Search

From the exposition database ‘MEGA’, established by the Institute for Occupational Safety and Health of the German Social Accident Insurance, measurements of inhalable dust (n=103 825) and respirable dust (n=222 501) were selected to create conversion functions of inhalable to respirable dust concentrations in different workplaces. These functions are important for exposure assessment or retrospective evaluations of exposure situations and for epidemiologic studies, when just one fraction was analyzed. For the determination of the conversion functions, 15 120 pairs of inhalable and respirable dust, which were measured in parallel, were formed. The assignment was done considering various variables such as sampling date and time or workplaces. The measured values were log-transformed and a linear regression analysis was done, calculating a conversion function for the whole dataset with an adjusted R2 > 0.580 and R>0.760. On the basis of technical information, the dataset was divided into different dust groups considering material and working activities as relevant variables, resulting in six working activity, three material, four working activity-material combination and eleven heuristic groups. For each of these groups a conversion function was calculated as well and will be described in the presentation. The models admissibility was evaluated by examining the assumptions of linear regression such as no autocorrelation, normal distribution of residuals and variance homogeneity. On the basis of that, future measurements in different workplaces and the dust exposure can easier be evaluated, when measurements of just one fractions were made and the other can be estimated using the conversion functions.

Die Probenahme für leichtflüchtige und reaktive Analyten stellt in einigen Fällen eine Herausforderung dar. So wurde für die Probenahme von Ethylenoxid die für die Umweltprobenahme etablierte Technik der Kanisterprobenahme erstmalig für Arbeitsplatzmessungen angewandt. Es wurden Machbarkeitsuntersuchungen durchgeführt, die unter anderem den linearen Bereich, die Reproduzierbarkeit, den Einfluss von Umweltbedingungen und die Stabilität umfassten. Für diese Machbarkeitsstudie zur Funktion der Kanister wurden exemplarisch Pentan- und Hexan-Isomere als Analyten zusätzlich zu Ethylenoxid ausgesucht, da diese eine geringere Toxizität aufweisen und analytisch gut bestimmbar sind. Die Regression aller Analyten befand sich in dem selektierten linearen Bereich bei > 0,999 mit guten Reproduzierbarkeiten. Ein signifikanter Einfluss der Luftfeuchte oder -temperatur konnte weder für Ethylenoxid noch für die Alkane festgestellt werden. Die Lagerstabilitäten waren über den gesamten Prüfzeitraum (14 Tage) konstant. Ein Einsatz der Probenahmekanister im Rahmen von Arbeitsplatzmessungen ist möglich. Messungen auf Ethylenoxid an Arbeitsplätzen sollen die Eignung der Kanister abschließend bestätigen.

Kurzfassung Zur Quantifizierung von Prüfgaszusammensetzungen an der dynamischen Prüfgasstrecke kommen unterschiedliche Techniken zum Einsatz. Neben konventioneller Online-Gaschromatographie (GC) wird die Selected-Ion-Flow-Tube-Massenspektrometrie (SIFT-MS) zur selektiven Quantifizierung in Echtzeit eingesetzt. Es wurden Methoden für verschiedene Substanzklassen und Konzentrationsbereiche entwickelt. Beide Techniken wurden bereits erfolgreich bei Eignungsprüfungen eingesetzt. Die Ergebnisse zeigen, dass die Technik der SIFT-MS auch im Vergleich zu etablierteren Methoden zufriedenstellende Ergebnisse liefert. Der wesentliche Vorteil dieser Technik ist die Analyse in Echtzeit, wodurch auch kurzfristige Änderungen in der Prüfgaszusammensetzung erkannt werden und somit die Qualitätssicherung weiter verbessert wird. Durch diesen Vorteil konnte ein neu konzipiertes Dosiersystem zur Prüfgaserzeugung von Substanzen mit hohem Dampfdruck mit SIFT-MS am Beispiel kurzkettiger Aldehyde verifiziert werden. Zudem bietet die SIFT-MS das Potenzial der direkten Analytik von reaktiven, kurzkettigen Very Volatile Orga-nic Compounds (VVOC) aus Probenahmekanistern und kann damit auch für die Messung von Gefahrstoffen, z. B. Ethylenoxid an Arbeitsplätzen, genutzt werden.

Neben vielen anderen Gefahrstoffen stellen einige kurzkettige Amine und starke Säuren, die heutzutage beim Sandgussverfahren eingesetzt werden, eine Gefahr für die Beschäftigten dar. Für Amine und ρ-Toluolsulfonsäure existierten bislang jedoch keine Messverfahren. Um die Exposition der Beschäftigten gegenüber diesen Gefahrstoffen zu quantifizieren und somit in Zukunft überwachen zu können, hat das Institut für Arbeitsschutz der Deutschen Gesetzlichen Unfallversicherung (IFA) geeignete Messmethoden entwickelt und validiert. In beiden Fällen handelt es sich um ionenchromatographische Messverfahren, welche die allgemeinen Anforderungen der Norm DIN EN 482 an die Leistungsfähigkeit von Messverfahren zur Messung chemischer Gefahrstoffe in Arbeitsbereichen erfüllen und sich für Messungen an Arbeitsplätzen entsprechend der Technischen Regel für Gefahrstoffe (TRGS) 402 eignen. Die Methoden wurden zur Absicherung der Methodeneignung bei Vor-Ort-Messungen, teilweise unter Reasonable-Worst-Case-Bedingungen, eingesetzt. Beide Methoden werden als Standardmessverfahren im Messsystem Gefährdungsermittlung der Unfallversicherungsträger (MGU) etabliert. Im Fall der Aminmethode wurden erfolgreich Vergleichsmessungen im Rahmen einer Methodenprüfung mit einer akkreditierten Messstelle an der dynamischen Prüfgasstrecke des IFA durchgeführt. Die Messstelle hat eine gaschromatographische Methode entwickelt. Die geprüften Methoden sollen in der MAK-Collection (MAK: Maximale Arbeitsplatz Konzentration) der Deutschen Forschungsgemeinschaft (DFG) in der Sammlung „Begründungen und Methoden“ veröffentlicht werden.

