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Exposure to ceramic powders, which is frequent during handling operations, is known to cause adverse health effects. Finding proxy parameters to quantify exposure is useful for efficient and timely exposure assessments. Worker exposure during handling of five materials [a silica sand (SI1), three quartzes (Q1, Q2, and Q3), and a kaolin (K1)] with different particle shape (prismatic and platy) and sizes (3.4-120 µm) was assessed. Materials handling was simulated using a dry pendular mill under two different energy settings (low and high). Three repetitions of two kilos of material were carried out per material and energy conditions with a flow rate of 8-11 kg h-1. The performance of the dustiness index as a predictor of worker exposure was evaluated correlating material's dustiness indexes (with rotating drum and continuous drop) with exposure concentrations. Significant impacts on worker exposure in terms of inhalable and respirable mass fractions were detected for all materials. Mean inhalable mass concentrations during background were always lower than 40 µg m-3 whereas during material handling under high energy settings mean concentrations were 187, 373, 243, 156, and 430 µg m-3 for SI1, Q1, Q2, Q3, and K1, respectively. Impacts were not significant with regard to particle number concentration: background particle number concentrations ranged between 10 620 and 46 421 cm-3 while during handling under high energy settings they were 20 880 - 40 498 cm-3. Mean lung deposited surface area during background ranged between 27 and 101 μm2 cm-3 whereas it ranged between 22 and 42 μm2 cm-3 during materials handling. TEM images evidenced the presence of nanoparticles (≤100 nm) in the form of aggregates (300 nm-1 µm) in the worker area, and a slight reduction on mean particle size during handling was detected. Dustiness and exposure concentrations showed a high degree of correlation (R2 = 0.77-0.97) for the materials and operating conditions assessed, suggesting that dustiness could be considered a relevant predictor for workplace exposure. Nevertheless, the relationship between dustiness and exposure is complex and should be assessed for each process, taking into account not only material behaviour but also energy settings and workplace characteristics.

Exposure to airborne agents needs to be assessed in the personal breathing zone by the use of personal measurement equipment. Specific measurement devices for assessing personal exposure to airborne nanomaterials have only become available in the recent years. They can be differentiated into direct-reading personal monitors and personal samplers that collect the airborne nanomaterials for subsequent analyses. This article presents a review of the available personal monitors and samplers and summarizes the available literature regarding their accuracy, comparability and field applicability. Due to the novelty of the instruments, the number of published studies is still relatively low. Where applicable, literature data is therefore complemented with published and unpublished results from the recently finished nanoIndEx project. The presented data show that the samplers and monitors are robust and ready for field use with sufficient accuracy and comparability. However, several limitations apply, e.g. regarding the particle size range of the personal monitors and their in general lower accuracy and comparability compared with their stationary counterparts. The decision whether a personal monitor or a personal sampler shall be preferred depends strongly on the question to tackle. In many cases, a combination of a personal monitor and a personal sampler may be the best choice to obtain conclusive results., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Personal monitors based on unipolar diffusion charging (miniDiSC/DiSCmini, NanoTracer, Partector) can be used to assess the individual exposure to nanoparticles in different environments. The charge acquired by the aerosol particles is nearly proportional to the particle diameter and, by coincidence, also nearly proportional to the alveolar lung-deposited surface area (LDSA), the metric reported by all three instruments. In addition, the miniDiSC/DiSCmini and the NanoTracer report particle number concentration and mean particle size. In view of their use for personal exposure studies, the comparability of these personal monitors was assessed in two measurement campaigns. Altogether 29 different polydisperse test aerosols were generated during the two campaigns, covering a large range of particle sizes, morphologies and concentrations. The data provided by the personal monitors were compared with those obtained from reference instruments: a scanning mobility particle sizer (SMPS) for LDSA and mean particle size and a ultrafine particle counter (UCPC) for number concentration. The results indicated that the LDSA concentrations and the mean particle sizes provided by all investigated instruments in this study were in the order of ±30% of the reference value obtained from the SMPS when the particle sizes of the test aerosols generated were within 20-400nm and the instruments were properly calibrated. Particle size, morphology and concentration did not have a major effect within the aforementioned limits. The comparability of the number concentrations was found to be slightly worse and in the range of ±50% of the reference value obtained from the UCPC. In addition, a minor effect of the particle morphology on the number concentration measurements was observed. The presence of particles >400nm can drastically bias the measurement results of all instruments and all metrics determined., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Responsible development of any technology, including nanotechnology, requires protecting workers, the first people to be exposed to the products of the technology. In the case of nanotechnology, this is difficult to achieve because in spite of early evidence raising health and safety concerns, there are uncertainties about hazards and risks. The global response to these concerns has been the issuance by authoritative agencies of precautionary guidance to strictly control exposures to engineered nanomaterials (ENMs). This commentary summarizes discussions at the "Symposium on the Health Protection of Nanomaterial Workers" held in Rome (25 and 26 February 2015). There scientists and practitioners from 11 countries took stock of what is known about hazards and risks resulting from exposure to ENMs, confirmed that uncertainties still exist, and deliberated on what it would take to conduct a global assessment of how well workers are being protected from potentially harmful exposures.

