2022 National Occupational Injury Research Symposium (NOIRS): Preventing workplace injuries in a changing world

About NOIRS: The National Occupational Injury Research Symposium (NOIRS) is the only conference solely dedicated to occupational injury research and prevention. The 8th NOIRS, sponsored by the National Institute for Occupational Safety and Health (NIOSH) and several partners, was held on May 10-12, 2022. NOIRS was held entirely virtually in response to concerns of the COVID-19 pandemic and honoring the symposium theme "Preventing Workplace Injuries in a Changing World." About this Special Issue: The intent of this issue is to highlight the breadth of high-quality presentations at NOIRS, and to make them available to those who did not participate in the conference. This issue includes three short communication articles and nine research articles. Featured research articles in this special issue span a wide variety of methods, data sources, and worker populations. They address leading and emerging causes and contributors to occupational injury in a range of industries and occupations. Concluding Remarks: We hope that this special issue provides readers with a view into some of the research presented at the 2022 NOIRS. We also hope the articles are useful for research and practice, and thinking toward the future.

Analysis of single nucleotide polymorphisms in chronic beryllium disease

Sarcoidosis and chronic beryllium disease (CBD) are phenocopies, however the latter one has a clear trigger factor that is beryllium exposure. This study analyses single nucleotide polymorphisms (SNPs) in a large cohort for beryllium-exposed persons. SNPs were chosen for their relevance in sarcoidosis. Even though one of largest cohorts of beryllium-exposed persons was analysed, no statistically relevant association between any SNP and CBD could be verified. Notably, some SNPs exhibit inverse OR for beryllium sensitization and CBD with nominally statistical significance, which allows hypothesizing about pathophysiological role of genes for the disease triggering and development.

2018 National Occupational Injury Research Symposium: Advancing worker safety in the 21st century through research and practice

ABOUT NOIRS 2018

The National Occupational Injury Research Symposium (NOIRS) is the only regularly held research forum in the United States dedicated to occupational injury research and prevention. The 7^th NOIRS, sponsored by the National Institute for Occupational Safety and Health (NIOSH) and several partners, was held October 16–18, 2018 in Morgantown, West Virginia. The symposium theme was “Advancing Worker Safety in the 21^st Century through Research and Practice.”

ARTICLE SELECTION

This special issue of the Journal of Safety Research highlights exemplary research presented at the symposium, making it available to those who did not attend. The articles included in this issue address leading causes of occupational injury, cross-cutting issues such as organization-based prevention, and emerging issues associated with advancements in technology. The articles draw from public health, the social sciences, and engineering disciplines.

CONCLUDING REMARKS

Research presented at NOIRS over the years has expanded beyond describing occupational injuries and developing and evaluating intervention approaches, to studying how to ensure that research is put into practice. While there has been progress in advancing the prevention of occupational injuries, there is more to be done, and attention is needed to projected transformations in workplaces, work and the workforce. NIOSH looks forward to working with partners to co-sponsor the 8^th NOIRS, tentatively planned for the fall of 2021, to present state-of-the art research to advance worker safety.

Associations of Metrics of Peak Inhalation Exposure and Skin Exposure Indices With Beryllium Sensitization at a Beryllium Manufacturing Facility

OBJECTIVES

Peak beryllium inhalation exposures and exposure to the skin may be relevant for developing beryllium sensitization (BeS). The objective of this study was to identify risk factors associated with BeS to inform the prevention of sensitization, and the development of chronic beryllium disease (CBD).

METHODS

In a survey of short-term workers employed at a primary beryllium manufacturing facility between the years 1994-1999, 264 participants completed a questionnaire and were tested for BeS. A range of qualitative and quantitative peak inhalation metrics and skin exposure indices were created using: personal full-shift beryllium exposure measurements, 15 min to 24 h process-specific task and area exposure measurements, glove measurements as indicator of skin exposure, process-upset information gleaned from historical reports, and self-reported information on exposure events. Hierarchical clustering was conducted to systematically group participants based on similarity of patterns of 16 exposure variables. The associations of the exposure metrics with BeS and self-reported skin symptoms (in work areas processing beryllium salts as well as in other work areas) were evaluated using correlation analysis, log-binomial and logistic regression models with splines.