The tendency for decreasing a series of occupational exposure limit values is seen the last years. Especially metal species are linked to a larger health effect in latest toxicological assessments. These changes imply further reductions of the limits of quantification for both the sampling and analysis methods. The personal sampling methods (as a set of sampler, filter and pump) used today comprise air flows up to 10 l/min. In order to achieve higher amounts of sampled aerosols an airflow of 20 l/min is aimed for a new set of samplers for the inhalable and respirable dust fraction. This also enables shorter sampling times than a full shift, e.g. task based exposure assessment. A small set of prototypes was designed to go into testing. A filter size of 47 mm was chosen to realise a higher dust load and an acceptable pressure drop for a personal air sampling pump. Such a pump was recently developed and is now available. Samplers for the inhalable fraction with different numbers and orientation of orifices are tested in a calm air dust chamber and a wind tunnel according to the test standard EN 13205 in the particle size range up to 100 µm. A cyclone design according to the GK family of cyclones (Mesalabs) was chosen to meet the respirable convention. First test results will be shown, either in comparison with validated samplers or in terms of the sampling efficiency in dependence of the aerodynamic diameter.

For the production of filters coated with metal oxides an aqueous metal salt solution is injected into a hydrogen/oxygen flame of a particle generator leading to the pyrolysis of the metal salts into nano-scaled metal oxide dust. The particles are introduced into a large sampling chamber (20 m³) via a dust tunnel (20 m). So far, the system was tested for Zn, Cu, Pb, Co, Ni, Mn and In but it should be suitable with all metals obtainable as soluble metal salts. For sample generation an eight-fold sampling system was developed for the GSP sampler. The constancy of the flow rate is assured by critical orifices. Up to fourteen of these systems can be operated to produce 112 samples in parallel. Nevertheless, for the production of a reference material a significantly higher number of samples will be needed. To achieve this aim the environmental conditions of the dust generation have to be stabilized for consecutive runs. The major problem was the temperature rise of the dust channel during the particle generation due to the heat of the flame. An additional heater was installed to work at a constant temperature of 30 °C. Three consecutive filter series were manufactured. The achieved temperature constancy of 30± 0.5 °C makes it possible to combine the successive filter series. The loadings of the combined series were Cobalt: 3.25±0.058 µg/filter, Nickel: 13.78±0.23 µg/filter, Lead: 109.5±3.0, Copper: 9.65 ±0.18 µg/filter and Zinc: 32.66±0.72 µg/filter.

Objective This cross-sectional study determined whether acute sensory irritative or (sub)chronic inflammatory effects of the eyes, nose or respiratory tract are observed in employees who are exposed to naphthalene at the workplace. Methods Thirtynine healthy and non-smoking male employees with either moderate (n = 22) or high (n = 17) exposure to naphthalene were compared to 22 male employees from the same plants with no or only rare exposure to naphthalene. (Sub)clinical endpoint measures included nasal endoscopy, smell sensitivity, self-reported work-related complaints and the intensity of naphthalene odor and irritation. In addition, cellular and soluble mediators in blood, nasal lavage fluid (NALF) and induced sputum (IS) were analysed. All measurements were carried out pre-shift on Monday and post-shift on Thursday. Personal air monitoring revealed naphthalene shift concentrations up to 11.6 mg/m3 with short-term peak concentrations up to 145.8 mg/m3 and 1- and 2-naphthol levels (sum) in post-shift urine up to 10.1 mg/L. Results Acute sensory irritating effects at the eyes and upper airways were reported to occur when directly handling naphthalene (e.g., sieving pure naphthalene). Generally, naphthalene odor was described as intense and unpleasant. Habituation effects or olfactory fatigue were not observed. Endoscopic examination revealed mild inflammatory effects at the nasal mucosa of exposed employees in terms of reddening and swelling and abnormal mucus production. No consistent pattern of cellular and soluble mediators in blood, NALF or IS was observed which would indicate a chronic or acute inflammatory effect of naphthalene in exposed workers. Conclusions The results suggest that exposure to naphthalene induces acute sensory irritative effects in exposed workers. No (sub)chronic inflammatory effects on the nasal epithelium or the respiratory tract could be observed under the study conditions described here.