Objective: Dust sample mass gain is too smaller to satisfy the limit of detection (LOD) even in most cases during dust sampling at workplaces nowdays, especially for respirable fraction. Therefore, it is aimed to solve the problem by increasing sample load with high flow rate samplers., Methods: In A and B two shipyards respirable welding fume was sampled by high flow rate cyclone samplers of FSP-10 (10 L/min) for 2-2.5 hours and normal flow rate FSP-2 (2 L/min) for 3-4 hours with a stratigy of parallele sampling at the same workpalce, in order to compare their mass gain, coincidence rate with LOD, and airborn dust concentration., Results: Sample mass gain of 0.97±0.40 mg and 1.61±0.86 mg respectively in the two factories by FSP-10 was significantly higher than that of 0.29±0.12 mg and 0.51±0.27 mg by FSP-2 (t-test, P<0.05 in both cases) , increasing herewith the coincidence rate with LOD from 26.8% (when sampling with FSP-2, calculated together with samples of the two factories) to 89.7%. However there was no significant difference in dust concentrations by the two different samplers, 0.53±1.88 vs 0.73±1.61 mg/m(3) by FSP-2 and FSP-10 in the shipyard A and 1.14±1.78 vs 1.01±1.63 mg/m(3) in the factory B (t-test, P>0.05 in every case) . In addtion, sample loading by FSP-2 was found to be correlated to sampling time (R(2)=0.7906, y=0.002 6x) , therefore, it has to sample for ≥192.3 min to meet the LOD (0.5 mg) in case of normal flow rate., Conclusion: By using of high flow rate cyclone FSP-10 the problem of LOD could be solved, along with increased sample mass and similar respirable dust concentration by the two samplers. Some techincal improvements of FSP-10 and increasing of LOD coincidence rate by other methods was also disscussed.

Objectives: Working in mines and quarries has been associated with an elevated lung cancer risk but with inconsistent results for coal miners. This study aimed to estimate the smoking-adjusted lung cancer risk among coal miners and compare the risk pattern with lung cancer risks among ore miners and quarrymen., Methods: We estimated lung cancer risks of coal and ore miners and quarrymen among 14 251 lung cancer cases and 17 267 controls from the SYNERGY pooled case-control study, controlling for smoking and employment in other at-risk occupations., Results: Ever working as miner or quarryman (690 cases, 436 controls) was associated with an elevated odds ratio (OR) of 1.55 [95% confidence interval (95% CI) 1.34-1.79] for lung cancer. Ore miners (53 cases, 24 controls) had a higher OR (2.34, 95% CI 1.36-4.03) than quarrymen (67 cases, 39 controls; OR 1.92, 95% CI 1.21-3.05) and coal miners (442 cases, 297 controls; OR 1.40, 95% CI 1.18-1.67), but CI overlapped. We did not observe trends by duration of exposure or time since last exposure., Conclusions: This pooled analysis of population-based studies demonstrated an excess lung cancer risk among miners and quarrymen that remained increased after adjustment for detailed smoking history and working in other at-risk occupations. The increase in risk among coal miners were less pronounced than for ore miners or quarrymen.

Objective: Workplace aerosol sampling is challenged by its influencing factors and methodological limitations. Some factors, including blank setting, electrostatic effect, sample mass gain, and limit of detection (LOD), were studied to characterize them further and thereby to improve the sampling method., Methods: Through a field sampling in two shipyards and by an analysis of a large amount of dust data from different industries, the influencing factors were comparatively studied with emphasis on their effect on the final result., Results: After calibration with field blanks, the concentrations of most sample types in the shipyards decreased significantly, varying by as much as -24.3% of the final measurements. After laboratory blank calibration, dust concentrations increased or decreased without a definite change trend. With a variation of -1.8%, only the measurements of Chinese "total dust" sampled with polypropylene filters were significantly influenced by the electrostatic effect. The LOD coincidence rate was only 17.3% for American respirable dust in different industries and 12.2% for respirable particles collected by normal flow rate samplers (FSP2) in the shipyards. The latter increased to 73.9% when high flow samplers (FSP10) were used., Conclusions: It was suggested that field blank calibration was the predominant influencing factor in comparison with electrostatic effect and laboratory blank adjustment. The LOD coincidence rate was too low for reliable sampling, and this might be improved by use of high flow samplers.

