] Open
Abstract
Background Lead-exposed workers may suffer adverse health effects under the currently regulated blood lead (BPb) levels. However, a probabilistic assessment about lead exposure-associated anemia risk is lacking. The goal of this study was to examine the association between lead exposure and anemia risk among factory workers in Taiwan. Methods We first collated BPb and indicators of hematopoietic function data via health examination records that included 533 male and 218 female lead-exposed workers between 2012 and 2014. We used benchmark dose (BMD) modeling to estimate the critical effect doses for detection of abnormal indicators. A risk-based probabilistic model was used to characterize the potential hazard of lead poisoning for job-specific workers by hazard index (HI). We applied Bayesian decision analysis to determine whether BMD could be implicated as a suitable BPb standard. Results Our results indicated that HI for total lead-exposed workers was 0.78 (95% confidence interval: 0.50–1.26) with risk occurrence probability of 11.1%. The abnormal risk of anemia indicators for male and female workers could be reduced, respectively, by 67–77% and 86–95% by adopting the suggested BPb standards of 25 and 15 μg/dL. Conclusions We conclude that cumulative exposure to lead in the workplace was significantly associated with anemia risk. This study suggests that current BPb standard needs to be better understood for the application of lead-exposed population protection in different scenarios to provide a novel standard for health management. Low-level lead exposure risk is an occupational and public health problem that should be paid more attention. Electronic supplementary material The online version of this article (doi:10.1186/s12889-017-4315-7) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Nan-Hung Hsieh
- Department of Veterinary Integrative Biosciences, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX, 77845, USA
| | - Shun-Hui Chung
- Institute of Labor, Occupational Safety and Health, Ministry of Labor, New Taipei City, 22143, Taiwan, ROC
| | - Szu-Chieh Chen
- Department of Public Health, Chung Shan Medical University, Taichung, 40242, Taiwan, ROC.,Department of Family and Community Medicine, Chung Shan Medical University Hospital, Taichung, 40242, Taiwan, ROC
| | - Wei-Yu Chen
- Department of Biomedical Science and Environmental Biology, Kaohsiung Medical University, Kaohsiung, 80708, Taiwan, ROC
| | - Yi-Hsien Cheng
- Institute of Computational Comparative Medicine, Department of Anatomy and Physiology, College of Veterinary Medicine, Kansas State University, Manhattan, Kansas, 66506, USA
| | - Yi-Jun Lin
- Department of Bioenvironmental Systems Engineering, National Taiwan University, Taipei, 10617, Taiwan, ROC
| | - Su-Han You
- National Environmental Health Research Center, National Health Research Institutes, Miaoli County, 35053, Taiwan, ROC
| | - Chung-Min Liao
- Department of Bioenvironmental Systems Engineering, National Taiwan University, Taipei, 10617, Taiwan, ROC.
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Vaughan NP, Rajan-Sithamparanadarajah R. An Assessment of the Robustness of the COSHH-Essentials (C-E) Target Airborne Concentration Ranges 15 Years on, and Their Usefulness for Determining Control Measures. Ann Work Expo Health 2017; 61:270-283. [PMID: 28355421 DOI: 10.1093/annweh/wxx002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2016] [Accepted: 02/08/2017] [Indexed: 11/14/2022] Open
Abstract
The Health and Safety Executive (HSE) in Great Britain (GB), in association with its stakeholders, developed the Control of Substances Hazardous to Health (COSHH)-Essentials (C-E) control banding tool in 1998. The objective was to provide a simple tool for employers, particularly small and medium-sized enterprises (SMEs), to help select and apply appropriate measures for the adequate control of exposure to hazardous substances. The tool used hazard classification information (R-phrases) to assign substances to one of five health hazard groups, each with its respective 'target airborne concentration range'. The validity of the allocation of substances to a target airborne concentration range was demonstrated at the time using 111 substances that had a current health-based Occupational Exposure Limit (OEL) in GB. The C-E control banding approach remains an important tool to complement exposure assessment/monitoring and the selection and use of suitable control measures for hazardous substances. These include engineering controls and personal protective equipment (PPE). The C-E based control banding approach has been adopted around the world. This paper extends the original validation exercise, using a greater number of chemical substances, to establish whether the target airborne concentration ranges remain appropriate. This is of particular interest in light of the introduction of the Globally Harmonized System (GHS) for classification, in which R-phrases have now been replaced by hazard-statements (H-statements). The validation exercise includes substances with OELs published by nine bodies internationally; and the Derived No-Effect Levels (DNELs) assigned by registrants under the European Union-Registration, Evaluation, Authorisation and Restriction of Chemicals (REACH) Regulations. When compared against 8-hour TWA OELs for 850 substances drawn from nine bodies and a limited number of DNELS, the C-E target airborne concentration ranges remain valid. This comparative work also informs a wider consideration around the practicality and the applicability of the C-E generic approach to facilitate the implementation of good practice control for a wide range of substances (more than 95%) which do not have any recognized OEL.