Im neuen Laborgebäude des Instituts für Arbeitsschutz der Deutschen Gesetzlichen Unfallversicherung (IFA) wurde auch eine neue, deutlich vergrößerte und leistungsfähigere dynamische Prüfgasstrecke (PGS) aufgebaut. Mit 30 m Länge und 80 mm Innendurchmesser ermöglicht sie bei laminarem Fluss einen Durchsatz von bis zu 12 m³/h. Die klimatischen Bedingungen werden vollautomatisch gesteuert. Für die Prüfgaskonditionierung und Prüfgasdosierung steht nun ein gesonderter Raum zur Verfügung, was den simultanen Einsatz von bis zu vier voneinander unabhängigen Dosiersystemen zulässt. Nach dem Aufbau der PGS gab es umfangreiche Testserien. Die Dosierung von flüchtigen organischen Stoffen wurde in verschiedenen Konzentrationsbereichen geprüft. Sowohl bei Konzentrationen im mg/m³-Bereich (z. B. für Lösemittel an Arbeitsplätzen) als auch für Konzentrationen im µg/m³-Bereich (z. B. bei Innenraumluftproben) erfüllte die PGS die gestellten Anforderungen. Alle Entnahmestellen sind gleichwertig und die erzeugten Prüfgase über einen Zeitraum von mehreren Stunden stabil. Die Anlage wurde bereits erfolgreich bei den Ringversuchen von flüchtigen organischen Verbindungen (volatile organic compounds, VOC) und Aldehyden eingesetzt. Aufgrund der aktuellen Situation (COVID-19) konnten noch keine Ringversuche mit Probenahme vor Ort angeboten werden. Ab 2021 können aber bis zu 25 Teilnehmer parallel an der neuen PGS Proben entnehmen.

Semi-volatile organic compounds (SVOCs), partitioned between particulates and vapours of an aerosol, require special attention. The toxicological effects caused by the inhalation of such aerosols may depend on the concentration and in which phase the organic compounds are found. A personal denuder-gas–particle separation aerosol sampler was developed to provide information about the partitioning of aerosols from organic compounds. The sampler was tested in a series of controlled laboratory experiments, which confirmed the capability and accuracy of the sampler to measure gas–particle mixtures. An average difference of 14.8 ± 4.8% was found between sampler and reference laboratory instruments. The obtained results showed that our sampler enables a more accurate measurement of the SVOC aerosols’ gas–particle fractionation, compared with that of conventional samplers.

Cobalt is a commonly used element in metal industry. Exposure to workers occurs mainly by inhalation of cobalt-containing dust. For the evaluation of cobalt exposure, risk assessment and investigations on occupational diseases, measurements of cobalt in respirable dust are needed. Up to now, often only data for cobalt in inhalable dust are available, which is due to the earlier classification of the limit value in this fraction. Therefore, a possibility to convert cobalt concentrations mathematically from inhalable into respirable concentrations is desirable. In this study, 639 parallel measurements of cobalt concentrations in inhalable (c

The ubiquitous use of phthalates in various materials and the knowledge about their potential adverse effects is of great concern for human health. Several studies have uncovered their role in carcinogenic events and suggest various phthalate-associated adverse health effects that include pulmonary diseases. However, only limited information on pulmonary toxicity is available considering inhalation of phthalates as the route of exposure. While in vitro studies are often based on submerged exposures, this study aimed to expose A549 alveolar epithelial cells at the air-liquid interface (ALI) to unravel the genotoxic and oxidative stress-inducing potential of dibutyl phthalate (DBP) with concentrations relevant at occupational settings. Within this scope, a computer modelling approach calculating alveolar deposition of DBP particles in the human lung was used to define in vitro ALI exposure conditions comparable to potential occupational DBP exposures. The deposited mass of DBP ranged from 0.03 to 20 ng/cm2 , which was comparable to results of a human lung particle deposition model using an 8 hours workplace threshold limit value (TLV) of 580 μg/m3 proposed by the Scientific Committee on Occupational Exposure Limits (SCOEL) for the European Union. Comet and Micronucleus assay revealed that DBP induced genotoxicity at DNA and chromosome level in sub-cytotoxic conditions. Since genomic instability was accompanied by increased generation of the lipid peroxidation marker malondialdehyde (MDA), oxidative stress might play an important role in phthalate-induced genotoxicity. The results highlight the importance of adapting in vitro studies to exposure scenarios relevant at occupational settings and reconsidering occupational exposure limits for DBP.

Up to date, information on the validity of human biomonitoring (HBM) parameters of naphthalene exposure is poor. This study was performed to reveal the relation between occupational exposure to naphthalene and biological exposure markers. Therefore, ten lowly and highly exposed workers from the abrasives industry were selected to characterise a broad exposure range. Naphthalene in air was determined by personal air monitoring during one shift. For biological monitoring, pre- and post-shift urine samples collected on 2 days of a working week were analysed for 1,2-dihydroxynaphthalene (1,2-DHN), 1- and 2-naphthol, 1- and 2-naphthylmercapturic acid (NMA). The naphthalene concentration in air was in the range of 0.5 to 11.6 mg/m3. The biomarkers in urine showed post-shift concentration in the range of 114–51,809 µg/L for 1,2-DHN, 0.8–666 µg/L for 1–NMA, 2–2698 µg/L for 1-naphthol and 4–1135 µg/L for 2-naphthol, respectively. 2-NMA was not detected. The urinary levels increased significantly from pre- to post-shift for all analysed parameters and an accumulation over the working week was observed. Significant positive correlations were observed between 1,2-DHN, 1-NMA, 1- and 2-naphthol in post-shift urine samples and personal exposure to naphthalene in the air. 1-NMA and 1,2-DHN, 1- and 2-naphthol have been demonstrated as suitable biomarkers for naphthalene exposure monitoring. Of the determined biomarkers, 1,2-DHN is by far the metabolite with the highest concentration in the urine samples.