RESULTS

Metrics of peak inhalation exposure, indices of skin exposure, and using material containing beryllium salts were significantly associated with skin symptoms and BeS; skin symptoms were a strong predictor of BeS. However, in this cohort, we could not tease apart the independent effects of skin exposure from inhalation exposure, as these exposures occurred simultaneously and were highly correlated. Hierarchical clustering identified groups of participants with unique patterns of exposure characteristics resulting in different prevalence of BeS and skin symptoms. A cluster with high skin exposure index and use of material containing beryllium salts had the highest prevalence of BeS and self-reported skin symptoms, followed by a cluster with high inhalation and skin exposure index and a very small fraction of jobs in which beryllium salts were used. A cluster with low inhalation and skin exposure and no workers using beryllium salts had no cases of BeS.

CONCLUSION

Multiple pathways and types of exposure were associated with BeS and may be important for informing BeS prevention. Prevention efforts should focus on controlling airborne beryllium exposures with attention to peaks, use of process characteristics (e.g. the likelihood of upset conditions to design interventions) minimize skin exposure to beryllium particles, and in particular, eliminate skin contact with beryllium salts to interrupt potential exposure pathways for BeS risk.

A post-conference evaluation of the 2015 National Occupational Injury Research Symposium

INTRODUCTION

The National Occupational Injury Research Symposium (NOIRS) is the only national forum focused on occupational injury research findings, data and methods, and prevention strategies; it has been convened every 3-5years since 1997. Held in May 2015, the 6th symposium's theme was "Advancing Occupational Injury Research through Integration and Partnership." Organizers requested that attendees complete a post-meeting evaluation to assess meeting impact, and gather information useful in planning subsequent meetings and activities.

METHOD

The questionnaire was publicized via a quick response code and link to the survey on symposium book cover, and mentioned at each scientific session. The online survey was designed to be completed in ≤15min; no identifying information was collected. Survey link remained open for seven days post-symposium.

RESULTS

About 50% of registered attendees responded. Almost half were attending their first NOIRS. Most were researchers (69%); 45% were affiliated with government and 38% with university or research institute. Five of six reported that the symposium mostly or completely met expectations. Reasons for attending included gaining exposure to new areas of research (87%), sharing their research (80%), and to develop new ideas for conducting research (79%). The majority (90%) reported that the symposium provided adequate networking opportunities. The conference venue was reported as good or better by 69%, moreso among repeat attendees (77%) compared to first-timers (61%).

DISCUSSION

The evaluation demonstrated that NOIRS was valuable to attendees, and provided a forum for sharing research results, developing new research ideas, and networking. Respondents provided input on different aspects of NOIRS and suggestions useful in planning next NOIRS, tentatively scheduled for 2018. NOIRS 2015 objectives for integration across disciplines and partnership with industry and safety professionals were partially met. In planning NOIRS 2018, more attention should be paid to attracting and engaging a broader spectrum of attendees.

6th National Occupational Injury Research Symposium: Advancing Occupational Injury Research Through Integration and Partnership

INTRODUCTION

The National Occupational Injury Research Symposium (NOIRS) is the only regularly held forum exclusively dedicated to occupational injury research and prevention.

METHOD

The 2015 conference theme, advancing occupational injury research through integration and partnership, shaped the conference and is reflected in articles selected for this special issue.

RESULTS' CONCLUSION

The 6th NOIRS, held May 19-21, 2015, brought together more than 250 researchers, occupational safety practitioners and students to share and discuss occupational injury research. Articles in this special issue highlight some of the research presented at the conference, reflect multiple scientific disciplines and approaches, cover a breadth of occupational injury causes and worker populations, and provide examples of research advanced by partnerships.

PRACTICAL APPLICATIONS

The next NOIRS, tentatively scheduled for 2018, will build upon the theme of integration and partnership as well as feedback from conference attendees.