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Affiliation(s)
- Nicholas P Vaughan
- Health and Safety Laboratory, Harpur Hill, Buxton, Derbyshire SK17 9JN, UK
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Maier A, Lentz TJ, MacMahon KL, McKernan LT, Whittaker C, Schulte PA. State-of-the-Science: The Evolution of Occupational Exposure Limit Derivation and Application. JOURNAL OF OCCUPATIONAL AND ENVIRONMENTAL HYGIENE 2015; 12 Suppl 1:S4-S6. [PMID: 26110740 PMCID: PMC4654637 DOI: 10.1080/15459624.2015.1060329] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/19/2014] [Accepted: 12/22/2014] [Indexed: 05/31/2023]
Affiliation(s)
- A. Maier
- Department of Environmental Health, University of Cincinnati, Cincinatti, Ohio
| | - T. J. Lentz
- Education and Information Division, National Institute for Occupational Safety and Health, Cincinnati, Ohio
| | - K. L. MacMahon
- Education and Information Division, National Institute for Occupational Safety and Health, Cincinnati, Ohio
| | - L. T. McKernan
- Education and Information Division, National Institute for Occupational Safety and Health, Cincinnati, Ohio
| | - C. Whittaker
- Education and Information Division, National Institute for Occupational Safety and Health, Cincinnati, Ohio
| | - P. A. Schulte
- Education and Information Division, National Institute for Occupational Safety and Health, Cincinnati, Ohio
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12
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Dankovic DA, Naumann BD, Maier A, Dourson ML, Levy LS. The Scientific Basis of Uncertainty Factors Used in Setting Occupational Exposure Limits. JOURNAL OF OCCUPATIONAL AND ENVIRONMENTAL HYGIENE 2015; 12 Suppl 1:S55-68. [PMID: 26097979 PMCID: PMC4643360 DOI: 10.1080/15459624.2015.1060325] [Citation(s) in RCA: 79] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
The uncertainty factor concept is integrated into health risk assessments for all aspects of public health practice, including by most organizations that derive occupational exposure limits. The use of uncertainty factors is predicated on the assumption that a sufficient reduction in exposure from those at the boundary for the onset of adverse effects will yield a safe exposure level for at least the great majority of the exposed population, including vulnerable subgroups. There are differences in the application of the uncertainty factor approach among groups that conduct occupational assessments; however, there are common areas of uncertainty which are considered by all or nearly all occupational exposure limit-setting organizations. Five key uncertainties that are often examined include interspecies variability in response when extrapolating from animal studies to humans, response variability in humans, uncertainty in estimating a no-effect level from a dose where effects were observed, extrapolation from shorter duration studies to a full life-time exposure, and other insufficiencies in the overall health effects database indicating that the most sensitive adverse effect may not have been evaluated. In addition, a modifying factor is used by some organizations to account for other remaining uncertainties-typically related to exposure scenarios or accounting for the interplay among the five areas noted above. Consideration of uncertainties in occupational exposure limit derivation is a systematic process whereby the factors applied are not arbitrary, although they are mathematically imprecise. As the scientific basis for uncertainty factor application has improved, default uncertainty factors are now used only in the absence of chemical-specific data, and the trend is to replace them with chemical-specific adjustment factors whenever possible. The increased application of scientific data in the development of uncertainty factors for individual chemicals also has the benefit of increasing the transparency of occupational exposure limit derivation. Improved characterization of the scientific basis for uncertainty factors has led to increasing rigor and transparency in their application as part of the overall occupational exposure limit derivation process.