The conversion of dust components is of high importance for retrospective evaluations of exposure levels, of occupational diseases or the time trend of occupational dust exposure. For this purpose, possibilities to convert nickel concentrations from inhalable to respirable dust are discussed in this study. Therefore, 551 parallel measurements of nickel concentrations in inhalable and respirable dust fractions were extracted from the exposure database MEGA (maintained at the Institute for Occupational Safety and Health of the German Social Accident Insurance) and investigated by linear regression analysis of ln-transformed concentrations. Inhalable dust is the most important predictor variable, showing an adjusted coefficient of determination (adj. R2) of 0.767 (R2 adjusted to sample size). Since multilinear regression analysis, cannot be applied, further description of data is gained by splitting the whole dataset into working activity groups (e. g. ‘high temperature processing’, adj. R2 = 0.628,’ filling/transport/storage’ adj. R2 = 0.741, ‘machining/abrasive techniques’, adj. R2 = 0.777). From these groups, four task restrictive subgroups, so-called ‘heuristic groups’, can be derived by pooling similar working tasks with similar regression coefficients and enhanced quality measures (adj. R2 between 0.724 and 0.924): ‘welding (grinding time fraction [GTF] 5%)’, ‘high temperature cutting’ and ‘grinding’. For the working activity group ‘high temperature processing’ and the heuristic group ‘welding’ the determination of the grinding time fraction and its inclusion or exclusion from a dataset has a huge impact on the description of data and whether a transformation of nickel concentrations using the natural logarithm (ln) is necessary or not. In case of GTF

Anfang der 1990er-Jahre wurde die Bestimmung des Gesamtmetallgehaltes in der Luft am Arbeitsplatz in Deutschland durch die Einführung einer Aufschlusskonvention mittels offenem Aufschluss in einer Salpetersäure/Salzsäure-Mischung harmonisiert. Inzwischen haben sich Mikrowellen-Druckaufschlussverfahren aufgrund ihrer zahlreichen Vorteile in vielen Bereichen der Spuren- und Ultraspurenanalytik von Metallen als Stand der Technik durchgesetzt. Insbesondere im Hinblick auf stetig steigende Anforderungen an Bestimmungsgrenzen, Probendurchsatz und Arbeitssicherheit empfiehlt es sich, diese Technik als Alternative zum bestehenden Konventionsaufschluss im Arbeitsschutz zu etablieren. Zur Verifizierung eines im IFA entwickelten mikrowellenunterstützten Druckaufschlussverfahrens wurde sowohl ein nationaler Ringversuch mit Mitgliedern der DFG-Arbeitsgruppe „Luftanalysen” (BAuA, IGF, BGN, ALL und VW AG) als auch ein weiterer Ringversuch mit internationalen Arbeitsschutzinstituten (NIOSH, IRSST, ÖSBS, Suva, HSL, WOHL, INRS und STAMI) initiiert. Die statistische Bewertung der zusammengeführten Ergebnisse aus beiden Ringversuchen bestätigt eine gute Vergleichbarkeit zwischen dem Konventionsaufschluss und dem vorgeschlagenen Mikrowellen-Druckaufschlussverfahren.

Die Quantifizierung gesundheitsschädlicher Substanzen an Arbeitsplätzen wurde in den letzten Jahrzehnten immer wichtiger und ist auch weiterhin von großem Interesse. Die Rahmenbedingungen für Gefahrstoffmessungen am Arbeitsplatz haben sich gleichzeitig aufgrund des technischen Fortschritts und fortwährender Grenzwertabsenkungen geändert. Somit ist es essenziell, die analytischen Methoden diesen Änderungen anzupassen. Das Institut für Arbeitsschutz der Deutschen Gesetzlichen Unfallversicherung (IFA) bietet zur Qualitätssicherung für Messstellen verschiedene Ringversuche für gesundheitsschädliche Stoffe am Arbeitsplatz an einer dynamischen Prüfgasstrecke an. Im Zuge kontinuierlicher Verbesserung wurden Online-Messmethoden in den Prozess der Prüfgasherstellung implementiert. Der Einsatz eines Online-Gaschromatographen ermöglicht die selektive Quantifizierung der Substanzen im Prüfgasgemisch und sichert somit die Qualität des Prüfgases, z. B. während der Ringversuche für organische Lösemittel und flüchtige organische Verbindungen.

Exposure to the bicyclic aromatic hydrocarbon naphthalene occurs in most cases along with other polycyclic aromatic hydrocarbons. Here we report from an investigation of 63 healthy, non-smoking male employees in the abrasives industry where naphthalene is the only relevant chemical exposure. Exposure assessment was performed using a combination of Air and Biological Monitoring over nearly a whole working week (Mo.–Th.). Air measurements were carried out during the shift on Thursday with the GGP mini-sampling system, combining particle and vapour sampling at low flow rates. In urine spot samples, the metabolites 1- and 2-naphthol were measured Mo.–Th. pre- and post-shift (for the reference group only Mo. pre- and Th. post-shift). With regard to naphthalene concentrations measured in air and concentrations of its metabolites (1- and 2-naphthol) in urine, study participants could be divided into a high and a low exposure group, and a reference group. The naphthalene concentration in air was in the range of 0.1–11.6 mg m−3, and naphthol concentrations (sum of 1- and 2-naphthol) in post-shift urine were in the range of

