Ultrafine Beryllium Number Concentration as a Possible Metric for Chronic Beryllium Disease Risk

Beryllium solubility in occupational airborne particles: Sequential extraction procedure and workplace application

Modification of an existing sequential extraction procedure for inorganic beryllium species in the particulate matter of emissions and in working areas is described. The speciation protocol was adapted to carry out beryllium extraction in closed-face cassette sampler to take wall deposits into account. This four-step sequential extraction procedure aims to separate beryllium salts, metal, and oxides from airborne particles for individual quantification. Characterization of the beryllium species according to their solubility in air samples may provide information relative to toxicity, which is potentially related to the different beryllium chemical forms. Beryllium salts (BeF(2), BeSO(4)), metallic beryllium (Bemet), and beryllium oxide (BeO) were first individually tested, and then tested in mixtures. Cassettes were spiked with these species and recovery rates were calculated. Quantitative analyses with matched matrix were performed using inductively coupled plasma mass spectrometry (ICP-MS). Method Detection Limits (MDLs) were calculated for the four matrices used in the different extraction steps. In all cases, the MDL was below 4.2 ng/sample. This method is appropriate for assessing occupational exposure to beryllium as the lowest recommended threshold limit values are 0.01 µg.m(-3) in France([) (1) (]) and 0.05 µg.m(-3) in the USA.([ 2 ]) The protocol was then tested on samples from French factories where occupational beryllium exposure was suspected. Beryllium solubility was variable between factories and among the same workplace between different tasks.

A novel alternative to environmental monitoring to detect workers at risk for beryllium exposure-related health effects

The purpose of this study was to describe a methodology for surveillance and monitoring of beryllium exposure using biological monitoring to complement environmental monitoring. Eighty-three Israeli dental technicians (mean age 41.6 ± 1.36 years) and 80 American nuclear machining workers (54.9 ± 1.21 years) were enrolled. Biological monitoring was carried out by analyzing particle size (laser technique) and shape (image analysis) in 131/163 (80.3%) induced sputum samples (Dipa Analyser, Donner Tech, Or Aquiva, Israel). Environmental monitoring was carried out only in the United States (Sioutas impactor, SKC, Inc., Eighty Four, Pa.). Pulmonary function testing performance and induced sputum retrieval were done by conventional methods. Sixty-three Israeli workers and 37 American workers were followed up for at least 2 years. Biological monitoring by induced sputum indicated that a >92% accumulation of <5 μm particles correlated significantly to a positive beryllium lymphocyte proliferation test result (OR 3.8, 95% CI 1.2-11.4, p = 0.015) among all participants. Environmental monitoring showed that beryllium particles were <1 μm, and this small fraction (0.1-1 μ) was significantly more highly accumulated in nuclear machining workers compared to dental technicians. The small fractions positively correlated with induced sputum macrophages (r = 0.21 p = 0.01) and negatively correlated with diffusion lung carbon monoxide single breath (DLCO-SB r = 0.180 p = 0.04) in all subjects. Years of exposure were positively correlated to the number of accumulated particles 2-3 μ in diameter (r = 0.2, p = 0.02) and negatively correlated to forced expiratory volume in one second/forced vital capacity findings (r = -0.18, p = 0.02). DLCO was decreased in both groups after two years of monitoring. Biological monitoring is more informative than environmental monitoring in the surveillance and monitoring of workers in beryllium industries. Induced sputum is a feasible and promising biomonitoring method that should be included in the surveillance of exposed workers.