Five different portable instrument types to monitor exposure to nanoparticles were subject to an intensive intercomparison measurement campaign. Four of them were based on electrical diffusion charging to determine the number concentration or lung deposited surface area (LDSA) concentration of airborne particles. Three out of these four also determined the mean particle size. The fifth instrument type was a handheld condensation particle counter (CPC). The instruments were challenged with three different log-normally distributed test aerosols with modal diameters between 30 and 180 nm, varying in particle concentration and morphology. The CPCs showed the highest comparability with deviations on the order of only ±5%, independent of the particle sizes, but with a strictly limited upper number concentration. The diffusion charger-based instruments showed comparability on the order of ±30% for number concentration, LDSA concentration, and mean particle size, when the specified particle size range of the instruments matched the size range of the aerosol particles, whereas significant deviations were found when a large amount of particles exceeded the upper or lower detection limit. In one case the reported number concentration was even increased by a factor of 6.9 when the modal diameter of the test aerosol exceeded the specified upper limit of the instrument. A general dependence of the measurement accuracy of all devices on particle morphology was not detected.

In China, dust samplers were originally designed to collect 'total dust' for a short term during production, which is different from the widely adopted sampling strategy for dust. With the aim to provide the conversion factor from Chinese total dust to US and German respirable dust and to look at the influences on conversion factors from environment, production, and instruments, a comparative field study on the dust concentration measurements by different sampling methods was carried out in the same Chinese industries as in the 1989-1990 study and in some other factories. A supplemental experiment was also conducted in a wind tunnel. Dust concentration was measured with a parallel sampling strategy by using the following samplers: 10-mm nylon cyclone for US respirable dust (AR), FSP-Berufsgenossenschaftliches Institut für Arbeitssicherheit (BIA) cyclone for German respirable dust (GR), and samplers for Chinese total dust (CT). Totally, 1434 samples were collected (269 AR, 198 GR, and 967 CT), from which 429 matched sample pairs (249 pairs of AR/CT, 180 GR/CT) were available to calculate conversion ratios. Industry- and job-based conversion factors are presented in this study. The conversion factor of AR/CT was 0.38 for tungsten mines, 0.19 for copper/iron mines, 0.65 for tin mines, and 0.20 for pottery industry, while the factor of GR/CT was 0.69 for tungsten, 0.37 for copper/iron, and 0.52 for pottery. In the job category, AR/CT factors varied from 0.16 to 0.96 and GR/CT from 0.12 to 0.72. For the industries studied in 1988-1989, the AR/CT and GR/CT factors were 0.29 and 0.45, respectively. Both factors were definitely influenced by production, CT dust concentration, sample gain, and variation of dust concentration. Moreover, the respirable dust concentration by FSP-BIA was significantly higher than that by 10-mm cyclones, 63.27-73.10% more as showed also by the wind tunnel experiment. Meanwhile, the GR/CT ratio was significantly larger than the AR/CT in every industry or job with only few exceptions. The GR/CT estimates should be considered as independent ones. Following these results, there is a need to use 'ideal samplers' (consistent with the internationally accepted respirable fraction) in practice and to assess the existent samplers in order to homogenize the exposure data situation.

Background: SYNERGY is a large pooled analysis of case-control studies on the joint effects of occupational carcinogens and smoking in the development of lung cancer. A quantitative job-exposure matrix (JEM) will be developed to assign exposures to five major lung carcinogens [asbestos, chromium, nickel, polycyclic aromatic hydrocarbons (PAH), and respirable crystalline silica (RCS)]. We assembled an exposure database, called ExpoSYN, to enable such a quantitative exposure assessment., Methods: Existing exposure databases were identified and European and Canadian research institutes were approached to identify pertinent exposure measurement data. Results of individual air measurements were entered anonymized according to a standardized protocol., Results: The ExpoSYN database currently includes 356 551 measurements from 19 countries. In total, 140 666 personal and 215 885 stationary data points were available. Measurements were distributed over the five agents as follows: RCS (42%), asbestos (20%), chromium (16%), nickel (15%), and PAH (7%). The measurement data cover the time period from 1951 to present. However, only a small portion of measurements (1.4%) were performed prior to 1975. The major contributing countries for personal measurements were Germany (32%), UK (22%), France (14%), and Norway and Canada (both 11%)., Conclusions: ExpoSYN is a unique occupational exposure database with measurements from 18 European countries and Canada covering a time period of >50 years. This database will be used to develop a country-, job-, and time period-specific quantitative JEM. This JEM will enable data-driven quantitative exposure assessment in a multinational pooled analysis of community-based lung cancer case-control studies.

