The beryllium bronchoalveolar lavage lymphocyte proliferation test: indicator of beryllium sensitization, inflammation or both?

Context: We had available records on over 300 workers evaluated with the beryllium bronchoalveolar lavage lymphocyte proliferation test (BeBALLPT) at three expert chronic beryllium disease (CBD) diagnostic centers.

Objective: The objective was to describe the contribution of the BeBALLPT to classification of workers with respect to beryllium sensitization (BeS) and beryllium-induced lung inflammation.

Methods: Company records were used to identify beryllium workers who had undergone diagnostic bronchoscopy with BeBALLPT.

Occupational Cohort Time Scales.

Purpose: This study explores how highly correlated time variables (occupational cohort time scales) contribute to confounding and ambiguity of interpretation.

Methods: Occupational cohort time scales were identified and organized through simple equations of three time scales (relational triads) and the connections between these triads (time scale web). The behavior of the time scales was examined when constraints were imposed on variable ranges and interrelationships.

Bias from using occupational smoking prevalence to adjust occupational incidence cohort lung cancer mortality rates.

Objective: To describe how smoking correction factors based on comparing worker smoking prevalence with population smoking prevalence are biased if applied to an occupational incidence cohort.

Methods: Relative rates of smoking for shorter-tenure workers derived from occupational cohort lung cancer studies were applied to incidence and prevalence population tenure distributions to calculate relative smoking estimates.

Results: High smoking rates in short-tenure workers have little effect on prevalent worker rates (relative smoking estimates, 1.

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.

Implications of common and special variation for occupational health: examples from beryllium manufacturing.

Objective: Common variation is a statistical process-control term for variability associated with usual operating conditions. Special variation occurs when usual operating conditions are disrupted. The objective was to explore the implications for preventive occupational medicine practice of common and special variation in air-level exposure.

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).

Solubility and chemistry of materials encountered by beryllium mine and ore extraction workers: relation to risk.

Objective: Beryllium mine and ore extraction mill workers have low rates of beryllium sensitization and chronic beryllium disease relative to the level of beryllium exposure. The objective was to relate these rates to the solubility and composition of the mine and mill materials.

Method: Medical surveillance and exposure data were summarized.

Sensitization and chronic beryllium disease at a primary manufacturing facility, part 3: exposure-response among short-term workers.

Objectives: Exposure-response relations for beryllium sensitization (BeS) and chronic beryllium disease (CBD) using aerosol mass concentration have been inconsistent, although process-related risks found in most studies suggest that exposure-dependent risks exist. We examined exposure-response relations using personal exposure estimates in a beryllium worker cohort with limited work tenure to minimize exposure misclassification.

Methods: The population comprised workers employed in 1999 with six years or less tenure.

Dissolution and nanoparticle generation behavior of Be-associated materials in synthetic lung fluid using inductively coupled plasma mass spectroscopy and flow field-flow fractionation.

Various Be-containing micro-particle suspensions were equilibrated with simulated lung fluid (SLF) to examine their dissolution behavior as well as the potential generation of nanoparticles. The motivation for this study was to explore the relationship between dissolution/particle generation behaviors of Be-containing materials relevant to Be-ore processing, and their epidemiologically indicated inhalation toxicities. Limited data suggest that BeO is associated with higher rates of beryllium sensitization (BS) and chronic beryllium disease (CBD) relative to the other five relevant materials studied: bertrandite-containing ore, beryl-containing ore, frit (a processing intermediate), Be(OH)₂ (a processing intermediate), and silica (control).

Evaluation of a preventive program to reduce sensitization at a beryllium metal, oxide, and alloy production plant.

Objective: We evaluated a workplace preventive program's effectiveness, which emphasized skin and respiratory protection, workplace cleanliness, and beryllium migration control in lowering beryllium sensitization.

Methods: We compared sensitization prevalence and incidence rates for workers hired before and after the program using available cross sectional and longitudinal surveillance data.

