Last data update: Jun 03, 2024. (Total: 46935 publications since 2009)
Records 1-17 (of 17 Records) |
Query Trace: Lentz T [original query] |
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Banding together: making the case for occupational exposure bands
Lentz TJ , Edmondson M . Synergist 2022 33 (5) 38-41 Occupational hygienists and safety and health practitioners have a solid history involving the use of occupational exposure limits (OELs). The role of OELs in characterizing workplace exposures to potentially hazardous chemicals has been significant, and they also help to ensure appropriate protections are in place and functioning. In addition, OELs provide the means for hazard assessment and risk communication. Yet setting appropriate OELs is resource intensive, requiring dose-response data, exposure data, and technical expertise to accurately characterize hazards for risk management purposes. And in a world of work where the number of chemical substances in use vastly exceeds the number of chemicals with OELs, the search for additional strategies for chemical risk assessment and management began. One such strategy gaining stronger acceptance and increasing utility is occupational exposure banding and the use of occupational exposure bands (OEBs). |
A framework for integrating information resources for chemical emergency management and response
Seaton MG , Maier A , Sachdeva S , Barton C , Ngai E , Lentz TJ , Rane PD , McKernan LT . Am J Disaster Med 2019 14 (1) 33-49 Effective emergency management and response require appropriate utilization of various resources as an incident evolves. This manuscript describes the information resources used in chemical emergency management and operations and how their utility evolves from the initial response phase to recovery to event close out. The authors address chemical hazard guidance in the context of four different phases of emergency response: preparedness, emergency response (both initial and ongoing), recovery, and mitigation. Immediately following a chemical incident, during the initial response, responders often use readily available, broad-spectrum guidance to make rapid decisions in the face of uncertainties regarding potential exposure to physical and health hazards. Physical hazards are described as the hazards caused by chemicals that can cause harm with or without direct contact. Examples of physical hazards include explosives, flammables, and gases under pressure. This first line of resources may not be chemical-specific in nature, but it can provide guidance related to isolation distances, protective actions, and the most important physical and health threats. During the ongoing response phase, an array of resources can provide detailed information on physical and health hazards related to specific chemicals of concern. Consequently, risk management and mitigation actions evolve as well. When the incident stabilizes to a recovery phase, the types of information resources that facilitate safe and effective incident management evolve. Health and physical concerns transition from acute toxicity and immediate hazards to both immediate and latent health effects. Finally, the information inputs utilized during the preparedness phase include response evaluations of past events, emergency preparedness planning, and chemical-specific guidance about chemicals present. This manuscript details a framework for identifying the effective use of information resources at each phase and provides case study examples from chemical hazard emergencies. |
Application of the draft NIOSH Occupational Exposure Banding Process to Bisphenol A: A case study
Hines CJ , Lentz TJ , McKernan L , Rane P , Whittaker C . J Occup Environ Hyg 2018 16 (2) 1-20 Bisphenol A is a commercially important chemical used to make polycarbonate plastic, epoxy resins and other specialty products. Despite an extensive body of in vitro, animal and human observational studies on the effects of exposure to bisphenol A, no authoritative bodies in the U.S. have adopted or recommended occupational exposure limits for bisphenol A. In 2017, the National Institute for Occupational Safety and Health published a Draft process for assigning health-protective occupational exposure bands, i.e. an airborne concentration range, to chemicals lacking an occupational exposure limit. Occupational exposure banding is a systematic process that uses both quantitative and qualitative toxicity information on selected health effect endpoints to assign an occupational exposure band for a chemical. The Draft process proposes three methodological tiers of increasing complexity for assigning an occupational exposure band. We applied Tier 1 (based on the Globally Harmonized System of Classification and Labelling) and Tier 2 (based on authoritative sources/reviews) to assign an occupational exposure band to bisphenol A. Under both Tier 1 and 2, the occupational exposure band for bisphenol A was "E" (<0.01 mg/m(3)), an assignment based on eye damage. "E" is the lowest exposure concentration range, reserved for chemicals with high potential toxicity. If eye damage was excluded in assigning an air concentration exposure range, then bisphenol A would band as "D" (>0.01 to 0.1 mg/m(3)) under Tier 1 (based on reproductive toxicity and respiratory/skin sensitization) and under Tier 2 (based on specific target organ toxicity-repeated exposure). In summary, Tiers 1 and 2 gave the same occupational exposure band for bisphenol A when eye damage was included ("E") or excluded ("D") as an endpoint. |