Work-related asthma cluster at a syntactic foam manufacturing facility - Massachusetts 2008-2013

Work-related asthma is asthma that is caused or exacerbated by exposure to specific substances in the workplace. Approximately 10%-16% of adult-onset asthma cases are attributable to occupational factors, and estimates of asthma exacerbated by work range from 13% to 58%. During 2008-2012, the Massachusetts Department of Public Health received nine reports of work-related asthma among workers at a facility that manufactured syntactic foam used for flotation in the offshore oil and gas industry. These reports and a request from facility employees led to a CDC health hazard evaluation during 2012-2013 in which CDC reviewed records, toured the facility, and administered a questionnaire to current employees. Investigators found that workers' risk for asthma increased substantially after hire, possibly because of known asthma triggers (i.e., asthmagens) used in production. The company has since initiated efforts to reduce employee exposures to these substances. This cluster of work-related asthma was identified through CDC-funded, state-based surveillance and demonstrates complementary state and federal investigations.

An official American Thoracic Society statement: diagnosis and management of beryllium sensitivity and chronic beryllium disease

RATIONALE

Beryllium continues to have a wide range of industrial applications. Exposure to beryllium can lead to sensitization (BeS) and chronic beryllium disease (CBD).

OBJECTIVES

The purpose of this statement is to increase awareness and knowledge about beryllium exposure, BeS, and CBD.

METHODS

Evidence was identified by a search of MEDLINE. The committee then summarized the evidence, drew conclusions, and described their approach to diagnosis and management.

MAIN RESULTS

The beryllium lymphocyte proliferation test is the cornerstone of both medical surveillance and the diagnosis of BeS and CBD. A confirmed abnormal beryllium lymphocyte proliferation test without evidence of lung disease is diagnostic of BeS. BeS with evidence of a granulomatous inflammatory response in the lung is diagnostic of CBD. The determinants of progression from BeS to CBD are uncertain, but higher exposures and the presence of a genetic variant in the HLA-DP β chain appear to increase the risk. Periodic evaluation of affected individuals can detect disease progression (from BeS to CBD, or from mild CBD to more severe CBD). Corticosteroid therapy is typically administered when a patient with CBD exhibits evidence of significant lung function abnormality or decline.

CONCLUSIONS

Medical surveillance in workplaces that use beryllium-containing materials can identify individuals with BeS and at-risk groups of workers, which can help prioritize efforts to reduce inhalational and dermal exposures.

Migration of Beryllium via Multiple Exposure Pathways among Work Processes in Four Different Facilities

Inhalation of beryllium is associated with the development of sensitization; however, dermal exposure may also be important. The primary aim of this study was to elucidate relationships among exposure pathways in four different manufacturing and finishing facilities. Secondary aims were to identify jobs with increased levels of beryllium in air, on skin, and on surfaces; identify potential discrepancies in exposure pathways, and determine if these are related to jobs with previously identified risk. Beryllium was measured in air, on cotton gloves, and on work surfaces. Summary statistics were calculated and correlations among all three measurement types were examined at the facility and job level. Exposure ranking strategies were used to identify jobs with higher exposures. The highest air, glove, and surface measurements were observed in beryllium metal production and beryllium oxide ceramics manufacturing jobs that involved hot processes and handling powders. Two finishing and distribution facilities that handle solid alloy products had lower exposures than the primary production facilities, and there were differences observed among jobs. For all facilities combined, strong correlations were found between air-surface (rp ≥ 0.77), glove-surface (rp ≥ 0.76), and air-glove measurements (rp ≥ 0.69). In jobs where higher risk of beryllium sensitization or disease has been reported, exposure levels for all three measurement types were higher than in jobs with lower risk, though they were not the highest. Some jobs with low air concentrations had higher levels of beryllium on glove and surface wipe samples, suggesting a need to further evaluate the causes of the discrepant levels. Although such correlations provide insight on where beryllium is located throughout the workplace, they cannot identify the direction of the pathways between air, surface, or skin. Ranking strategies helped to identify jobs with the highest combined air, glove, and/or surface exposures. All previously identified high-risk jobs had high air concentrations, dermal mass loading, or both, and none had low dermal and air. We have found that both pathways are relevant. [Supplementary materials are available for this article. Go to the publisher's online edition of Journal of Occupational and Environmental Hygiene for the following free supplemental resource: a file describing the forms of beryllium materials encountered during production and characteristics of the aerosols by process areas.].