A novel platform for pulmonary and cardiovascular toxicological characterization of inhaled engineered nanomaterials

A novel method is presented which is suitable for assessing in vivo the link between the physicochemical properties of engineered nanomaterials (ENM) and their biological outcomes. The ability of the technique to generate a variety of industry-relevant, property-controlled ENM exposure atmospheres for inhalation studies was systematically investigated. The primary particle size for Fe(2)O(3), SiO(2), Ag and Ag/SiO(2) was controlled from 4 to 25 nm, while the corresponding agglomerate mobility diameter of the aerosol was also controlled and varied from 40 to 120 nm. The suitability of the technique to characterize the pulmonary and cardiovascular effects of inhaled ENMs in intact animal models is also demonstrated using in vivo chemiluminescence (IVCL). The IVCL technique is a highly sensitive method for identifying cardiopulmonary responses to inhaled ENMs under relatively small doses and acute exposures. It is shown that moderate and acute exposures to inhaled nanostructured Fe(2)O(3) can cause both pulmonary and cardiovascular effects.

Health implications of engineered nanomaterials

With the development of nanotechnology, a growing number of people are expected to be exposed to its products, the engineered nanomaterials (ENMs). Some physico-chemical properties of ENMs, linked to their size in the nanoscale (1-100 nm), make them potentially more reactive, and therefore raise concern about possible adverse effects in humans. In this article, I discuss human diseases which may be predicted after exposure to ENMs, and how their pathogenetic mechanisms may be linked to exposure; in this regard, special emphasis has been given to the triad of oxidative stress/inflammation/genotoxicity and to the interaction of ENMs/proteins in different biological compartments. The analysis of possible adverse effects has been made on an organ-by-organ basis, starting from the skin, respiratory system and gastrointestinal tract. These sites are in fact not only those exposed to the highest amounts of ENMs, but are also the portals of entry to internal organs for possible systemic effects. Although the list and the relevance of possible human disorders linked to ENM exposure are at least as impressive as that of their direct or indirect beneficial effects for human health, we must be clear that ENM-linked diseases belong to the realm of possible risk (i.e. cannot be excluded, but are unlikely), whereas ENMs with proven beneficial effects are on the market. Therefore, the mandatory awareness about possible adverse effects of ENMs should in no way be interpreted as a motivation to disregard the great opportunity represented by nanotechnology.

Assessing potential nanoparticle release during nanocomposite shredding using direct-reading instruments

This study was conducted to determine if engineered nanoparticles are released into the air when nanocomposite parts are shredded for recycling. Test plaques made from polypropylene resin reinforced with either montmorillonite nanoclay or talc and from the same resin with no reinforcing material were shredded by a granulator inside a test apparatus. As the plaques were shredded, an ultrafine condensation particle counter; a diffusion charger; a photometer; an electrical mobility analyzer; and an optical particle counter measured number, lung-deposited surface area, and mass concentrations and size distributions by number in real-time. Overall, the particle levels produced were both stable and lower than found in some occupational environments. Although the lowest particle concentrations were observed when the talc-filled plaques were shredded, fewer nanoparticles were generated from the nanocomposite plaques than when the plain resin plaques were shredded. For example, the average particle number concentrations measured using the ultrafine condensation particle counter were 1300 particles/cm(3) for the talc-reinforced resin, 4280 particles/cm(3) for the nanoclay-reinforced resin, and 12,600 particles/cm(3) for the plain resin. Similarly, the average alveolar-deposited particle surface area concentrations measured using the diffusion charger were 4.0 μm(2)/cm(3) for the talc-reinforced resin, 8.5 μm(2)/cm(3) for the nanoclay-reinforced resin, and 26 μm(2)/cm(3) for the plain resin. For all three materials, count median diameters were near 10 nm during tests, which is smaller than should be found from the reinforcing materials. These findings suggest that recycling of nanoclay-reinforced plastics does not have a strong potential to generate more airborne nanoparticles than recycling of conventional plastics.