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Affiliation(s)
- D. A. Dankovic
- Education and Information Division, Centers for Disease Control and Prevention (CDC), National Institute for Occupational Safety and Health (NIOSH), Cincinnati, Ohio
| | - B. D. Naumann
- Global Safety and the Environment, Merck & Co., Inc., Whitehouse Station, New Jersey
| | - A. Maier
- University of Cincinnati, College of Medicine, Department of Environmental Health, Cincinnati, Ohio
| | - M. L. Dourson
- The Toxicology Excellence for Risk Assessment Center of the University of Cincinnati, College of Medicine, Department of Environmental Health, Toxicology Excellence for Risk Assessment, Cincinnati, Ohio
| | - L. S. Levy
- Institute for Environment, Health, Risks and Futures, Cranfield University, Cranfield, Bedfordshire. United Kingdom
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Waters M, McKernan L, Maier A, Jayjock M, Schaeffer V, Brosseau L. Exposure Estimation and Interpretation of Occupational Risk: Enhanced Information for the Occupational Risk Manager. JOURNAL OF OCCUPATIONAL AND ENVIRONMENTAL HYGIENE 2015; 12 Suppl 1:S99-111. [PMID: 26302336 PMCID: PMC4685553 DOI: 10.1080/15459624.2015.1084421] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
The fundamental goal of this article is to describe, define, and analyze the components of the risk characterization process for occupational exposures. Current methods are described for the probabilistic characterization of exposure, including newer techniques that have increasing applications for assessing data from occupational exposure scenarios. In addition, since the probability of health effects reflects variability in the exposure estimate as well as the dose-response curve-the integrated considerations of variability surrounding both components of the risk characterization provide greater information to the occupational hygienist. Probabilistic tools provide a more informed view of exposure as compared to use of discrete point estimates for these inputs to the risk characterization process. Active use of such tools for exposure and risk assessment will lead to a scientifically supported worker health protection program. Understanding the bases for an occupational risk assessment, focusing on important sources of variability and uncertainty enables characterizing occupational risk in terms of a probability, rather than a binary decision of acceptable risk or unacceptable risk. A critical review of existing methods highlights several conclusions: (1) exposure estimates and the dose-response are impacted by both variability and uncertainty and a well-developed risk characterization reflects and communicates this consideration; (2) occupational risk is probabilistic in nature and most accurately considered as a distribution, not a point estimate; and (3) occupational hygienists have a variety of tools available to incorporate concepts of risk characterization into occupational health and practice.