Quality control is crucially important in the arena of chemical analysis. Reference materials are essential for calibration and quality control processes, and for verification of the accuracy and reliability of the analytical results obtained. Owing to the complexity of their manufacture, reference materials for chemical agents occurring at workplaces are expensive and available only on a limited scale and for a small number of substances. Therefore, their cost-effective and fast production is an important aim. The Institute for Occupational Health and Safety (IFA) of the German Social Accident Insurance (DGUV) currently pursues different strategies for the production of reference materials. One strategy entails the use of a piezoelectric micro-dispensing system for non-contact spiking of extremely small quantities of substances with high reproducibility. The dispensing system is coupled to a semi-automated assembly unit for loading high numbers of samples. It is used for spiking phosphoric and sulphuric acid onto quartz fibre filters. Comparison of the results obtained on different days shows higher variability than results observed on the same day. However, after daily adjustment of the number of droplets to the current droplet volume, highly reproducible series with an adequate number of samples (>500) could be realized. The results of the internal quality control were verified in an interlaboratory comparison. Furthermore, storage stability was investigated systematically over a period of 2 years. The samples produced are suitable for use as reference materials for both inorganic acids.

In the sector of occupational safety and health only a limited amount of studies are concerned with the conversion of inhalable to respirable dust. This conversion is of high importance for retrospective evaluations of exposure levels or of occupational diseases. For this reason a possibility to convert inhalable into respirable dust is discussed in this study. To determine conversion functions from inhalable to respirable dust fractions, 15 120 parallel measurements in the exposure database MEGA (maintained at the Institute for Occupational Safety and Health of the German Social Accident Insurance) are investigated by regression analysis. For this purpose, the whole data set is split into the influencing factors working activity and material. Inhalable dust is the most important predictor variable and shows an adjusted coefficient of determination of 0.585 (R2 adjusted to sample size). Further improvement of the model is gained, when the data set is split into six working activities and three material groups (e.g. high temperature processing, adj. R2 = 0.668). The combination of these two variables leads to a group of data concerned with high temperature processing with metal, which gives rise to a better description than the whole data set (adj. R2 = 0.706). Although it is not possible to refine these groups further systematically, seven improved groups are formed by trial and error, with adj. R2 between 0.733 and 0.835: soldering, casting (metalworking), welding, high temperature cutting, blasting, chiseling/embossing, and wire drawing. The conversion functions for the seven groups are appropriate candidates for data reconstruction and retrospective exposure assessment. However, this is restricted to a careful analysis of the working conditions. All conversion functions are power functions with exponents between 0.454 and 0.946. Thus, the present data do not support the assumption that respirable and inhalable dust are linearly correlated in general.

Metal occupational exposure limits mainly focus on total content of the respective metals of interest. The methods applied for trace metal analysis in occupational health and safety laboratories are usually standardized to pragmatic consensus digestion schemes, ensuring comparability of results. The objective of the present study entailed the evaluation of a recently developed HNO3-only microwave-assisted digestion procedure by comparison with the German consensus hot-block digestion and other national digestion schemes. An inter-laboratory comparison test with participation of nine national occupational health and safety laboratories from Europe and North America was organized. For adequate emulation of what workers are at risk of inhaling four different industrial metal processing workplace dusts (electronic recycling, high-speed steel grinding, cylinder head cleaning, and battery combustion ash) were homogenized and sieved to the particle size < 100 µm diameter at IFA. The participants were asked to process air sample-typical amounts according to the German hot-plate technique, the IFA microwave-assisted digestion scheme as well as their national or in-house conventional digestion method for airborne dust and analyze for Cd, Co, Cr, Co, Fe, Mg, Ni, Pb, and Zn. Recoveries (relative to consensus open-vessel digestion) obtained for the new IFA microwave-assisted digestion were between 88 and 114% and relative reproducibility standard deviations were

Denuders are gas-particle partitioning tools and can be used in combination with filters and adsorbers for phase-separated collection of hazardous semi-volatile organic compound (SVOC) aerosols. Here, we investigated the suitability of carbonaceous monolithic multi-channel denuders for this approach. Particle transmission efficiency through the denuders was investigated using particles of polystyrene latex (PSL) and droplets of n-hexadecane and diethylene glycol. The time-dependent vapour collection efficiency was analysed for n-hexadecane and diethylene glycol vapours and also compared to calculated predictions. Our measurements showed an averaged transmission efficiency of 97 +/- 4.4% for PSL particles with diameters of 0.51, 0.99, 1.93, and 3.00 mu m. Measurements with one denuder and 1.08, 1.98, and 2.97 mu m particles consisting of n-hexadecane or diethylene glycol resulted in an averaged transmission efficiency of 99 +/- 6.5%. Regarding the vapour collection efficiency at a flow rate of 5 l min(-1), n-hexadecane vapour could be adsorbed to a similar extent (91 +/- 1.4% for one denuder, 98 +/- 0.3% for two denuders) as diethylene glycol vapour (93 +/- 1.8% for one denuder, 97 +/- 0.9% for two denuders). The comparison between experimental and theoretical vapour collection efficiencies revealed differences around 2.8% for n-hexadecane and around 12.3% for diethylene glycol.The results show that the tested denuders can be used as vapour collection tools for SVOCs, and can be integrated in currently used personal air samplers for separated vapour and particle collection.