A strategy for assessing workplace exposures to nanomaterials

This article describes a highly tailorable exposure assessment strategy for nanomaterials that enables effective and efficient exposure management (i.e., a strategy that can identify jobs or tasks that have clearly unacceptable exposures), while simultaneously requiring only a modest level of resources to conduct. The strategy is based on strategy general framework from AIHA® that is adapted for nanomaterials and seeks to ensure that the risks to workers handling nanomaterials are being managed properly. The strategy relies on a general framework as the basic foundation while building and elaborating on elements essential to an effective and efficient strategy to arrive at decisions based on collecting and interpreting available information. This article provides useful guidance on conducting workplace characterization; understanding exposure potential to nanomaterials; accounting methods for background aerosols; constructing SEGs; and selecting appropriate instrumentation for monitoring, providing appropriate choice of exposure limits, and describing criteria by which exposure management decisions should be made. The article is intended to be a practical guide for industrial hygienists for managing engineered nanomaterial risks in their workplaces.

Risk of chronic beryllium disease by HLA-DPB1 E69 genotype and beryllium exposure in nuclear workers

RATIONALE

Beryllium sensitization (BeS) and chronic beryllium disease (CBD) are determined by at least one genetic factor, a glutamic acid at position 69 (E69) of the HLA-DPB1 gene, and by exposure to beryllium. The relationship between exposure and the E69 genotype has not been well characterized.

OBJECTIVES

The study goal was to define the relationship between beryllium exposure and E69 for CBD and BeS.

METHODS

Workers (n = 386) from a U.S. nuclear weapons facility were enrolled into a case-control study (70 BeS, 61 CBD, and 255 control subjects). HLA-DPB1 genotypes were determined by sequence-specific primer-polymerase chain reaction. Beryllium exposures were reconstructed on the basis of worker interviews and historical exposure measurements.

MEASUREMENTS AND MAIN RESULTS

Any E69 carriage increased odds for CBD (odds ratio [OR], 7.61; 95% confidence interval [CI], 3.66-15.84) and each unit increase in lifetime weighted average exposure increased the odds for CBD (OR, 2.27; 95% CI, 1.26-4.09). Compared with E69-negative genotypes, a single E69-positive *02 allele increased the odds for BeS (OR, 12.01; 95% CI, 4.28-33.71) and CBD (OR, 3.46; 95% CI, 1.42-8.43). A single non-*02 E69 allele further increased the odds for BeS (OR, 29.54; 95% CI, 10.33-84.53) and CBD (OR, 11.97; 95% CI, 5.12-28.00) and two E69 allele copies conferred the highest odds for BeS (OR, 55.68; 95% CI, 14.80-209.40) and CBD (OR, 22.54; 95% CI, 7.00-72.62).

CONCLUSIONS

E69 and beryllium exposure both contribute to the odds of CBD. The increased odds for CBD and BeS due to E69 appear to be differentially distributed by genotype, with non-*02 E69 carriers and E69 homozygotes at higher odds than those with *02 genotypes.

Exposure assessment approaches for engineered nanomaterials

Products based on nanotechnology are rapidly emerging in the marketplace, sometimes with little notice to consumers of their nanotechnology pedigree. This wide variety of nanotechnology products will result (in some cases) in unintentional human exposure to purposely engineered nanoscale materials via the dermal, inhalation, ingestion, and ocular pathways. Occupational, consumer, and environmental exposure to the nanomaterials should be characterized during the entire product lifecycle-manufacture, use, and disposal. Monitoring the fate and transport of engineered nanomaterials is complicated by the lack of detection techniques and the lack of a defined set of standardized metrics to be consistently measured. New exposure metrics may be required for engineered nanomaterials, but progress is possible by building on existing tools. An exposure metric matrix could organize existing data by relating likely exposure pathways (dermal, inhalation, ocular, ingestion) with existing measurements of important characteristics of nanoscale materials (particle number, mass, size distribution, charge). Nanomaterial characteristics not commonly measured, but shown to initiate a biological response during toxicity testing, signal a need for further research, such as the pressing need to develop monitoring devices capable of measuring those aspects of engineered nanomaterials that result in biological responses in humans. Modeling the behavior of nanoparticles may require new types of exposure models that individually track particles through the environment while keeping track of the particle shape, surface area, and other surface characteristics as the nanoparticles are transformed or become reactive. Lifecycle analysis could also be used to develop conceptual models of exposure from engineered nanomaterials.