The "bandits" speak: NIOSH considers feedback from users of its proposed occupational exposure banding process
McKernan LT , Lentz TJ . Synergist 2018 29 (5) 40-42 The rate at which chemicals are introduced into commerce continues to outpace the development of authoritative occupational exposure limits. Occupational exposure banding is a tool that empowers and enables occupational hygienists to address unregulated chemicals. An occupational exposure band is not meant to replace an OEL; rather, it serves as a starting point to inform risk management decisions. Given the utility of an OEB, more occupational hygiene professionals are embracing the proposed NIOSH occupational exposure banding tool and using the occupational exposure banding process to guide their risk management decisions for chemicals without OELs. Occupational exposure banding, also known as hazard banding, is a process intended to quickly and accurately assign chemicals to specific categories (bands) that correspond to a range of exposure concentrations. These bands are assigned on the basis of a chemical’s toxicological potency and the adverse health effects associated with exposure to the chemical. The output of this process is an OEB. The pharmaceutical sector and some major chemical companies have used occupational exposure banding over the past several decades to establish exposure control limits or ranges for new or existing chemicals that lack formal OELs. |
Limit of detection and threshold for positivity of the Centers for Disease Control and Prevention assay for factor VIII inhibitors
Miller CH , Boylan B , Shapiro AD , Lentz SR , Wicklund BM . J Thromb Haemost 2017 15 (10) 1971-1976 BACKGROUND: The Bethesda assay (BA) for measurement of factor VIII (FVIII) inhibitors called for quantitation of positive inhibitors using dilutions producing 25-75% residual activity (RA), corresponding to 0.4-2.0 Bethesda units, recommending use of "more sensitive methods" for samples with RA closer to 100%. The Nijmegen modification (NBA) changed the reagents used but not these calculations. Some specimens negative by NBA have been shown to have FVIII antibodies detectable by sensitive immunologic methods. OBJECTIVE: To examine the performance at very low inhibitor titers of the Centers for Disease Control and Prevention (CDC)-modified NBA (CDC-NBA), which includes preanalytical heat inactivation to liberate bound anti-FVIII antibodies. METHODS: Specimens with known inhibitors were tested by CDC-NBA. IgG4 anti-FVIII antibodies were measured by fluorescence immunoassay (FLI). RESULTS: Diluted inhibitors showed linearity below 0.4 Nijmegen-Bethesda units (NBU). Using 4 statistical methods, the limit of detection of the CDC-NBA was determined to be 0.2 NBU. IgG4 anti-FVIII antibodies, which correlate most strongly with functional inhibitors, were present at rates above the background rate of healthy controls in specimens with titers ≥0.2 NBU and showed an increase in frequency from 14.3% at 0.4 NBU to 67% at the established threshold for positivity of 0.5 NBU. CONCLUSIONS: The CDC-NBA can detect inhibitors down to 0.2 NBU. The FLI, which is more sensitive, demonstrates anti-FVIII IgG4 in some patients with negative (<0.5) NBU. The sharp increase in IgG4 frequency between 0.4-0.5 NBU validates the established threshold for positivity of ≥0.5 NBU for the CDC-NBA, supporting the need for method-specific thresholds This article is protected by copyright. All rights reserved. |
Use of the "exposome" in the practice of epidemiology: A primer on -omic technologies
DeBord DG , Carreon T , Lentz TJ , Middendorf PJ , Hoover MD , Schulte PA . Am J Epidemiol 2016 184 (4) 302-14 The exposome has been defined as the totality of exposures individuals experience over the course of their lives and how those exposures affect health. Three domains of the exposome have been identified: internal, specific external, and general external. Internal factors are those that are unique to the individual, and specific external factors include occupational exposures and lifestyle factors. The general external domain includes sociodemographic factors such as educational level and financial status. Eliciting information on the exposome is daunting and not feasible at present; the undertaking may never be fully realized. A variety of tools have been identified to measure the exposome. Biomarker measurements will be one of the major tools in exposomic studies. However, exposure data can also be obtained from other sources such as sensors, geographic information systems, and conventional tools such as survey instruments. Proof-of-concept studies are being conducted that show the promise of exposomic investigation and the integration of different kinds of data. The inherent value of exposomic data in epidemiologic studies is that they can provide greater understanding of the relationships among a broad range of chemical and other risk factors and health conditions and ultimately lead to more effective and efficient disease prevention and control. |