The sampling of semi volatiles (SV) in workplaces may lead to different results as measurements may be affected by sampling bias. The new European Standard EN 13936 defines "semi-volatiles" as substances with vapour pressures in the range between 0.001 and 100 Pa at room temperature. EN 13936 regulates the basic requirements for SV compounds that can occur as vapour and particle at the same time. Vapour and particles shall not be sampled separately and particles have to be sampled as inhalable fraction. Following EN 13936, the Institute for Occupational Safety and Health (Institut für Arbeitsschutz - IFA) has developed a miniaturized droplet-vapour sampler (GGP-Mini) which is designed to sample the inhalable aerosol fraction at low flow rates. The GGP-Mini uses 13 mm filters for particle sampling combined with adsorption tubes for vapour sampling. Laboratory tests were performed on 11 polar and non-polar compounds in a boiling point range from 188 °C to 318 °C. The substances were spiked directly on the filter followed by aspiration of 40 litres of air. Substances with boiling points below 230 °C were almost completely evaporated. Substances with boiling points above 230 °C up to 300 °C were found on both filter and charcoal tube. Lower-volatile compounds remained almost completely on the filter. For polar substances, the atmospheric humidity had a considerable influence upon the distribution of the liquid and vaporous components. A strong influence of the sampling temperature was found in the range from 0 °C to 50 °C. Droplet-vapour mixtures of n-hexadecane and diethylene glycol with droplet sizes between 1 μm and 4 μm were generated in a flow tube to verify the laboratory results. The aerosol concentrations were analysed on-line with a particle sizer and a flame ionisation detector, while parallel off-line samples were taken with the GGP-Mini. Evaporation losses from filters could be studied by comparing the on-line with off-line measurements. All sampling simulations, both spiking and tests on a droplet aerosol, have shown that the distribution between vapour and droplets is not constant and influenced e. g. by volatility, concentration, temperature and humidity. Only the sum of vapour and droplets constitutes a reproducible result.

Bitumen is classed as possibly carcinogenic to humans according to the International Agency for Research on Cancer. Data on individual exposure to bitumen fumes is therefore required to highlight the exposing situations and develop methods to prevent them. The Institute for Occupational Safety and Health of the German Social Accident Insurance (IFA) and the French National Research and Safety Institute for the Prevention of Occupational Accidents and Diseases (INRS) have both developed methods to measure individual exposure. The objective of this study was to determine a conversion factor to allow interconversion of data acquired by the two methods. To develop this conversion factor, comparative laboratory and workplace tests were performed according to both the IFA method (No. 6305) and the INRS method (MetroPol M-2). The amounts of organic material collected on the filters and XAD-2 beds were compared. The results revealed differences between the sampling and analytical methods that could be linked to sampler design, extraction solvent, and the detection method used. The total quantification returned by the two methods-the sum of the masses quantified on filter and XAD-2 bed for each sampler-were correlated in both controlled and real-life tests. A conversion equation was therefore determined, based on field tests: CIFA = 1.76 CINRS ± 0.39 (R2 = 0.99) that is applicable to total quantification data. This formula can be applied to data acquired by the two institutes to increase the number of data points available on exposure to bitumen fumes in various conditions, and thus increase the statistical power of studies into occupational prevention.

During many measurements it is important to account for possible changes in the gas-particle distribution of aerosols containing semi-volatile organic compounds (SVOCs). If denuders are combined with currently used personal air samplers, a simultaneous differential sampling of the gas and particle phase is possible. Here we analysed the transmission efficiency of denuders based on multi-channel silicone rubber traps (setup: 9 cm long glass liner (ID 4 mm), containing 22 parallel silicone rubber tubes (55 mm long, ID 0.3 mm, OD 0.5 mm)) with polystyrene latex (PSL) particles for different scenarios. n-Hexadecane, dimethyl phthalate and diethylene glycol gases were used to measure the time-dependent gas phase collection efficiency of a denuder. Additionally, the evaporation of n-hexadecane aerosol particles passing through the denuders was investigated. Our results showed high transmission efficiencies from 91 to 100% (variation coefficients 3.69-9.65%) for the denuders operated vertically at a flow rate of 0.5 l min(-1). With regard to the gas phase collection efficiency, nonpolar n-hexadecane gas was trapped with higher efficiency (87% after 22 h) than dimethyl phthalate gas (27% after 22 h), while for highly polar diethylene glycol the gas phase collection efficiency was 50% after 2 h. Regarding the evaporation of aerosol particles, smaller particles and lower flow rates led to higher particle volume reduction inside the denuders. In conclusion, the tested denuders are suitable for determining the gas-particle partitioning of SVOC aerosols of nonpolar substances and show above 90% transmission for all tested particle sizes.