A decision process for determining whether to conduct responder health research following large disasters

Disasters often set the stage for scientific inquiry within the field of occupational safety and health. This is especially true when the long-term consequences of exposures associated with a particular disaster are unclear. However, a responder research study can be costly and difficult to design, and researchers must consider whether the proposed study will produce useful, reliable results and is a prudent public health investment. The decision process can be segregated into various components, including scientific rationale that should be formally recognized as critical to efficiently and effectively determine whether a research study is warranted. The scientific rationale includes certain controlling or "gatekeeper" factors that should be present to proceed with research.

Long-term efficacy of a program to prevent beryllium disease

BACKGROUND

In 2000, a manufacturer of beryllium materials and products introduced a comprehensive program to prevent beryllium sensitization and chronic beryllium disease (CBD). We assessed the program's efficacy in preventing sensitization 9 years after implementation.

METHODS

Current and former workers hired since program implementation completed questionnaires and provided blood samples for the beryllium lymphocyte proliferation test (BeLPT). Using these data, as well as company medical surveillance data, we estimated beryllium sensitization prevalence.

RESULTS

Cross-sectional prevalence of sensitization was 0.7% (2/298). Combining survey results with surveillance results, a total of seven were identified as sensitized (2.3%). Early Program workers were more likely to be sensitized than Late Program workers; one of the latter was newly identified. All sensitization was identified while participants were employed. One worker was diagnosed with CBD during employment.

CONCLUSIONS

The combination of increased respiratory and dermal protection, enclosure and improved ventilation of high-risk processes, dust migration control, improved housekeeping, and worker and management education showed utility in reducing sensitization in the program's first 9 years. The low rate (0.6%, 1/175) among Late Program workers suggests that continuing refinements have provided additional protection against sensitization compared to the program's early years.

Chronic beryllium disease, HLA-DPB1, and the DP peptide binding groove

Multiple epidemiologic studies demonstrate associations between chronic beryllium disease (CBD), beryllium sensitization (BeS), and HLA-DPB1 alleles with a glutamic acid residue at position 69 (E69). Results suggest that the less-frequent E69 variants (non-*0201/*0202 alleles) might be associated with greater risk of CBD. In this study, we sought to define specific E69-carrying alleles and their amino acid sequences in the DP peptide binding groove, as well as their relationship to CBD and BeS risk, using the largest case control study to date. We enrolled 502 BeS/CBD subjects and 653 beryllium-exposed controls from three beryllium industries who gave informed consent for participation. Non-Hispanic white cases and controls were frequency-matched by industry. HLA-DPB1 genotypes were determined using sequence-specific primer PCR. The E69 alleles were tested for association with disease individually and grouped by amino acid structure using logistic regression. The results show that CBD cases were more likely than controls to carry a non-*02 E69 allele than an *02 E69, with odds ratios (95% confidence interval) ranging from 3.1 (2.1-4.5) to 3.9 (2.6-5.9) (p < 0.0001). Polymorphic amino acids at positions 84 and 11 were associated with CBD: DD versus GG, 2.8 (1.8-4.6), p < 0.0001; GD versus GG, 2.1 (1.5-2.8), p < 0.0001; LL versus GG, 3.2 (1.8-5.6), p < 0.0001; GL versus GG, 2.8 (2.1-3.8), p < 0.0001. Similar results were found within the BeS group and CBD/BeS combined group. We conclude that the less frequent E69 alleles confer more risk for CBD than does *0201. Recent studies examining how the composition and structure of the binding pockets influence peptide binding in MHC genes, as well of studies showing the topology of the TCR to likely bind DPB1 preferentially, give plausible biological rationale for these findings.

Sensitization and chronic beryllium disease at a primary manufacturing facility, part 2: validation of historical exposures

OBJECTIVE

The aim of this study was to evaluate the validity of a job exposure matrix (JEM) constructed for the period 1994-1999. Historical exposure estimates (HEE) for the JEM were constructed for all job and year combinations by applying temporal factors reflecting annual change in area air measurements (1994-1998) to the personal baseline exposure estimates (BEE) collected in 1999. The JEM was generated for an epidemiologic study to examine quantitative exposure-response relationships with sensitization and chronic beryllium disease.

METHODS

The validity of the BEE and HEE was evaluated by comparing them with a validation dataset of independently collected personal beryllium exposure measurements from 1999 and 1994-1998, respectively. Agreement between the JEM and validation data was assessed using relative bias and concordance correlation coefficients (CCC).