This study investigates the association between lymph node-only and lung silicosis in uranium miners with lung cancer and exposure to quartz dust. Tissue slides of 4,384 German uranium miners with lung cancer were retrieved from an autopsy archive and reviewed by 3 pathologists regarding silicosis in the lungs and lymph nodes. Cumulative exposure to quartz dust was assessed with a quantitative job-exposure matrix. The occurrence of silicosis by site was investigated with regression models for exposure to quartz dust. Miners with lung silicosis had highest cumulative quartz exposure, followed by lymph node-only silicosis and no silicosis. At a cumulative quartz exposure of 40 mg/m(3) × years, the probability of lung silicosis was above 90% and the likelihood of lymph node-only silicosis and no silicosis do not differ anymore. The results support that lymph node silicosis can precede lung silicosis, at least in a proportion of subjects developing silicosis, and that lung silicosis strongly depends on the cumulative quartz dose., (Copyright © 2011 Taylor & Francis Group, LLC)

A time-dependent quantitative exposure assessment of silica exposure among nearly 18,000 German porcelain workers was conducted. Results will be used to evaluate exposure-response disease risks. Over 8000 historical industrial hygiene (IH) measurements with original sampling and analysis protocols from 1954-2006 were obtained from the German Berufs- genossenschaft der keramischen-und Glas-Industrie (BGGK) and used to construct a job exposure matrix (JEM). Early measurements from different devices were converted to modern gravimetric equivalent values. Conversion factors were derived from parallel historical measurements and new side-by-side measurements using historical and modern devices in laboratory dust tunnels and active workplace locations. Exposure values were summarized and smoothed using LOESS regression; estimates for early years were derived using backward extrapolation techniques. Employee work histories were merged with JEM values to determine cumulative crystalline silica exposures for cohort members. Average silica concentrations were derived for six primary similar exposure groups (SEGs) for 1938-2006. Over 40% of the cohort accumulated <0.5 mg; just over one-third accumulated >1 mg/m(3)-years. Nearly 5000 workers had cumulative crystalline silica estimates >1.5 mg/m(3)-years. Similar numbers of men and women fell into each cumulative exposure category, except for 1113 women and 1567 men in the highest category. Over half of those hired before 1960 accumulated >3 mg/m(3)-years crystalline silica compared with 4.9% of those hired after 1960. Among those ever working in the materials preparation area, half accumulated >3 mg/m(3)-year compared with 12% of those never working in this area. Quantitative respirable silica exposures were estimated for each member of this cohort, including employment periods for which sampling used now obsolete technologies. Although individual cumulative exposure estimates ranged from background to about 40 mg/m(3)-years, many of these estimates reflect long-term exposures near modern exposure limit values, allowing direct evaluation of lung cancer and silicosis risks near these limits without extrapolation. This quantitative exposure assessment is the largest to date in the porcelain industry.

Purpose: Workplace limits for dust and nitrogen oxides are under review in Germany and the EU. We conducted a study on German coal miners to determine the effects of exposure on lung function., Methods: Longitudinal inception cohort study (1974-1998) on miners who began working underground at two coal mines between 1974 and 1979. We determined the number of shifts worked underground, the exposure to coal mine dust, quartz dust, nitrogen oxides (NO, NO(2)), smoking behavior, and three lung function parameters (FVC, FEV(1), FEV(1)/FVC). General estimation equation (GEE) models were fitted., Results: 1,369 miners worked an average 3,017 shifts (S) underground. The mean respirable coal mine dust concentration was 1.89 mg/m(3) (quartz: 0.067 mg/m(3)), and the nitrogen oxide concentrations were 0.58 ppm (NO) and 0.007 ppm (NO(2)). On average, 9 measurements of lung function were available per miner. Compared to reference values, the findings were unexceptionable (103, 101, and 99%) on average. GEE-regression models did not reveal detrimental dust exposure effects. Nitrogen oxides (NO (x) = NO + NO(2)) showed small but clearly insignificant effects on lung function: delta FVC = -0.0008 ml/(220 ppmS), P = 0.86, delta FEV(1) = -0.003 ml/(220 ppmS), P = 0.50 and delta FEV(1)%FVC = -0.07%/(220 ppmS), P = 0.22., Conclusions: The effect of dust exposure on lung function described in older British and American coal miner studies was not confirmed. This can be explained partly by differences in methods (here: longitudinal studies, no prior exposure), but also by lower dust levels. NO (x) exposures showed no relevant influence on lung function-a result confirming findings from British coal mining.

A range of industrial minerals was tested using the rotating drum and the continuous drop methods, the two methods proposed by the published European standard EN 15051 [CEN. (2006) EN 15051 Workplace atmospheres-measurement of the dustiness of bulk materials-requirements and test methods. Brussels, Belgium: European Committee for Standardization], to evaluate and compare their dustiness. The assessment of bulk materials dustiness can help to develop less dusty products and to reduce dust exposure to the workers by improving the processing of minerals. The European standard EN 15051 (CEN, 2006) proposes a classification system that was developed with the intention to assist in the labelling of products in the future. This paper presents a comparison of both test methods in classifying industrial minerals. The correlation between the dustiness measured by the two methods for the inhalable and respirable fractions is given. The results show there is no unambiguous dependence of the dustiness on the grain size of an industrial mineral. Although dustiness can significantly be affected by product moisture, the influence of this parameter is not studied in detail as the industrial minerals were tested in the conditions they are sold, as the standard requires. Especially, the classification of substances with respect to different classes of dustiness was found to be problematic, as the two methods are by no means yielding identical classification groups for all the substances. In any use of the standard (EN 15051; CEN, 2006) for labelling purposes, a revision of the present classification system provided in the standard is required for industrial minerals.