Determination of particle concentration rankings by spatial mapping of particle surface area, number, and mass concentrations in a restaurant and a die casting plant

Measurements using several exposure metrics were carried out in a restaurant and a die casting plant to compare the spatial distributions of particle surface area (SA), number, and mass concentrations and rank exposures in different areas by those metrics. The different exposure metrics for incidental nanoparticle and fine particle exposures were compared using the concentration rankings, statistical differences between areas, and concentration ratios between different areas. In the die casting plant, area concentration rankings and spatial distributions differed by the exposure metrics chosen. Surface area and fine particle number concentrations were greatest near incidental nanoparticle sources and were significantly different between three areas. However, mass and coarse particle number concentrations were similar throughout the facility, and rankings of the work areas based on these metrics were different from those of SA and fine number concentrations. In the restaurant, concentrations in the kitchen for all metrics except respirable mass concentration were significantly greater than in the serving area, although SA and fine particle number concentrations showed larger differences between the two areas than either the mass or coarse particle number concentrations. Thus, the choice of appropriate exposure metric has significant implications for exposure groupings in epidemiologic and occupational exposure studies.

Comparing exposure zones by different exposure metrics using statistical parameters: contrast and precision

Recently, the appropriateness of using the 'mass concentration' metric for ultrafine particles has been questioned and surface area (SA) or number concentration metrics has been proposed as alternatives. To assess the abilities of various exposure metrics to distinguish between different exposure zones in workplaces with nanoparticle aerosols, exposure concentrations were measured in preassigned 'high-' and 'low-'exposure zones in a restaurant, an aluminum die-casting factory, and a diesel engine laboratory using SA, number, and mass concentration metrics. Predetermined exposure classifications were compared by each metric using statistical parameters and concentration ratios that were calculated from the different exposure concentrations. In the restaurant, SA and fine particle number concentrations showed significant differences between the high- and low-exposure zones and they had higher contrast (the ratio of between-zone variance to the sum of the between-zone and within-zone variances) than mass concentrations. Mass concentrations did not show significant differences. In the die cast facility, concentrations of all metrics were significantly greater in the high zone than in the low zone. SA and fine particle number concentrations showed larger concentration ratios between the high and low zones and higher contrast than mass concentrations. None of the metrics were significantly different between the high- and low-exposure zones in the diesel engine laboratory. The SA and fine particle number concentrations appeared to be better at differentiating exposure zones and finding the particle generation sources in workplaces generating nanoparticles. Because the choice of an exposure metric has significant implications for epidemiologic studies and industrial hygiene practice, a multimetric sampling approach is recommended for nanoparticle exposure assessment.

Advances in identifying beryllium sensitization and disease

Beryllium is a lightweight metal with unique qualities related to stiffness, corrosion resistance, and conductivity. While there are many useful applications, researchers in the 1930s and l940s linked beryllium exposure to a progressive occupational lung disease. Acute beryllium disease is a pulmonary irritant response to high exposure levels, whereas chronic beryllium disease (CBD) typically results from a hypersensitivity response to lower exposure levels. A blood test, the beryllium lymphocyte proliferation test (BeLPT), was an important advance in identifying individuals who are sensitized to beryllium (BeS) and thus at risk for developing CBD. While there is no true “gold standard” for BeS, basic epidemiologic concepts have been used to advance our understanding of the different screening algorithms.