RESULTS

The BEE and HEE overestimated the measured exposures in their respective validation datasets by 8% and 6%, respectively. The CCC reflecting the deviation of the fitted line from the concordance line, showed good agreement for both BEE (CCC=0.80) and HEE (CCC=0.72). Proportional difference did not change with exposure levels or by process area and year. Overall, the agreement between the JEM and validation estimates (from combined HEE and BEE) was high (CCC=0.77).

CONCLUSIONS

This study demonstrated that the reconstructed beryllium exposures at a manufacturing facility were reliable and can be used in epidemiologic studies.

Efficacy of a program to prevent beryllium sensitization among new employees at a copper-beryllium alloy processing facility

OBJECTIVES

In 2000, 7% of workers at a copper-beryllium facility were beryllium sensitized. Risk was associated with work near a wire annealing/pickling process. The facility then implemented a preventive program including particle migration control, respiratory and dermal protection, and process enclosure. We assessed the program's efficacy in preventing beryllium sensitization.

METHODS

In 2000, the facility began testing new hires (program workers) with beryllium lymphocyte proliferation tests (BeLPTs) at hire and at intervals during employment. We compared sensitization incidence rates (IRs) and prevalence rates for workers hired before the program (legacy workers) with rates for program workers, including program worker subgroups. We also examined trends in BeLPTs from a single laboratory.

RESULTS

In all, five of 43 legacy workers (IR = 3.8/1,000 person-months) and three of 82 program workers (IR = 1.9/1,000 person-months) were beryllium sensitized, for an incidence rate ratio (IRR) of 2.0 (95% confidence interval [CI] 0.5, 10.1). Two of 37 pre-enclosure program workers (IR = 2.4/1,000 person-months) and one of 45 post-enclosure program workers (IR = 1.4/1,000 person-months) were beryllium sensitized, for IRRs of 1.6 (95% CI 0.3, 11.9) and 2.8 (95% CI 0.4, 66.2), respectively, compared with legacy workers. Test for trend in prevalence rates was significant. Among 2,159 first-draw BeLPTs during 95 months, we identified seven months when high numbers of redraws were required, with one possible misclassification in this facility.

CONCLUSIONS

Fewer workers became sensitized after implementation of the preventive program. However, low statistical power due to the facility's small workforce prevents a definitive conclusion about the program's efficacy. These findings have implications for other copper-beryllium facilities, where program components may merit application.

Impact of negatively charged patches on the surface of MHC class II antigen-presenting proteins on risk of chronic beryllium disease

Chronic beryllium disease (CBD) is a granulomatous lung disease that occurs primarily in workers who are exposed to beryllium dust or fumes. Although exposure to beryllium is a necessary factor in the pathobiology of CBD, alleles that code for a glutamic acid residue at the 69th position of the HLA-DPbeta1 gene have previously been found to be associated with CBD. To date, 43 HLA-DPbeta1 alleles that code for glutamic acid 69 (E69) have been described. Whether all of these E69 coding alleles convey equal risk of CBD is unknown. The present study demonstrates that, on the one hand, E69 alleloforms of major histocompatibility complex class II antigen-presenting proteins with the greatest negative surface charge convey the highest risk of CBD, and on the other hand, irrespective of allele, they convey equal risk of beryllium sensitization (BeS). In addition, the data suggest that the same alleles that cause the greatest risk of CBD are also important for the progression from BeS to CBD. Alleles convey the highest risk code for E26 in a constant region and for E69, aspartic acid 55 (D55), E56, D84 and E85 in hypervariable regions of the HLA-DPbeta1 chain. Together with the calculated high binding affinities for beryllium, these results suggest that an adverse immune response, leading to CBD, is triggered by chemically specific metal-protein interactions.

TNF-alpha polymorphisms in chronic beryllium disease and beryllium sensitization

OBJECTIVE

Tumor necrosis factor-alpha (TNF-alpha) is a potent cytokine involved in normal immune functions. The aim of this study was to investigate if there is an association between chronic beryllium disease or beryllium sensitization and two variants of the TNF-alpha gene located at -308 and -238 called TNF-alpha-308*02 and TNF-alpha-238*02.