Objective: The exposure situation of German hard coal miners with respect to the components nitrogen monoxide and nitrogen dioxide. Carbon monoxide was measured additionally and the results are displayed but not discussed in detail in this paper. The data were used to estimate personal long-term exposures in an inception cohort., Methods: For all three components, time weighted 8-h shift values were determined for typical groups of coalminers according to the European measurement standard. An expert panel from the coal mining company made an effort to estimate major potential changes in the exposure situation., Results: The main sources of nitrogen oxides and carbon monoxide in hard coal mining were the diesel engines. Blasting fumes contributed only to a lesser degree and with different exposure characteristics, e.g. much reduced NO(2) levels compared to the mines' rear areas. As rough 8 h-shift averages describing the current exposure situation, we found 1.35 ppm NO and 0.21 ppm NO(2) for the diesel engine drivers. Blasting specialists were more difficult to evaluate but rough 8 h-shift averages of 0.84 ppm NO and 0.014 ppm NO(2) could be estimated from our measurement series. By applying these data and the estimates of experts about the retrospective exposure situation to a cohort of 1,369 coalminers, we derived mean (max) cumulative exposures in ppm x number of shifts of 1,748 (5,928) for NO and 19.6 (1,013) for NO(2) when summarizing over the follow-up period from 1974 until 1998., Conclusions: Especially for the diesel engine drivers, exposure can be regarded as rather high, in particular, when compared to recommended limits by SCOEL and MAK, though the exposures have been in line with the enforced German occupational exposure limits. Whether this exposure situation has caused adverse health effects will be investigated epidemiologically.

Exposure to crystalline silica ranks among the most frequent occupational exposures to an established human carcinogen. Health-based occupational exposure limits can only be derived from a reliable dose-response relationship. Although quartz dust seems to be a well-measurable agent, several uncertainties in the quantification of exposure to crystalline silica can bias the risk estimates in epidemiological studies. This review describes the silica-specific methodological issues in the assessment of exposure. The mineralogical forms of silica, the technologies applied to generate dust, protective measures, and co-existing carcinogens are important parameters to characterize the exposure condition of an occupational setting. Another methodological question concerns the measurement of the respirable dust fraction in the worker's breathing zone and the determination of the quartz content in that fraction. Personal devices have been increasingly employed over time, whereas norms for the measurement of respirable dust have been defined only recently. Several methods are available to analyse the content of crystalline silica in dust with limits of quantitation close to environmental exposure levels. For epidemiological studies, the quartz content has frequently not been measured but only calculated. To develop a silica-dust database for epidemiological purposes, historical dust concentrations sampled with different devices and measured as particle numbers have to be converted in a common exposure metric. For the development of a job-exposure matrix (JEM), missing historical data have to be estimated to complete the database over time. Unknown but frequently high-exposure levels of the past contribute largely to the cumulative exposure of a worker. Because the establishment of a JEM is crucial for risk estimates, sufficient information should be made accessible to allow an estimation of the uncertainties in the assessment of exposure to crystalline silica. The impressive number of silica dust measurements and the evaluation of methodological uncertainties allow recommendations for a best practice of exposure assessment for epidemiological studies.

Objectives: Starting shortly after the reunification of Germany and lasting up to the end of the 1990s, an extensive series of retrospective exposure investigations for the East German uranium mining industry was performed in order to provide information about the exposure situation of the miners towards respirable dust, inhalable dust, crystalline silica and heavy metals. It should provide the necessary information for legal compensation of miners with potential industrial diseases as well as for epidemiological research., Methods: Extensive side-by-side measurements using original historic equipments as well as comprehensive evaluation of the time increments of specific jobs with respect to exposure relevant tasks were performed. After attributing average exposures to the tasks, shift exposures for the jobs could be calculated., Results: By the end a comprehensive job exposure matrix for all underground jobs of the German uranium mining industry was developed for the components mentioned, including arsenic where relevant. In the early days of SAG/SDAG Wismut dust and silica exposures were extremely high with respirable dust up to 20 mg/m(3) and respirable crystalline silica well above 2 mg/m(3) as shift averages. Beginning from about the early 1960s dust control measures started to improve conditions dramatically., Conclusions: It is absolutely necessary to invest sufficient effort for the estimation of exposure situations of past technological environments. Especially, the situation of early mechanised mining, characterised by low ventilation, dry drilling techniques and generally lacking dust control measures was characterized by extreme shift exposures. It is important to keep these in mind when metal mining exposure in different environments is considered.