Acid gases/vapors and aerosols are highly corrosive and can irritate the eyes and mucous membranes of the nose, pharynx and respiratory tract, even at low airborne concentrations. Hydrofluoric acid (HF), hydrochloric acid (HCl), nitric acid (HNO3), hydrobromic acid (HBr), sulfuric acid (H2SO4) and phosphoric acid (H3PO4) are used widely in industrial processes such as ore extraction, metal processing, pickling, electroplating and myriad other chemical processes. It is common for several of these acids to occur simultaneously in the air of occupational settings. Applicable occupational exposure limits (OELs) for these substances in air generally range between 0.1–10 mg/m3 for the various acids.(1) The physical states of the different acids in workplace atmospheres may vary from liquid aerosols (mists) for nonvolatile acids like H2SO4 to gases/vapors for volatile acids such as HCl or HNO3. Procedures for sampling and analyzing inorganic acids in workplace air must take into account the physical state(s) of the target analyte(s). Hence new NIOSH methods for sampling and analysis of inorganic acids in workplace atmospheres, methods 7906, 7907 and 7908,(2) have been promulgated to account for the collection of inorganic acid gases/vapors and/or aerosols. The technical contents of these new NIOSH methods are based on related recently-developed International Organization for Standardization (ISO) consensus standards.(3)

Workplace measurements are intended to give information about kind and extent of workers' exposure during their activities with hazardous substances. For this purpose calibration is necessary to establish the relationship between a known concentration and the corresponding measuring signal resulting in reliable measuring results at a high level of quality. Therefore, calibration strongly influences accuracy and precision of the whole measuring procedure. Calibration is required for different tasks. During development of a measurement procedure the calibration range has to be determined, for which there must be a linear relationship between the concentration of the analyte and the response of the analytical procedure. Important analytical parameters such as limit of detection (LOD) and limit of quantification (LOQ) may also be determined using calibration procedures. Normally, calibration is needed for the quantification of hazardous substances from workplace measurements. In this case the composition of calibration solutions should be as near as possible to that of the collected samples. The calibrated concentration range should yield unambiguous analytical results. Traceability of the complete calibration procedure from the measuring result back to the typically used (certified) reference material must be ensured. This chapter describes how to perform calibration for different purposes and the possible sources of errors which have to be considered. Requirements for reference materials are also specified. Joint Publication of the Analytical Subcommittee of the Chemistry Board of Experts of the Expert Committee Raw Materials and Chemical Industry of the German Social Accident Insurance and the Working Group “Air Monitoring Methods” of the Permanent Senate Commission of the DFG for the Investigation of Health Hazards of Chemical Compounds in the Work Area. Keywords: calibration; reference materials; calibration standards; calibration function; air analysis; workplace measurement; hazardous substances; workplace monitoring; air sampling

We first describe the implantation of a MitraClip (Abbott Vascular, Abbott Park, IL, USA) between 2 previously implanted MitraClips to treat recurrent mitral regurgitation (MR). An 82-year-old male patient presented with dyspnea New York Heart Association NYHA class III due to recurrent severe MR 18 months after primarily successful implantation of 2 MitraClips. The initial procedure was performed to treat severe MR due to prolapse and flail of the anterior leaflet and resulted in mild MR after implantation of 2 MitraClips. Concomitant diseases were persistent atrial fibrillation, moderate tricuspid valve regurgitation, and chronic kidney disease stage 3. Thus, the patient was not considered a suitable candidate for surgical treatment. Using fluoroscopic guidance, 2D- and 3D-transesophageal echocardiographies, we succeeded in placing a third clip between the previously implanted clips and reduced the severe MR to mild MR without increase in the mean gradient. No periprocedural complications were observed. Six months after the procedure the patient presented with mild MR and NYHA class I. Learning objective: Implantation of MitraClips offers the possibility of percutaneous mitral valve repair. It is feasible, safe, and effective to implant a 3rd MitraClip between 2 previously implanted MitraClips to treat recurrent mitral regurgitation between the clips.>

This analytical method is a validated measurement procedure for the determination of gaseous N-methyl-2-pyrrolidone (NMP) and N-ethyl-2-pyrrolidone (NEP) and for monitoring their Occupational Exposure Limits (OELs) or MAK values at workplaces. Both personal and stationary sampling can be performed for assessment of workplaces. Sampling is carried out by drawing air through a silica gel tube spiked with d9-NMP as internal standard using a suitable flow-regulated pump. The flow rate is set to approx. 0.33 L/min with a recommended air sample volume of 40 litres. For sample preparation the collected NMP and/or NEP are desorbed from the silica gel with methanol. The sample solutions are analysed by means of gas chromatography-mass spectrometry (GC-MS). The quantitative determination is based on calibration functions obtained by means of multiple-point calibrations. The limit of quantification is 0.15 mg/m3 for NMP and 0.3 mg/m3 for NEP with an expanded uncertainty of approx. 20%. Keywords: N-methyl-2-pyrrolidone; N-ethyl-2-pyrrolidone; NMP; NEP; air analysis; workplace measurement; hazardous substances; workplace monitoring; measurement method; measuring procedure; gas chromatography; mass spectrometry; GC-MS; adsorption tube; silica gel; personal sampling

In the December 2010 article, Table II was published with several errors, and Table IV included only 19 of 29 data points. The corrected tables follow: Site Location/DateDescriptionSampling Time (h...

Historically, workplace exposure to the volatile inorganic acids hydrochloric acid (HCl) and nitric acid (HNO3) has been determined mostly by collection on silica gel sorbent tubes and analysis of the corresponding anions by ion chromatography (IC). However, HCl and HNO3 can be present in workplace air in the form of mist as well as vapor, so it is important to sample the inhalable fraction of airborne particles. As sorbent tubes exhibit a low sampling efficiency for inhalable particles, a more suitable method was required. This is the first of two articles on “Evaluation of Sampling Methods for Measuring Exposure to Volatile Inorganic Acids in Workplace Air” and describes collaborative sampling exercises carried out to evaluate an alternative method for sampling HCl and HNO3 using sodium carbonate-impregnated filters. The second article describes sampling capacity and breakthrough tests. The method was found to perform well and a quartz fiber filter impregnated with 500 μL of 1 M Na2CO3 (10% (m/v) Na2CO3...