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Affiliation(s)
- Martha Waters
- Division of Applied Research and Technology, National Institute for Occupational Safety and Health, Cincinnati, Ohio
| | - Lauralynn McKernan
- Education and Information Division, National Institute for Occupational Safety and Health, Cincinnati, Ohio
| | - Andrew Maier
- Department of Environmental Health, University of Cincinnati, Cincinnati, Ohio
| | | | - Val Schaeffer
- Occupational Safety and Health Administration, Washington, DC
| | - Lisa Brosseau
- Environmental & Occupational Health Sciences, University of Illinois at Chicago, Chicago, Illinois
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Kuempel ED, Sweeney LM, Morris JB, Jarabek AM. Advances in Inhalation Dosimetry Models and Methods for Occupational Risk Assessment and Exposure Limit Derivation. JOURNAL OF OCCUPATIONAL AND ENVIRONMENTAL HYGIENE 2015; 12 Suppl 1:S18-40. [PMID: 26551218 PMCID: PMC4685615 DOI: 10.1080/15459624.2015.1060328] [Citation(s) in RCA: 57] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
The purpose of this article is to provide an overview and practical guide to occupational health professionals concerning the derivation and use of dose estimates in risk assessment for development of occupational exposure limits (OELs) for inhaled substances. Dosimetry is the study and practice of measuring or estimating the internal dose of a substance in individuals or a population. Dosimetry thus provides an essential link to understanding the relationship between an external exposure and a biological response. Use of dosimetry principles and tools can improve the accuracy of risk assessment, and reduce the uncertainty, by providing reliable estimates of the internal dose at the target tissue. This is accomplished through specific measurement data or predictive models, when available, or the use of basic dosimetry principles for broad classes of materials. Accurate dose estimation is essential not only for dose-response assessment, but also for interspecies extrapolation and for risk characterization at given exposures. Inhalation dosimetry is the focus of this paper since it is a major route of exposure in the workplace. Practical examples of dose estimation and OEL derivation are provided for inhaled gases and particulates.
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Affiliation(s)
- Eileen D. Kuempel
- National Institute for Occupational Safety and Health, Education and Information Division, Cincinnati, Ohio
| | - Lisa M. Sweeney
- Henry M. Jackson Foundation for the Advancement of Military Medicine, Naval Medical Research Unit Dayton, Wright-Patterson Air Force Base, Ohio
| | - John B. Morris
- School of Pharmacy, University of Connecticut, Storrs, Connecticut
| | - Annie M. Jarabek
- U.S. Environmental Protection Agency, National Center for Environmental Assessment, Research Triangle Park, North Carolina
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15
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Dotson GS, Maier A, Siegel PD, Anderson SE, Green BJ, Stefaniak AB, Codispoti CD, Kimber I. Setting Occupational Exposure Limits for Chemical Allergens--Understanding the Challenges. JOURNAL OF OCCUPATIONAL AND ENVIRONMENTAL HYGIENE 2015; 12 Suppl 1:S82-98. [PMID: 26583909 PMCID: PMC4685595 DOI: 10.1080/15459624.2015.1072277] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Chemical allergens represent a significant health burden in the workplace. Exposures to such chemicals can cause the onset of a diverse group of adverse health effects triggered by immune-mediated responses. Common responses associated with workplace exposures to low molecular weight (LMW) chemical allergens range from allergic contact dermatitis to life-threatening cases of asthma. Establishing occupational exposure limits (OELs) for chemical allergens presents numerous difficulties for occupational hygiene professionals. Few OELs have been developed for LMW allergens because of the unique biological mechanisms that govern the immune-mediated responses. The purpose of this article is to explore the primary challenges confronting the establishment of OELs for LMW allergens. Specific topics include: (1) understanding the biology of LMW chemical allergies as it applies to setting OELs; (2) selecting the appropriate immune-mediated response (i.e., sensitization versus elicitation); (3) characterizing the dose (concentration)-response relationship of immune-mediated responses; (4) determining the impact of temporal exposure patterns (i.e., cumulative versus acute exposures); and (5) understanding the role of individual susceptibility and exposure route. Additional information is presented on the importance of using alternative exposure recommendations and risk management practices, including medical surveillance, to aid in protecting workers from exposures to LMW allergens when OELs cannot be established.