Objective: Between 1995 and 2003 a longitudinal study on miners in two German potash mines was planned and performed by BAuA in collaboration with K+S and IGF. Aim was to correlate exposure data to the results of medical examination of the miners in the respective mines' workforce and to use the detailed exposure investigation as a tool for risk assessment by the company. In this time period a discussion about health effects and the corresponding necessity to lower the existing threshold limits for the components NO and NO(2) was started as well. Whereas the epidemiological aspects of this study are reported elsewhere (Lotz et al., in Int Arch Occup Environ Health, 2006), we discuss the exposure situation in detail in this paper., Methods: In two potash mines in Germany the shift and short time exposure for the components respirable dust, inhalable dust, diesel particulate matter, nitrogen monoxide, nitrogen dioxide, and carbon dioxide was investigated in four separate campaigns. The results are reported and discussed., Results: The miners especially in the production areas of the mines are exposed to a highly correlated mixture of the components though the exposure situation can be regarded as state of the art and representative for the industry., Conclusion: All dose-response discussions must take into account that never only one of the components can be made responsible for an eventually occurring respiratory effect. For reasons of availability of proper measurement equipment limitations for a possible lowering of indicative limit values of the EU are to be observed.

With beginning of the year 2004 a new documentation sheet for occupational preventive medical examinations according to exposures to mineral dust (quartz, asbestos, ceramic fibres) will replace the existing sheet. The new investigation sheet is presented in this publication and changes are described.

A field study was conducted in two mines in order to determine the most suitable strategy for ambient exposure assessment in the framework of a European study aimed at validation of biological monitoring approaches for diesel exhaust (BIOMODEM). Exposure to dust and particle-associated 1-nitropyrene (1-NP) was studied in 20 miners of black coal by the long wall method (Czech Republic) and in 20 workers in oil shale mining by the room and pillar method (Estonia). The study in the oil shale mine was extended to include 100 workers in a second phase (main study). In each mine half of the study population worked underground as drivers of diesel-powered trains (black coal) and excavators (oil shale). The other half consisted of workers occupied in various non-diesel production assignments. Exposure to diesel exhaust was studied by measurement of inhalable and respirable dust at fixed locations and by personal air sampling of respirable dust. The ratio of geometric mean inhalable to respirable dust concentration was approximately two to one. The underground/surface ratio of respirable dust concentrations measured at fixed locations and in the breathing zones of the workers was 2-fold or greater. Respirable dust was 2- to 3-fold higher in the breathing zone than at fixed sampling locations. The 1-NP content in these dust fractions was determined by gas chromatography-mass spectrometry/mass spectrometry and ranged from 0.003 to 42.2 ng/m(3) in the breathing zones of the workers. In mine dust no 1-NP was detected. In both mines 1-NP was observed to be primarily associated with respirable particles. The 1-NP concentrations were also higher underground than on the surface (2- to 3-fold in the coal mine and 10-fold or more in the oil shale mine). Concentrations of 1-NP in the breathing zones were also higher than at fixed sites (2.5-fold in the coal mine and 10-fold in the oil shale mine). For individual exposure assessment personal air sampling is preferred over air sampling at fixed sites. This study also suggests that particle-associated 1-NP much better reflects the ambient exposure to diesel exhaust particles than dust concentrations. Therefore, measurement of particle-associated 1-NP is preferred over measurement of dust concentrations by gravimetry, when linking ambient exposure to biomonitoring outcomes such as protein and DNA adducts and excretion of urinary metabolites of genotoxic substances.

Objectives: The European Co-ordination on Diesel Soot Exposure (ECDSE) working group organised a laboratory inter-comparison which integrated both the sampling and the analytical determination. The aim was to gain more information on the performance of the methods for the determination of diesel particulate matter at workplaces and on their comparability, and to also confirm that the requirements of the European standard EN 482 are fulfilled for this analytical procedure., Methods: Sampling was carried out in a diesel aerosol test chamber where participants used their own sampling devices. Overall, ten sampling exercises at two different concentration levels were performed and both personal air sampling systems and stationary samplers were used. The analytical determination was performed according to the laboratory's own standard procedure., Results: There was good agreement between the laboratories for the determination of organic carbon (OC), elemental carbon (EC) and total carbon (TC). Almost all the results when expressed as a coefficient of variation were in the range +/-30% of the overall means. The results also showed that the coefficient of variation for OC was approximately twice the coefficient of variation for EC. This is not too critical, because existing occupational exposure levels (OELs) are based on the measurement of EC., Conclusions: The inter-comparison showed that existing analytical procedures for the determination of diesel particulate matter at workplaces fulfil the requirements of European standard EN 482. Both personal air samplers and stationary samplers give comparable results. The parameters for the analytical determination are not critical within the range of parameter values presented in this article. Additionally, it may be concluded that the diesel aerosol test chamber used in this exercise is well suited for producing an atmosphere containing a constant and reproducible level of diesel particulate matter.