State-of-the-science: the evolution of occupational exposure limit derivation and application
Maier A , Lentz TJ , MacMahon KL , McKernan LT , Whittaker C , Schulte PA . J Occup Environ Hyg 2015 12 Suppl 1 S4-6 Occupational exposure limits (OELs) are a critical component of the risk assessment and risk management process and their use remains a staple of occupational hygiene practice. There are dozens of organizations and agencies that derive OELs worldwide. Yet, while most of these groups describe their administrative procedures as well as the rationale for the derivation of OELs for individual substances, few provide equally complete documentation of the underlying scientific methodology for conducting the quantitative risk assessment employed in OEL development. The paucity of written descriptions of OEL development methodology has resulted in a lack of transparency related to implementation of important scientific principles for OEL development and inconsistent practices for OEL development within and among organizations. The absence of such transparency limits the opportunities for international harmonization of existing values and OEL setting practices among organizations. | Given these and other challenges, the National Institute for Occupational Safety and Health (NIOSH) began an effort to identify and characterize leading issues pertaining to OELs and their development through research which culminated in a collection of articles focused on each key issue. Those articles and the key issues they explore comprise this supplement of the Journal of Occupational and Environmental Hygiene. Utilizing subject matter expertise from researchers and thought leaders in the occupational hygiene profession and affiliated fields of environmental public health, the goal of this effort is to describe the issues related to education and communication of science principles and to understand how they can be incorporated into (and thereby impact) the practices of OEL development and interpretation. Focusing specifically on the state-of-the-science in the fields of exposure science, occupational hygiene, risk assessment, and toxicology this effort sought to provide a clear description of how advances in these research areas can contribute to the practice of OEL setting—by reviewing the methods used for most OELs that are currently available as well as new methods that are actively being incorporated in the OEL process. An essential topic included within the set of complementary and interrelated articles dedicated to this pursuit is the consideration and interpretation of OELs in the context of evolving risk management practices. The articles are intended to serve as a current critical review of occupational risk assessment methods that will enable occupational hygiene professionals to have a clear understanding of the science methods incorporated in the OELs they develop or use. A brief introduction to each article in this collection is provided in the following paragraphs. |
Aggregate exposure and cumulative risk assessment-integrating occupational and non-occupational risk factors
Lentz TJ , Dotson GS , Williams PR , Maier A , Gadagbui B , Pandalai SP , Lamba A , Hearl F , Mumtaz M . J Occup Environ Hyg 2015 12 Suppl 1 S112-26 Occupational exposure limits have traditionally focused on preventing morbidity and mortality arising from inhalation exposures to individual chemical stressors in the workplace. While central to occupational risk assessment, occupational exposure limits have limited application as a refined disease prevention tool because they do not account for all of the complexities of the work and non-occupational environments and are based on varying health endpoints. To be of greater utility, occupational exposure limits and other risk management tools could integrate broader consideration of risks from multiple exposure pathways and routes (aggregate risk) as well as the combined risk from exposure to both chemical and non-chemical stressors, within and beyond the workplace, including the possibility that such exposures may cause interactions or modify the toxic effects observed (cumulative risk). Although still at a rudimentary stage in many cases, a variety of methods and tools have been developed or are being used in allied risk assessment fields to incorporate such considerations in the risk assessment process. These approaches, which are collectively referred to as cumulative risk assessment, have potential to be adapted or modified for occupational scenarios and provide a tangible path forward for occupational risk assessment. Accounting for complex exposures in the workplace and the broader risks faced by the individual also requires a more complete consideration of the composite effects of occupational and non-occupational risk factors to fully assess and manage worker health problems. Barriers to integrating these different factors remain, but new and ongoing community-based and worker health-related initiatives may provide mechanisms for identifying and integrating risk from aggregate exposures and cumulative risks from all relevant sources, be they occupational or non-occupational. |
Concordance between molecular and phenotypic testing of Mycobacterium tuberculosis complex isolates for resistance to rifampin and isoniazid in the United States.