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Affiliation(s)
- G. S. Dotson
- Education and Information Division, Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health, Cincinnati, Ohio
- Address correspondence to G.S. Dotson, Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health, Education and Information Division, 1090 Tusculum Avenue, MS C-32, CincinnatiOhio45226. E-mail:
| | - A. Maier
- Education and Information Division, Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health, Cincinnati, Ohio
- College of Medicine, University of Cincinnati, Cincinnati, Ohio
| | - P. D. Siegel
- Health Effects Laboratory Division, Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health, Morgantown, West Virginia
| | - S. E. Anderson
- Health Effects Laboratory Division, Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health, Morgantown, West Virginia
| | - B. J. Green
- Health Effects Laboratory Division, Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health, Morgantown, West Virginia
| | - A. B. Stefaniak
- Respiratory Health Division, Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health, Morgantown, West Virginia
| | - C. D. Codispoti
- Department of Immunology and Microbiology, Rush University Medical Center, Chicago, Illinois
| | - I. Kimber
- Faculty of Life Sciences, University of Manchester, Manchester, United Kingdom
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Deveau M, Chen CP, Johanson G, Krewski D, Maier A, Niven KJ, Ripple S, Schulte PA, Silk J, Urbanus JH, Zalk DM, Niemeier RW. The Global Landscape of Occupational Exposure Limits--Implementation of Harmonization Principles to Guide Limit Selection. JOURNAL OF OCCUPATIONAL AND ENVIRONMENTAL HYGIENE 2015; 12 Suppl 1:S127-44. [PMID: 26099071 PMCID: PMC4654639 DOI: 10.1080/15459624.2015.1060327] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Occupational exposure limits (OELs) serve as health-based benchmarks against which measured or estimated workplace exposures can be compared. In the years since the introduction of OELs to public health practice, both developed and developing countries have established processes for deriving, setting, and using OELs to protect workers exposed to hazardous chemicals. These processes vary widely, however, and have thus resulted in a confusing international landscape for identifying and applying such limits in workplaces. The occupational hygienist will encounter significant overlap in coverage among organizations for many chemicals, while other important chemicals have OELs developed by few, if any, organizations. Where multiple organizations have published an OEL, the derived value often varies considerably-reflecting differences in both risk policy and risk assessment methodology as well as access to available pertinent data. This article explores the underlying reasons for variability in OELs, and recommends the harmonization of risk-based methods used by OEL-deriving organizations. A framework is also proposed for the identification and systematic evaluation of OEL resources, which occupational hygienists can use to support risk characterization and risk management decisions in situations where multiple potentially relevant OELs exist.
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Affiliation(s)
- M. Deveau
- McLaughlin Centre for Population Health Risk Assessment, University of Ottawa, Ottawa, Ontario, Canada
- Faculty of Graduate and Postdoctoral Studies, University of Ottawa, Ottawa, Ontario, Canada
- Address correspondence to M. Deveau, McLaughlin Centre for Population Health Risk Assessment, University of Ottawa, Ottawa, Ontario, K1N 6N5, Canada. E-mail:
| | - C-P Chen
- Department of Occupational Safety and Health, College of Public Health, China Medical University, Taichung, Taiwan
| | - G. Johanson
- Work Environment Toxicology, Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden
| | - D. Krewski
- McLaughlin Centre for Population Health Risk Assessment, University of Ottawa, Ottawa, Ontario, Canada
| | - A. Maier
- Department of Environmental Health, College of Medicine, University of Cincinnati, Cincinnati, Ohio
| | - K. J. Niven
- Shell Health, Shell International B.V., The Hague, The Netherlands
| | - S. Ripple
- Global Industrial Hygiene Expertise Center, The Dow Chemical Company, Midland, Michigan
| | - P. A. Schulte
- Education and Information Division, National Institute for Occupational Safety and Health, Cincinnati, Ohio
| | - J. Silk
- Directorate of Standards and Guidance, Occupational Safety and Health Administration, Washington, DC (Retired)
| | - J. H. Urbanus
- Shell Health, Shell International B.V., The Hague, The Netherlands
| | - D. M. Zalk
- ES&H Directorate, Lawrence Livermore National Laboratory, Livermore, California
| | - R. W. Niemeier
- Education and Information Division, National Institute for Occupational Safety and Health, Cincinnati, Ohio
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