METHODS

TNF-alpha-308 and TNF-alpha-238 genotyping was conducted in a large, population-based cohort consisting of 886 beryllium workers (92 individuals with chronic beryllium disease, 64 who were beryllium sensitized, and 730 individuals without sensitization or disease).

RESULTS

The odds of chronic beryllium disease in the presence of at least one TNF-alpha-308*02 or TNF-alpha-238*02 allele was not significant (OR=1.0; 95% CI=0.7, 1.7 and OR=0.8; 95% CI=0.4, 1.6). This was true regardless of whether a worker was homozygous or heterozygous for TNF-alpha-308*02 or TNF-alpha-238*02. Similarly, neither allele was associated with sensitization (P>0.05).

CONCLUSIONS

Unlike an earlier report, there was no association between these specific TNF-alpha alleles and either chronic beryllium disease or sensitization to beryllium.

Beryllium: A Modern Industrial Hazard

Beryllium exposure can cause a granulomatous lung disease in workers who develop a lymphocyte-mediated sensitization to the metal. Workers in diverse industries are at risk because beryllium's properties are critical to nuclear, aerospace, telecommunications, electronic, metal alloy, biomedical, and semiconductor industries. The occupational air concentration standard's failure to protect beryllium workers is driving many scientific and occupational health advances. These developments include study of bioavailability of different physicochemical forms of beryllium, medical surveillance to show effectiveness of skin protection in preventing sensitization in high-risk processes, gene-environment interaction, transgenic mice for use in experimental research, and risk-based management of industrial exposures in the absence of effective exposure-response information. Beryllium sensitization and disease prevention are paradigms for much broader public health action in both occupational and general population settings.

Enhanced preventive programme at a beryllium oxide ceramics facility reduces beryllium sensitisation among new workers

BACKGROUND

A 1998 survey at a beryllium oxide ceramics manufacturing facility found that 10% of workers hired in the previous 6 years had beryllium sensitisation as determined by the beryllium lymphocyte proliferation test (BeLPT). In response, the facility implemented an enhanced preventive programme to reduce sensitisation, including increased respiratory and dermal protection and particle migration control.

AIM

To assess the programme's effectiveness in preventing sensitisation.

METHODS

In 2000, the facility began testing newly hired workers for beryllium sensitisation with the BeLPT at time of hire and during employment. The sensitisation rate and prevalence for workers hired from 2000 to 2004 were compared with that for workers hired from 1993 to 1998, who were tested in the 1998 survey. Facility environmental conditions for both time periods were evaluated.

RESULTS

Newly hired workers in both cohorts worked for a mean of 16 months. Of the 97 workers hired from 2000 to 2004 with at least one employment BeLPT result, four had abnormal results at time of hire and one became sensitised during employment. Of the 69 workers hired from 1993 to 1998 and tested in 1998, six were found to be sensitised. The sensitisation rate for the 2000-4 workers was 0.7-2.7/1000 person-months of employment, and that for the 1993-8 workers was 5.6/1000 person-months, at least 2.1 (95% confidence interval (CI) 0.6 to 8.4) and up to 8.2 (95% CI 1.2 to 188.8) times higher than that for the 2000-4 workers. The sensitisation prevalence for the 2000-4 workers was 1% and that for the 1993-8 workers was 8.7%, 8.4 (95% CI 1.04 to 68.49) times higher than that for the 2000-4 workers. Airborne beryllium levels for production workers for the two time periods were similar.

CONCLUSIONS

A comprehensive preventive programme reduced beryllium sensitisation in new workers during the first years of employment, despite airborne beryllium levels for production workers that were similar to pre-programme levels.