Yakrus MA , Driscoll J , Lentz AJ , Sikes D , Hartline D , Metchock B , Starks AM . J Clin Microbiol 2014 52 (6) 1932-7 Multidrug-resistant (MDR) isolates of Mycobacterium tuberculosis complex (MTBC) are defined by resistance to at least rifampin (RMP) and isoniazid (INH). Rapid and accurate detection of multidrug resistance is essential for effective treatment and interruption of disease transmission of tuberculosis (TB). Over-diagnosis of MDR TB may result in treatment with second-line drugs that are more costly, less effective, and more poorly tolerated than first-line drugs. CDC offers rapid confirmation of MDR TB by molecular detection of mutations associated with resistance (MDDR) to RMP and INH along with analysis for resistance to other first-line and second-line drugs. Simultaneously, CDC does growth-based phenotypic drug susceptibility testing (DST) by the indirect agar proportion method for a panel of first-line and second-line antituberculous drugs. We reviewed discordance between molecular and phenotypic DST for INH and RMP for 285 isolates submitted as MTBC to CDC September 2009-February 2011. We compared CDC's results with those from the submitting public health laboratories (PHL). Concordance between molecular and phenotypic testing at CDC was 97.4% for RMP and 92.5% for INH resistance. Concordance between CDC's molecular testing and PHL DST results was 93.9% for RMP and 90.0% for INH. Overall concordance between CDC molecular and PHL DST results was 91.7% for RMP and INH collectively. Discordance was primarily attributable to absence of known INH-resistance mutations in isolates INH resistant by DST and detection of mutations associated with low-level RMP resistance in isolates that were RMP susceptible by phenotypic DST. Both molecular and phenotypic test results should be considered for diagnosis of MDR TB. |
Occupational safety and health, green chemistry, and sustainability: a review of areas of convergence
Schulte PA , McKernan LT , Heidel DS , Okun AH , Dotson GS , Lentz TJ , Geraci CL , Heckel PE , Branche CM . Environ Health 2013 12 31 With increasing numbers and quantities of chemicals in commerce and use, scientific attention continues to focus on the environmental and public health consequences of chemical production processes and exposures. Concerns about environmental stewardship have been gaining broader traction through emphases on sustainability and "green chemistry" principles. Occupational safety and health has not been fully promoted as a component of environmental sustainability. However, there is a natural convergence of green chemistry/sustainability and occupational safety and health efforts. Addressing both together can have a synergistic effect. Failure to promote this convergence could lead to increasing worker hazards and lack of support for sustainability efforts. The National Institute for Occupational Safety and Health has made a concerted effort involving multiple stakeholders to anticipate and identify potential hazards associated with sustainable practices and green jobs for workers. Examples of potential hazards are presented in case studies with suggested solutions such as implementing the hierarchy of controls and prevention through design principles in green chemistry and green building practices. Practical considerations and strategies for green chemistry, and environmental stewardship could benefit from the incorporation of occupational safety and health concepts which in turn protect affected workers. |
Comparison of clot-based, chromogenic, and fluorescence assays for measurement of factor VIII inhibitors in the U.S. Hemophilia Inhibitor Research Study