Methods for the assessment of exposures to diesel exhaust were evaluated, including various biomarkers of internal exposure and early biological effects. The impact of possible biomarkers of susceptibility was also explored. Underground workers (drivers of diesel-powered excavators) at an oil shale mine in Estonia were compared with surface workers. Personal exposures to particle-associated 1-nitropyrene (NP) were some eight times higher underground than on the surface. Underground miners were also occupationally exposed to benzene and polycyclic aromatic hydrocarbons, as indicated by excretion of urinary metabolites of benzene and pyrene. In addition, increased O(6)-alkylguanine DNA adducts were detected in the white blood cells of underground workers, suggesting higher exposure to nitroso-compounds. However, no differences between underground and surface workers were observed in the levels of other bulky DNA adducts determined by 32P-postlabelling, or in DNA damage. The study indicated that smoking, diet and residential indoor air pollution are important non-occupational factors to consider when interpreting biomonitoring results.

Diesel exhaust is considered a probable human carcinogen by the IARC. Biomonitoring of workers occupationally exposed to diesel exhaust was performed to determine their internal burden of diesel associated aromatic compounds. Personal air sampling also allowed to determine the exposure of the miners at their work place towards several polycyclic aromatic hydrocarbons (PAH) and nitro-arenes, the latter of which are thought to be specific constituents of diesel exhaust. For biomonitoring the urine of 18 underground salt miners was collected during and after their shift for 24-hours. half of the 18 miners were smokers. The urinary levels of 1-hydroxypyrene and hydroxylated phenanthrene metabolites were determined as biomarkers of PAH exposure, whereas urinary levels of some aromatic amines were chosen to monitor exposure towards specific nitro-arenes from diesel exhaust like 1-nitropyrene and 3-nitrobenzanthrone and to monitor the human burden by these compounds from inhaled cigarette smoke. Non-smoking workers exposed to diesel exhaust excrete an average level of about 4 micrograms phenanthrene metabolites, whereas the urinary levels in smokers were up to 3-fold higher. In summary the results indicate that (i) diesel exposure led to an increase of PAH metabolism in the workers examined, most probably by an induction of cytochrome P450 (ii) smokers could be identified in accordance with earlier studies by their increased ratio of phenanthrene metabolites derived from 1,2- and 3,4-oxidation and their higher amounts of excreted 1-naphthylamine, and (iii) the excreted amounts of aromatic amines found as metabolites of the nitro-arenes were about 5- to 10-fold higher as one might expect from the levels determined by personal air sampling at the workplace of the individuals.

Objectives: An informal European coordination group organized two round-robin tests on filters collected from environmental, workplace and diluted diesel emissions. Previous inter-laboratory comparisons have shown that experimental samples give reasonably good results in terms of the dispersion around the mean, from all the participating laboratories. However, there were significant differences between the laboratories owing to a narrow distribution of the results within a single laboratory. In order to gain a better understanding of the differences obtained between the laboratories, it was decided to carry out more round-robin tests and to investigate further the possible factors which may influence the results., Methods: The first round-robin (RRT3) was performed on six different samples (eight replicates) analyzed by ten laboratories. The range of loading was 40 to 138 micrograms cm-2 of total carbon (TC). Laboratories used their own thermal procedure parameters. The second round-robin test (RRT4) was performed on three different diluted diesel emissions (two replicates) samples analyzed by 13 laboratories. The range of loading was 21 to 37 micrograms cm-2 TC. Laboratories analyzed samples using imposed temperatures (500, 650 and 800 degrees C) and imposed duration (12 min)., Results: Inter-laboratory coefficients of variation for diluted diesel emission samples were 10% for RRT3 and ranged from 6 to 19% for RRT4. The influence of the desorption temperature was clearly demonstrated and the results tended to show that a desorption temperature of 650 degrees C could be an acceptable compromise. The influence of the organic carbon/elemental carbon (OC/EC) ratio was shown to be insignificant with pure diesel soot samples., Conclusions: It was expected that a significant improvement would be seen in the inter-laboratory dispersion by the use of a common standardized thermal desorption program, but the objectives of these RRTs were only partly reached. This paper provides new information that will be useful in the elaboration of a standardized procedure for the European Normalisation Centre (CEN TC 137 WG2--General requirements for measuring procedures).