To study the associations between exposure to vapours and aerosols of bitumen and genotoxic effects, a cross-sectional and cross-shift study was conducted in 320 exposed workers and 118 non-exposed construction workers. Ambient air measurements were carried out to assess external exposure to vapours and aerosols of bitumen. Hydroxylated metabolites of naphthalene, phenanthrene and pyrene were measured in urine, whereas (+)-anti-benzo[a]pyrene-7,8-diol-9,10-epoxide ((+)-anti-BPDE), 8-oxo-7,8-dihydro-2'-deoxyguanosine (8oxodGuo) and DNA strand breaks were determined in blood. Significantly higher levels of 8-oxodGuo adducts and DNA strand breaks were found in both pre- and post-shift blood samples of exposed workers compared to those of the referents. No differences between exposed workers and referents were observed for (+)-anti-BPDE. Moreover, no positive associations between DNA damage and magnitude of airborne exposure to vapours and aerosols of bitumen could be observed in our study. Additionally, no relevant association between the urinary metabolites of PAH and the DNA damage in blood was observed. Overall, our results indicate increased oxidative DNA damage in workers exposed to vapours and aerosols of bitumen compared to non-exposed referents at the group level. However, increased DNA strand breaks in bitumen workers were still within the range of those found in non-exposed and healthy persons as reported earlier. Due to the lack of an association between oxidative DNA damage and exposure levels at the workplaces under study, the observed increase in genotoxic effects in bitumen workers cannot be attributed to vapours and aerosols of bitumen.

The chemical complexity of emissions from bitumen applications is a challenge in the assessment of exposure. Personal sampling of vapours and aerosols of bitumen was organized in 320 bitumen-exposed workers and 69 non-exposed construction workers during 2001-2008. Area sampling was conducted at 44 construction sites. Area and personal sampling of vapours and aerosols of bitumen showed similar concentrations between 5 and 10 mg/m(3), while area sampling yielded higher concentrations above the former occupational exposure limit (OEL) of 10 mg/m(3). The median concentration of personal bitumen exposure was 3.46 mg/m(3) (inter-quartile range 1.80-5.90 mg/m(3)). Only few workers were exposed above the former OEL. The specificity of the method measuring C-H stretch vibration is limited. This accounts for a median background level of 0.20 mg/m³ in non-exposed workers which is likely due to ubiquitous aliphatic hydrocarbons. Further, area measurements of polycyclic aromatic hydrocarbons (PAHs) were taken at 25 construction sites. U.S. EPA PAHs were determined with GC/MS, with the result of a median concentration of 2.47 μg/m(3) at 15 mastic asphalt worksites associated with vapours and aerosols of bitumen, with a Spearman correlation coefficient of 0.45 (95% CI -0.13 to 0.78). PAH exposure at mastic-asphalt works was higher than at reference worksites (median 0.21 μg/m(3)), but about one order of magnitude lower compared to coke-oven works. For a comparison of concentrations of vapours and aerosols of bitumen and PAHs in asphalt works, differences in sampling and analytical methods must to be taken into account.

Bitumen (referred to as asphalt in the United States) is a widely used construction material, and emissions from hot bitumen applications have been a long-standing health concern. One objective of the Human Bitumen Study was to identify potential determinants of the exposure to bitumen. The study population analysed comprised 259 male mastic asphalt workers recruited between 2003 and 2008. Personal air sampling in the workers' breathing zone was carried out during the shift to measure exposure to vapours and aerosols of bitumen. The majority of workers were engaged in building construction, where exposure levels were lower than in tunnels but higher than at road construction sites. At building construction sites, exposure levels were influenced by the room size, the processing temperature of the mastic asphalt and the job task. The results show that protective measures should include a reduction in the processing temperature.

Standardization is essential to fostering the use of harmonized methods for exposure assessment in occupational hygiene nationally and internationally. A standardized method for sampling and analys...

Mastic asphalt workers may be exposed to polycyclic aromatic hydrocarbons (PAH) present in bitumen. We conducted a cross-shift study to determine genotoxic effects after exposure to bitumen. For this purpose, external and internal exposure of 202 mastic asphalt workers exposed to bitumen and 55 construction workers without exposure to bitumen was assessed. Exposure by inhalation to fumes of bitumen during the shift was measured by personal ambient monitoring. To assess overall exposure to bitumen (by inhalation and dermal absorption), 1-hydroxypyrene (1-OHP) and the sum of 1-, 2 + 9-,3-,4-hydroxyphenanthrene (OHPhe) were determined in pre- and postshift urine. 8-Oxo-7,8-dihydro-2′-deoxyguanosine (8-oxodGuo) adducts, anti-benzo[a]pyrene-7,8-diol-9,10-epoxide (anti-BPDE) DNA adducts, DNA strand breaks and alkali-labile sites, and micronucleus frequencies were determined as biomarkers of genotoxic effects in white blood cells (WBC). Concentrations of fumes of bitumen were correlated with a moderate associati...