Miller CH , Rice AS , Boylan B , Shapiro AD , Lentz SR , Wicklund BM , Kelly FM , Soucie JM . J Thromb Haemost 2013 11 (7) 1300-9 BACKGROUND: Detection and validation of inhibitors (antibodies) to hemophilia treatment products are important for clinical care, evaluation of product safety, and assessment of population trends. METHODS: Centralized monitoring for factor VIII (FVIII) inhibitors was conducted for patients in the Hemophilia Inhibitor Research Study using a previously reported modified Nijmegen-Bethesda clotting assay (NBA), a chromogenic Bethesda assay (CBA), and a novel fluorescence immunoassay (FLI). RESULTS: NBA and CBA were performed on 1005 specimens and FLI on 272 specimens. CBA was negative on 880/883 specimens (99.7%) with Nijmegen-Bethesda units (NBU)<0.5 and positive on 42/42 specimens (100%) with NBU≥2.0 and 43/80 specimens (53.8%) with NBU 0.5-1.9. Among specimens with positive NBA and negative CBA, 58.1% were FLI-negative, 12.9% had evidence of lupus anticoagulant, and 35.5% had non-time-dependent inhibition. CBA and FLI were positive on 72.4% and 100% of 1.0-1.9 NBU specimens and 43.1% and 50.0% of 0.5-0.9 NBU specimens. FLI detected antibodies in 98.0% of CBA-positive and 81.6% of NBA-positive specimens (P=0.004). Among 21 new inhibitors detected by NBA, 5 (23.8%) with 0.7-1.3 NBU did not react in CBA or FLI. Among previously positive patients with 0.5-1.9 NBU, 7/25 (28%) were not CBA or FLI positive. FLI was positive on 36/169 NBU-negative specimens (21.3%). CONCLUSIONS: FVIII specificity could not be demonstrated by CBA or FLI for 26% of inhibitors of 0.5-1.9 NBU; such results must be interpreted with caution. Low titer inhibitors detected in clot-based assays should always be repeated, with consideration given to evaluating their reactivity with FVIII using more specific assays. (This article is protected by copyright. All rights reserved.) |
Expanding control banding for workplace silica exposures throughout the Americas
Beaucham CC , Lentz TJ , Rice FL . Int J Occup Environ Health 2012 18 (4) 344-347 BACKGROUND: Silicosis, a lung disease caused by inhaling respirable crystalline silica dust, is an occupational illness affecting millions of workers worldwide. The National Institute for Occupational Safety and Health (NIOSH) has partnered with the World Health Organization, the International Labour Organization, and multiple agencies in the Americas to implement the program "The Elimination of Silicosis in the Americas". OBJECTIVES: One component of this program is control banding, a qualitative risk assessment and management strategy that allows non-experts to use task-based hazard data and potential exposure information to determine appropriate controls. RESULTS: From 2005 to the present, NIOSH occupational health researchers have worked with experts in Chile, Peru, Colombia, and Brazil to assess, implement, and provide tools to evaluate the use of control banding methodology. |
Checklist model to improve work practices in small-scale demolition operations with silica dust exposures
Muianga C , Rice C , Lentz T , Lockey J , Niemeier R , Succop P . Int J Environ Res Public Health 2012 9 (2) 343-361 A systematic approach was developed to review, revise and adapt existing exposure control guidance used in developed countries for use in developing countries. One-page employee and multiple-page supervisor guidance sheets were adapted from existing documents using a logic framework and workers were trained to use the information to improve work practices. Interactive, hands-on training was delivered to 26 workers at five small-scale demolition projects in Maputo City, Mozambique, and evaluated. A pre-and-post walkthrough survey used by trained observers documented work practice changes. Worker feedback indicated that the training was effective and useful. Workers acquired knowledge (84% increase, p < 0.01) and applied the work practice guidance. The difference of proportions between use of work practice components before and after the intervention was statistically significant (p < 0.05). Changes in work practices following training included preplanning, use of wet methods and natural ventilation and end-of-task review. Respirable dust measurements indicated a reduction in exposure following training. Consistency in observer ratings and observations support the reliability and validity of the instruments. This approach demonstrated the short-term benefit of training in changing work practices; follow-up is required to determine the long-term impact on changes in work practices, and to evaluate the need for refresher training. |