Beryllium contamination and exposure monitoring in an inhalation laboratory setting

Beryllium (Be) is used in several forms: pure metal, beryllium oxide, and as an alloy with copper, aluminum, or nickel. Beryllium oxide, beryllium metal, and beryllium alloys are the main forms present in the workplace, with inhalation being the primary route of exposure. Cases of workers with sensitization or chronic beryllium disease challenge the scientific community for a better understanding of Be toxicity. Therefore, a toxicological inhalation study using a murine model was performed in our laboratory in order to identify the toxic effects related to different particle sizes and chemical forms of Be. This article attempts to provide information regarding the relative effectiveness of the environmental monitoring and exposure protection program that was enacted to protect staff (students and researchers) in this controlled animal beryllium inhalation exposure experiment. This includes specific attention to particle migration control through intensive housekeeping and systematic airborne and surface monitoring. Results show that the protective measures applied during this research have been effective. The highest airborne Be concentration in the laboratory was less than one-tenth of the Quebec OEL (occupational exposure limit) of 0.15 microg/m(3). Considering the protection factor of 10(3) of the powered air-purifying respirator used in this research, the average exposure level would be 0.03 x 10(- 4) microg/m(3), which is extremely low. Moreover, with the exception of one value, all average Be concentrations on surfaces were below the Quebec Standard guideline level of 3 microg/100 cm(2) for Be contamination. Finally, all beryllium lymphocyte proliferation tests for the staff were not higher than controls.

A rationale for sampling deposited submicrometer beryllium particulate matter

The established particle size-selective criteria are based on the probability of an aerosol penetrating into the lung rather than depositing. For submicrometer particulate matter, penetration is a constant 100%, while deposition fluctuates. The deposited submicrometer particulate criterion has been suggested as a more appropriate measure of exposure for particles less than 1 mu m in size. There is some preliminary evidence that these smaller particles may be of significance for chronic beryllium disease. It has also been suggested that particle number might provide a better surrogate of exposure than total mass for beryllium sampling. There are two basic approaches that can be used for sampling for a deposition based criterion. The first is to determine the overall size distribution and apply a deposition factor based on the geometric mean and geometric standard deviation to the total amount of material collected. The second approach is to have specifically designed equipment for the deposition criterion of interest. This second approach is more practical, and methods are available and are being developed to make it available to the hygienist. Although there are reasons to believe that submicrometer-deposited beryllium particles are associated with the risk of beryllium disease, these measures need to be made so that epidemiologists will have the data available to fully confirm their relevance. Where the data already exist, epidemiologists need to be aware that there is evidence supporting using it their analyses.

Physicochemical characteristics of aerosol particles generated during the milling of beryllium silicate ores: implications for risk assessment

Inhalation of beryllium dusts generated during milling of ores and cutting of beryl-containing gemstones is associated with development of beryllium sensitization and low prevalence of chronic beryllium disease (CBD). Inhalation of beryllium aerosols generated during primary beryllium production and machining of the metal, alloys, and ceramics are associated with sensitization and high rates of CBD, despite similar airborne beryllium mass concentrations among these industries. Understanding the physicochemical properties of exposure aerosols may help to understand the differential immunopathologic mechanisms of sensitization and CBD and lead to more biologically relevant exposure standards. Properties of aerosols generated during the industrial milling of bertrandite and beryl ores were evaluated. Airborne beryllium mass concentrations among work areas ranged from 0.001 microg/m(3) (beryl ore grinding) to 2.1 microg/m(3) (beryl ore crushing). Respirable mass fractions of airborne beryllium-containing particles were < 20% in low-energy input operation areas (ore crushing, hydroxide product drumming) and > 80% in high-energy input areas (beryl melting, beryl grinding). Particle specific surface area decreased with processing from feedstock ores to drumming final product beryllium hydroxide. Among work areas, beryllium was identified in three crystalline forms: beryl, poorly crystalline beryllium oxide, and beryllium hydroxide. In comparison to aerosols generated by high-CBD risk primary production processes, aerosol particles encountered during milling had similar mass concentrations, generally lower number concentrations and surface area, and contained no identifiable highly crystalline beryllium oxide. One possible explanation for the apparent low prevalence of CBD among workers exposed to beryllium mineral dusts may be that characteristics of the exposure material do not contribute to the development of lung burdens sufficient for progression from sensitization to CBD. In comparison to high-CBD risk exposures where the chemical nature of aerosol particles may confer higher bioavailability, respirable ore dusts likely confer considerably less. While finished product beryllium hydroxide particles may confer bioavailability similar to that of high-CBD risk aerosols, physical exposure factors (i.e., large particle sizes) may limit development of alveolar lung burdens.