Exposure Pathway Assessment at a Copper–Beryllium Alloy Facility

Controlling beryllium inhalation exposures to comply with regulatory levels (2 micro g m(-3) of air) does not appear to prevent beryllium sensitization and chronic beryllium disease (CBD). Additionally, it has proven difficult to establish a clear inhalation exposure-response relationship for beryllium sensitization and CBD. Thus, skin may be an important route of exposure that leads to beryllium sensitization. A 2000 survey had identified prevalence of sensitization (7%) and CBD (4%) in a beryllium alloy facility. An improved particulate migration control program, including dermal protection in production areas, was completed in 2002 at the facility. The purpose of this study was to evaluate levels of beryllium in workplace air, on work surfaces, on cotton gloves worn by employees over nitrile gloves, and on necks and faces of employees subsequent to implementation of the program. Over a 6 day period, we collected general area air samples (n = 10), wipes from routinely handled work surfaces (n = 252), thin cotton glove samples (n = 113) worn by employees, and neck wipes (n = 109) and face wipes (n = 109) from the same employees. In production, production support and office areas geometric mean (GM) levels of beryllium were 0.95, 0.59 and 0.05 micro g per 100 cm(2) on work surfaces; 42.8, 73.8 and 0.07 micro g per sample on cotton gloves; 0.07, 0.09 and 0.003 micro g on necks; and 0.07, 0.12 and 0.003 micro g on faces, respectively. Correlations were strong between beryllium in air and on work surfaces (r = 0.79), and between beryllium on cotton gloves and on work surfaces (0.86), necks (0.87) and faces (0.86). This study demonstrates that, even with the implementation of control measures to reduce skin contact with beryllium as part of a comprehensive workplace protection program, measurable levels of beryllium continue to reach the skin of workers in production and production support areas. Based on our current understanding of the multiple exposure pathways that may lead to sensitization, we support prudent control practices such as use of protective gloves to minimize skin exposure to beryllium salts and fine particles.

Sensitization and Chronic Beryllium Disease Among Workers in Copper???Beryllium Distribution Centers

OBJECTIVE

Little is known about the risk of sensitization and chronic beryllium disease (CBD) among workers performing limited processing of copper-beryllium alloys downstream of the primary beryllium industry. In this study, we performed a cross-sectional survey of employees at three copper-beryllium alloy distribution centers.

METHODS

One hundred workers were invited to be tested for beryllium sensitization using the beryllium blood lymphocyte proliferation test (BeLPT); a sensitized worker was further evaluated for CBD. Available beryllium mass concentration air sampling data were obtained for characterization of airborne exposure.

RESULTS

One participant, who had exposure to other forms of beryllium, was found to be sensitized and to have CBD, resulting in a prevalence of sensitization/CBD of 1% for all tested.

CONCLUSIONS

The overall prevalence of beryllium sensitization and CBD for workers in these three copper-beryllium alloy distribution centers is lower than for workers in primary beryllium production facilities.

Immunogenetic factors in beryllium sensitization and chronic beryllium disease

Exposure to beryllium in the workplace can cause beryllium sensitization and chronic beryllium disease. Sensitization to beryllium can be detected in the laboratory using the beryllium lymphocyte proliferation test. It was shown that anti-HLA antibodies could block the beryllium-specific response in the beryllium lymphocyte proliferation test, thereby implicating HLA genes in chronic beryllium disease. A supratypic genetic marker, HLA-DPB1*E69, was found to be strongly associated with immunologic sensitization to beryllium and chronic beryllium disease in beryllium workers. However, there are 40 HLA-DPB1 gene variants that have E69 but that also have other DNA sequence variations. The purpose of the study was to evaluate the evidence for potential differential susceptibility that may be associated with the physical characteristics of HLA protein molecules for which different HLA-DPB1*E69 variants code; that is, do some HLA-DPB1*E69 variants convey higher risk of beryllium sensitization and chronic beryllium disease than others. To do this, two approaches were pursued: first, detailed analysis of the findings from the published literature was performed, and second, computational chemistry was used to seek clues concerning the physical properties of the HLA protein molecules for which these alleles code. Among the 40 HLA-DPB1 gene variants that code for E69, molecular epidemiological studies have suggested a risk hierarchy, where some variants appear to convey low to moderate risk of chronic beryllium disease (e.g., HLA-DPB1*0201, approximately 3-fold increased risk), some convey an intermediate risk (e.g., HLA-DPB1*1901, approximately 5-fold) and others convey high risk (e.g., HLA-DPB1*1701, >10-fold). Molecular modeling has been used to further investigate a potential mechanistic basis for these observations. We found a strong correlation between the hierarchical order of risk of chronic beryllium disease associated with specific alleles and the predicted surface electrostatic potential and charge of the corresponding isotypes. Therefore, when alleles were grouped by the relative negative charge on the molecules for which they code, the data suggest that those alleles associated with the most negatively charged proteins carry the greatest risk of beryllium sensitization and disease.