The evolution of skin notations for occupational risk assessment: a new NIOSH strategy
Dotson GS , Chen CP , Gadagbui B , Maier A , Ahlers HW , Lentz TJ . Regul Toxicol Pharmacol 2011 61 (1) 53-62 This article presents an overview of a strategy for assignment of hazard-specific skin notations (SK), developed by the National Institute for Occupational Safety and Health (NIOSH). This health hazard characterization strategy relies on multiple SKs capable of delineating systemic (SYS), direct (DIR), and immune-mediated (SEN) adverse effects caused by dermal exposures to chemicals. One advantage of the NIOSH strategy is the ability to combine SKs when it is determined that a chemical may cause multiple adverse effects following dermal contact (e.g., SK: SYS-DIR-SEN). Assignment of the SKs is based on a weight-of-evidence (WOE) approach, which refers to the critical examination of all available data from diverse lines of evidence and the derivation of a scientific interpretation based on the collective body of data including its relevance, quality, and reported results. Numeric cutoff values, based on indices of toxic potency, serve as guidelines to aid in consistently determining a chemical's relative toxicity and hazard potential. The NIOSH strategy documents the scientific rationale for determination of the hazard potential of a chemical and the subsequent assignment of SKs. A case study of acrylamide is presented as an application of the NIOSH strategy. |
High redundancy draft sequencing of 15 clinical and environmental Burkholderia strains
Mukhopadhyay S , Thomason MP , Lentz S , Nolan N , Willner K , Gee JE , Glass MB , Inglis TJ , Merritt A , Levy A , Sozhamannan S , Mateczun A , Read TD . J Bacteriol 2010 192 (23) 6313-4 The Gram negative Burkholderia genus includes several species of intracellular bacterial pathogens that pose substantial risk to humans. In this study we have generated draft genome sequences of 15 strains of B. oklahomensis, B. pseudomallei, B. thailandensis and B. ubonensis to an average sequence read coverage of 25-40 fold. |
Safety tips for roadway work zones
Mulhern B , Lentz TJ . Occup Health Saf 2010 79 (1) 18-20 June 3, 2008, turned into a nightmare for Chris and Janet Augeri. Instead of celebrating their son Rob's 31st birthday, they were making plans for his funeral. | Robert (Rob) Augeri of Londonderry, N.H., a husband and father of four children ranging in age from 1 to 12, was killed at 1:30 a.m. while working in a highway construction zone. Rob was painting lines in the roadway on Interstate 495 near Methuen, Mass., when a dump truck backed into him in the closed left travel lane. Neither the driver of the truck nor his passenger was injured. |
Don't become a statistic: work safely at heights
Mulhern B , Lentz TJ . Occup Health Saf 2009 78 (7) 36, 38, 40 passim In Alabama, a framing crew member who was moving a roof truss into place while supporting himself on an 8-inch wide structural beam fell 27 feet to the ground inside the partially constructed building. The native Mexican laborer, who understood little English, was not wearing or using personal fall protection equipment. An 8-foot by 4-foot truss fell at the same time, striking the worker's head when he hit the ground. He was pronounced dead at a local hospital. |
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