Characterization of beryllium particles from CAlSiFrit

Aluminum smelters produce in excess thousand of tons of spent pot lining (SPL) each year. CAlSiFrit technology is a recycling process in which spent pot lining (SPL) is recovered and transformed into commercial value-added products. Since SPL contains beryllium (Be), exposures encountered by workers may result in adverse effects. This study aimed to establish the level at which Be is present in the CAlSiFrit and to determine the chemical and physical characteristics of the Be-containing particles. Three samples of CAlSiFrit powder supplied by the recycling industry were analyzed using several methods in order to (1) detect and characterize Be-containing particles, (2) identify the Be chemical form, and (3) quantify the amount of other major chemical elements present. These methods were: inductively coupled plasma-mass spectrometry, instrumental neutron activation analysis, time-of-flight secondary-ion mass spectrometry (TOF-SIMS), analytical transmission electron microscopy (ATEM), and x-ray diffraction. Results show that the three samples have a similar chemical composition, with high concentrations, of Si, Ca, Al, Na, F, Fe, K, Mg, and Ti, in decreasing order. Be concentrations were low and totaled less than 3 ppm. The size of the areas where Be was detected by TOF-SIMS is approximately 0.3 mum or less in diameter. A large quantity of oxygen in the particles of dusts was observed. As the majority of elements present have a great affinity for oxygen, the presence of oxygen indicates that these elements are probably oxides. Finally, the particle size varied from approximately 0.05 to 1 mum. This is consistent with the interpretation of the TOF-SIMS results that suggest a size of approximately 0.3 mum or less for the particles containing Be. These results are important from the perspective that thousands of tons of CAlSiFrit, a supplementary cement material, might be produced and used.

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.

Dermal exposure to beryllium: a pilot case study

The issue of dermal absorption of beryllium (Be) particles through intact healthy skin has not yet been demonstrated. The interest in Be dermal exposure as a potential pathway for toxic effects was emphasized in Quebec (Canada) when a recycling industry processing spent pot lining (SPL) related to the aluminum industry was recently requested by health authorities to conduct a Be particle size study and to provide a Tyvek coverall for full skin protection of workers. This study aimed to (1) calculate the dermal and inhalation exposures and (2) apply the results to the case study of a recycling SPL industry. Airborne dust was sampled in order to determine Be particles size. Exposure assessment via the skin and the respiratory routes was measured over a working day using standard calculations. The assessment of workers' clothing protection was obtained by swiping the skin on the forearm and upper front leg before and after exposure. Respirable Be (0.044 microg) was 23% of the total Be (0.19 microg). Be particles with a median mass aerodynamic diameter (MMAD) of 0.93 and below totaled 0.0103 microg (5% of BeT). The daily dose for the respiratory route was calculated to be 0.022 microg/kg/d, while the daily doses for the dermal route varied between 0.027 x 10(-7) microg/kg/d and 0.025 x 10(-3) microg/kg/d. After exposure, no Be was found on the skin of workers wearing a cotton coverall protection. When using a polyester coverall, minor amounts of Be were found. These results showed that dermal daily dose exposure is negligible. However, note that the case study did not involve handling of contaminated items by the workers, which lead to significant dermal exposure if care is not taken. Although daily dermal exposure may be small, because of uncertainties, a precautionary principle should be applied in an active sense.