Process-related risk of beryllium sensitization and disease in a copper-beryllium alloy facility

BACKGROUND

Chronic beryllium disease (CBD), which primarily affects the lungs, occurs in sensitized beryllium-exposed individuals. At a copper-beryllium alloy strip and wire finishing facility we performed a cross-sectional survey to examine prevalences of beryllium sensitization and CBD, and relationships between sensitization and CBD and work areas/processes.

METHODS

Current employees (185) were offered beryllium lymphocyte proliferation testing (BeLPT) for sensitization, clinical evaluation for CBD (if sensitized), and questionnaires. We obtained historical airborne beryllium measurements.

RESULTS

Participation was 83%. Prevalences of sensitization and CBD were 7% (10/153) and 4% (6/153), respectively; this included employees with abnormal BeLPTs from two laboratories, four diagnosed with CBD during the survey, and one each diagnosed preceding and following the survey. Potential BeLPT laboratory problems were noted; one laboratory was twice as likely to have reported an abnormal result (P < 0.05, all tests), and five times as likely to have reported a borderline or uninterpretable result (P < 0.05, first blood draw and all tests). CBD risk was highest in rod and wire production (P < 0.05), where air levels were highest.

CONCLUSIONS

Sensitization and CBD were associated with an area in which beryllium air levels exceeded 0.2 microg/m3, and not with areas where this level was rarely exceeded. Employees at this copper-beryllium alloy facility had similar prevalences of sensitization and CBD as workers at facilities with higher beryllium air levels.

The association between HLA-DPB1Glu69 and chronic beryllium disease and beryllium sensitization

BACKGROUND

Several case-control studies have found an association between chronic beryllium disease (CBD) and HLA-DPB1 gene variants. However, the relationship between HLA-DPB1 and beryllium sensitization, and whether the presence of one or two HLA-DPB1(Glu69) alleles is differentially associated with CBD and beryllium sensitization have not been completely resolved.

METHODS

Restriction fragment length polymorphism (RFLP) analysis was used to address these questions in a large population-based cohort consisting of 884 beryllium workers (90 with CBD, 64 beryllium sensitized).

RESULTS

HLA-DPB1(Glu69) was associated with both CBD (OR = 9.4; 95% CI = 5.4, 16.6) and sensitization (OR = 3.3, 95% CI = 1.9, 5.9). Further, workers with CBD and sensitization were more likely to be homozygous HLA-DPB1(Glu69) compared to workers without disease or sensitization (P < 0.001).

CONCLUSIONS

Follow-up of this cohort, scrutiny of HLA-DPB1 haplotypes, and evaluation of gene-environment and gene-gene interactions will be important for fully understanding the immunogenetic nature of this occupational disease.

Characterization of physicochemical properties of beryllium aerosols associated with prevalence of chronic beryllium disease

Little is known about the physicochemical properties of beryllium aerosols associated with increased risk of beryllium sensitization and chronic beryllium disease (CBD). Such information is needed to evaluate whether airborne mass of beryllium is the appropriate metric of exposure or alternatively to provide a scientific basis for using information on particle size, surface area, and chemistry to support an improved exposure limit based on bioavailability through the inhalation and dermal routes of exposure. Thus, we used a suite of analytical techniques to characterize aerodynamically size-fractionated beryllium particles and powders that have been associated in epidemiological studies with higher prevalence of CBD. Aerosol particles were sampled from the ventilation systems of production lines for powders of beryllium metal and beryllium oxide and for ingots of copper-beryllium alloy. End product powders from the metal and oxide production lines were also collected. Particles released during production of beryllium metal were found to be complex, having heterogeneous composition, including reactive species such as fluorine. Powders from beryllium metal production were of high purity with only a minor component of beryllium oxide. Both particles and powders from oxide production were high-purity oxide. Particles released during production of copper-beryllium alloy were heterogeneous, being predominantly copper oxides. Thus, all particles and powders contain at least some beryllium in the form of beryllium oxide. These data justify efforts to thoroughly characterize beryllium aerosol properties when performing exposure assessments. The data also suggest that differences in particle chemical composition, size, number, and surface area may influence bioavailability of beryllium and contribute to risk of CBD. However, a scientific basis does not yet exist to replace mass as the current metric of exposure.