Results: Sensitization prevalence was 8.

Long-term follow-up of beryllium sensitized workers from a single employer.

Background: Up to 12% of beryllium-exposed American workers would test positive on beryllium lymphocyte proliferation test (BeLPT) screening, but the implications of sensitization remain uncertain.

Methods: Seventy two current and former employees of a beryllium manufacturer, including 22 with pathologic changes of chronic beryllium disease (CBD), and 50 without, with a confirmed positive test were followed-up for 7.4 +/-3.

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.

Exposure to beryllium and occurrence of lung cancer: findings from a cox proportional hazards analysis of data from a retrospective cohort mortality study.

Objective: The objective was to assess highly confounded patterns in a standardized mortality ratio (SMR) analysis of lung cancer in beryllium worker cohorts.

Methods: We used Cox proportional hazards single- and multi-variate models to assess confounding and the SMR patterns.

Results: We confirmed the lack of association of lung cancer with time worked.

Cumulative sensitization and disease in a beryllium oxide ceramics worker cohort.

Objective: We followed a cohort of 136 beryllium oxide ceramics workers from 1992 to 2003, including those who left employment, for beryllium sensitization and chronic beryllium disease (CBD).

Methods: We invited the cohort's participation in current worker surveys in 1992, 1998, 2000, and 2002-2003, and in former worker surveys in 2000-2001 and 2003. We calculated 11-year cumulative incidences (after 1992 initial survey) of sensitization and CBD, both crude and corrected for interval censoring; and period prevalences (including 1992 findings), crude and corrected.

Empirical evaluation of complex epidemiologic study designs: workplace exposure and cancer.

Objective: To test whether a frequently used cohort-nested case-control study design exaggerated exposure-response relationships because of unrecognized study design bias. Our aim was to evaluate empirically the performance of this complex study design.

Methods: We applied the design from one such study to a closely related cohort using randomly selected probands as cases.

Exposure to beryllium and occurrence of lung cancer: a reexamination of findings from a nested case-control study.

Objective: Our aim was to reanalyze a nested case-control study of beryllium and lung cancer because we identified analysis and study design issues that could have led to the elevated odds ratios obtained in the study.

Methods: We reanalyzed the data using nontransformed exposure metrics instead of log-transformed metrics used in the publication. We identified and examined effects on estimated odds ratios of imbalances between cases and controls caused by the control selection method.

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.

Assessment of the beryllium lymphocyte proliferation test using statistical process control.

Despite more than 20 years of surveillance and epidemiologic studies using the beryllium blood lymphocyte proliferation test (BeBLPT) as a measure of beryllium sensitization (BeS) and as an aid for diagnosing subclinical chronic beryllium disease (CBD), improvements in specific understanding of the inhalation toxicology of CBD have been limited. Although epidemiologic data suggest that BeS and CBD risks vary by process/work activity, it has proven difficult to reach specific conclusions regarding the dose-response relationship between workplace beryllium exposure and BeS or subclinical CBD. One possible reason for this uncertainty could be misclassification of BeS resulting from variation in BeBLPT testing performance.

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.

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.

Role of the berylliosis-associated HLA-DPGlu69 supratypic variant in determining the response to beryllium in a blood T-cells beryllium-stimulated proliferation test.

Background And Aim Of The Work: Exposure to beryllium (Be) compounds may cause sensitization as revealed by blood T-cell proliferation against Be in a standardized Be-stimulated T-cell proliferation test (BeLPT). Further, susceptibility to Be hypersensitivity has been associated with the expression of HLA-DP allelic variants carrying a glutamate residue at position 69 of the beta-chain (HLA-DPGlu69) in more than 80% of affected subjects and, at lower frequency, with other HLA-DP, -DQ and -DR alleles/polymorphisms. The aim of this study was to assess whether heterozygous or homozygous carriage of the HLA-DPGlu69 marker may dictate the intensity of the T-cell response to Be in vitro.