Trace-level beryllium analysis in the laboratory and in the field: state of the art, challenges and opportunities

Control of workplace exposure to beryllium is a growing issue in the United States and other nations. As the health risks associated with low-level exposure to beryllium are better understood, the need increases for improved analytical techniques both in the laboratory and in the field. These techniques also require a greater degree of standardization to permit reliable comparison of data obtained from different locations and at different times. Analysis of low-level beryllium samples, in the form of air filters or surface wipes, is frequently required for workplace monitoring or to provide data to support decision-making on implementation of exposure controls. In the United States and the United Kingdom, the current permissible exposure level is 2 microg m(-3) (air) and the United States Department of Energy has implemented an action level of 0.2 microg m(-3) (air) and 0.2 microg/100 cm(2) (surface). These low-level samples present a number of analytical challenges, including (1) a lack of suitable standard reference materials, (2) unknown robustness of sample preparation techniques, (3) interferences during analysis, (4) sensitivity (sufficiently low detection limits), (5) specificity (beryllium speciation) and (6) data comparability among laboratories. Additionally, there is a need for portable, real-time (or near real-time) equipment for beryllium air monitoring and surface wipe analysis that is both laboratory-validated and field-validated in a manner that would be accepted by national and/or international standards organizations. This paper provides a review of the current analytical requirements for trace-level beryllium analysis for worker protection and also addresses issues that may change those requirements. The current analytical state of the art and relevant challenges facing the analytical community will be presented, followed by suggested criteria for real-time monitoring equipment. Recognizing and addressing these challenges will present opportunities for laboratories, research and development organizations, instrument manufacturers and others.

Physical and chemical characterization of beryllium particles from several workplaces in Québec, Canada--part A: determining methods for the analysis of low levels of beryllium

Chemical and physical characterizations of beryllium (Be) particles found in settled dust samples from four industries based in Québec were attempted using a variety of analytical methods. Bulk particle chemistry was determined using inductively coupled plasma-mass spectrometry (ICP-MS), graphite furnace atomic absorption spectrometry (GFAAS), and instrumental neutron activation analysis (INAA). Time-of-flight secondary-ion mass spectrometry (TOF-SIMS), transmission electron microscopy, scanning electron microscopy, energy-dispersive spectroscopy, x-ray diffraction (XRD), electron energy loss spectrometry (EELS), and Auger microscopy were used to characterize physicochemical properties of particles. These analyses were deemed important based on the hypotheses that (1) different chemical forms of Be do not present the same risks, and (2) different morphologies lead to different risks. Standards were used to prove the adequacy of XRD, EELS, and Auger microscopy prior to the analyses of industrial samples. However, low concentrations of Be in samples were a limiting factor for most methods; few detected Be in industrial samples. Only ICP-MS, GFAAS, and TOF-SIMS were able to detect Be in industrial samples analyzed in this study. Characterization of settled dust samples showed high number of Be particles, even for Be concentrations below 100 ppm. Furthermore, Be seems to be present as fine particles of Be metal, possibly mechanically agglomerated or aggregated to larger particles or compounds such as cryolite. Other major elements detected with INAA present in the samples were limited to Na, Al, Ca, and F. It was concluded that TOF-SIMS is a valid method for characterizing particles containing approximately 0.01% Be.

Chronic beryllium disease and sensitization at a beryllium processing facility

We conducted a medical screening for beryllium disease of 577 former workers from a beryllium processing facility. The screening included a medical and work history questionnaire, a chest radiograph, and blood lymphocyte proliferation testing for beryllium. A task exposure and a job exposure matrix were constructed to examine the association between exposure to beryllium and the development of beryllium disease. More than 90% of the cohort completed the questionnaire, and 74% completed the blood and radiograph component of the screening. Forty-four (7.6%) individuals had definite or probable chronic beryllium disease (CBD), and another 40 (7.0%) were sensitized to beryllium. The prevalence of CBD and sensitization in our cohort was greater than the prevalence reported in studies of other beryllium-exposed cohorts. Various exposure measures evaluated included duration; first decade worked; last decade worked; cumulative, mean, and highest job; and highest task exposure to beryllium (to both soluble and nonsoluble forms). Soluble cumulative and mean exposure levels were lower in individuals with CBD. Sensitized individuals had shorter duration of exposure, began work later, last worked longer ago, and had lower cumulative and peak exposures and lower nonsoluble cumulative and mean exposures. A possible explanation for the exposure-response findings of our study may be an interaction between genetic predisposition and a decreased permanence of soluble beryllium in the body. Both CBD and sensitization occurred in former workers whose mean daily working lifetime average exposures were lower than the current allowable Occupational Safety and Health Administration workplace air level of 2 microg/m3 and the Department of Energy guideline of 0.2 microg/m3.