Two carbon analysis methods are currently being applied to the occupational monitoring of diesel particulate matter. Both methods are based on thermal techniques for the determination of organic and elemental carbon. In Germany, method ZH 1/120.44 has been published. This method, or a variation of it, is being used for compliance measurements in several European countries, and a Comité Européen de Normalization Working Group was formed recently to address the establishment of a European measurement standard. In the USA, a 'thermal-optical' method has been published as Method 5040 by the National Institute for Occupational Safety and Health. As with ZH 1/120.44, organic and elemental carbon are determined through temperature and atmosphere control, but different instrumentation and analysis conditions are used. Although the two methods are similar in principle, they gave statistically different results in a previous interlaboratory comparison. Because different instruments and operating conditions are used, between-method differences can be expected in some cases. Reasonable agreement is expected when the sample contains no other (i.e., non-diesel) sources of carbonaceous particulate and the organic fraction is essentially removed below about 500 degrees C. Airborne particulate samples from some mines may meet these criteria. Comparison data on samples from mines are important because the methods are being applied in this workplace for occupational monitoring and epidemiological studies. In this paper, results of a recent comparison on samples collected in a Canadian mine are reported. As seen in a previous comparison, there was good agreement between the total carbon results found by the two methods, with ZH 1/120.44 giving about 6% less carbon than Method 5040. Differences in the organic and elemental carbon results were again seen, but they were much smaller than those obtained in the previous comparison. The relatively small differences in the split between organic and elemental carbon are attributed to the different thermal programs used.

Background: Findings from experimental studies on rodents and from epidemiological studies suggest that diesel exhaust may cause lung cancer. There is evidence that in several occupations, e.g., truck drivers and railway workers, the risk of lung cancer increases with duration of employment, and exposure to diesel exhaust provides the most likely explanation for these elevations of risk., Methods: We investigated the association between lung cancer mortality and exposure to diesel exhaust in a cohort study. The cohort comprised 5, 536 male potash miners who were followed from 1970 to 1994. Exposure was assessed from concentration measurements of the total carbon (i. e., elemental and organic carbon in total) in personal dust samples. The concentration values were multiplied by years of exposure to give a quantitative exposure measure. The concentration levels ranged from 0.12 to 0.39 mg/m(3) total carbon in fine dust. Work histories and smoking habit data were obtained from medical company records. Causes of death were ascertained from death certificates., Results: During the follow-up period, 424 deaths were recorded, including 133 of cancer, 38 of lung cancer. The relative risk of lung cancer between two groups with high and low exposure was 2.2 (95% confidence interval 0.8-6.0). With Cox regression, we found a lung cancer relative risk 1.7 (0.5-5.8) after twenty years of exposure. Extensive scrutiny proved smoking not to be a confounder in this study., Conclusions: The principal finding of the study is a doubling of relative lung cancer risk after twenty years of exposure in the workplaces with highest exposure. However, the observed elevation is nonsignificant even at a 90% level. Further follow-up is intended to enhance the study power., (Copyright 1999 Wiley-Liss, Inc.)

Object: Diesel soot has been recognized as probably carcinogenic to humans. Elemental carbon (also called black carbon) in soot is considered at the moment as the most significant surrogate to be measured for assessing the exposure to this pollutant. Its analysis is done by combustion in an oven and determination of the CO2 formed, after elimination of the organic fraction of the soot by heating and/or by solvent extraction. The analysis allows determination of both fractions of the soot: "elemental carbon" (EC) and organic carbon (OC). The sum of EC and OC is called TC (total carbon)., Method: An informal European coordination group organized two round robin tests on filter samples collected from diluted diesel emissions. The first round (RRT1) was performed on 13 different samples analyzed by ten laboratories. The range of loading was 2.5 to 150 micrograms/cm2 of EC. No evaluation of the precision within laboratories could be made since each laboratory gave only one result per sample. Therefore a second round (RRT2) was organized with two samples and a blank filter sent in several portions to 11 laboratories. It should be stressed that each laboratory used its own method and that no standardization was planned at this stage., Results: Results of RRT1 showed that the coefficient of variation between laboratories decreased with higher loading and was around 10% to 15% for EC above about 20 micrograms/cm2. Dispersion of the results varied and it appeared that the way OC is removed from the soot is probably the most important factor of influence. The correlation between the laboratories was good as a whole but some systematic differences could be detected. Besides the different techniques to remove the organic carbon, the pretreatment of the filter by HCl (either as a vapor or as a solution) to remove the inorganic carbonates (potential interference sources), is probably also a significant factor of influence in the dispersion of the results between laboratories. It is not yet clear from these results whether the "environmental" laboratories give different results from the "occupational" laboratories, but it is clear that their objectives differ since for the "environmentalists", EC is not a specific marker of diesel emmissions, in contrast to the "occupationalists"., Conclusion: It can be concluded that, although significant differences exist between laboratories they can be attributed mainly to the narrow distribution of the results within a single laboratory, and that the overall agreement of the results for EC and TC is fairly good. These results obtained with pure diesel engine emissions, should be complemented by field samples, but they have already achieved relevant findings in the performance of the procedures used to assess exposure to diesel soot.

"The objective of this article is to introduce panel survey data and to demonstrate its value for geographical mobility research [in the United States]. A brief history of panel surveys is provided that emphasizes the blossoming of this form of data collection during the past two decades. The potential utility of the Census Bureau's new Survey of Income and Program Participation is discussed at some greater length.", (excerpt)