Screening for beryllium disease among construction trade workers at Department of Energy nuclear sites

BACKGROUND

To determine whether current and former construction workers are at significant risk for occupational illnesses from work at the Department of Energy's (DOE) nuclear weapons facilities, screening programs were undertaken at the Hanford Nuclear Reservation, Oak Ridge Reservation, and the Savannah River Site.

METHODS

Medical examination for beryllium disease used a medical history and a beryllium blood lymphocyte proliferation test (BeLPT). Stratified and multivariate logistic regression analyses were used to explore the risk of disease by age, race, sex, trade, duration of DOE employment, reported work in buildings where beryllium was used, and time since last DOE site employment.

RESULTS

Of the 3,842 workers included in this study, 34% reported exposure to beryllium. Overall, 2.2% of workers had at least one abnormal BeLPT test, and 1.4% were also abnormal on a second test. Regression analyses demonstrated increased risk of having at least one abnormal BeLPT to be associated with ever working in a site building where beryllium activities had taken place.

CONCLUSIONS

The prevalence of beryllium sensitivity and chronic beryllium disease (CBD) in construction workers is described and the positive predictive value of the BeLPT in a population with less intense exposure to beryllium than other populations that have been screened is discussed. The BeLPT findings and finding of cases of CBD demonstrate that some of these workers had significant exposure, most likely, during maintenance, repair, renovation, or demolition in facilities where beryllium was used.

Effects of nanophase materials (< or = 20 nm) on biological responses

Nanophase materials have enhanced properties (thermal, mechanical, electrical, surface reactivity, etc.) not found in bulk materials. Intuitively, the enhancement of material properties could occur when the materials encounter biological specimens. Previous investigations of biological interactions with nanometer-scale materials have been very limited. With the ability to manipulate atoms and molecules, we now can create predefined nanostructures with unprecedented precision. In parallel with this development, improved understanding of the biological effects of the nanophase materials, whatever those may be, should also deserve attention. In this study, we have applied precision aerosol technology to investigate cellular response to nanoparticles. We used synthetic nanoparticles generated by an electrospray technique to produce nanoparticles in the size range of 8-13 nm with practically monodispersed aerosol particles and approximately the same number concentration. We report here on the potency of nano-metal particles with single or binary chemical components in eliciting interleukin-8 (IL-8) production from epithelial cell lines. For single-component nanoparticles, we found that nano-Cu particles were more potent in IL-8 production than nano-Ni and nano-V particles. However, the kinetics of IL-8 production by these three nanoparticles was different, the nano-Ni being the highest among the three. When sulfuric acid was introduced to form acidified nano-Ni particles, we found that the potency of such binary-component nanoparticles in eliciting IL-8 production was increased markedly, by about six times. However, the acidified binary nano-Na and -Mg nanoparticles did not exhibit the same effects as binary nano-Ni particles did. Since Ni, a transition metal, could induce free radicals on cell surfaces, while Na and Mg could not, the acidity might have enhanced the oxidative stress caused by radicals to the cells, leading to markedly higher IL-8 production. This result indicates the complexity of biological responses to nanoparticles. We believe that the exposure methodology and aerosol technology employed in our research will provide an effective means to systematically investigate cellular responses to nanoparticles, structured or unstructured, in ongoing research projects. Different cell lines, chemicals, and particle morphology can also be investigated using such a methodology.