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Articles by Hakan Tinnerberg
Total Records ( 3 ) for Hakan Tinnerberg
  Hakan Tinnerberg and Christian Mattsson
  Exposure to isocyanates is known to have respiratory effects in workers and therefore it is essential to monitor the occupational exposure. An earlier study of a continuous foaming plant using toluene diisocyanate (TDI) showed that the exposure to isocyanates can be high. Since then several preventive actions were implemented at the plant. The aim of this study was to observe the effect of these actions measured by air and biological monitoring. Four workers were monitored in the year 2000 and six in 2005, with air measurements during the continuous foaming process, and with measurements of biomarkers in one plasma sample each year and with two urinary samples being collected in the year 2000 and one in 2005. The median TDI air concentrations in 2005 were ~20% of the 2000 levels and the median levels of biomarkers in 2005 were ~10% of the 2000 levels. According to our measurements the preventive action had a real effect to decrease the exposure to TDI. As the workers both before and after the preventive actions used personal protective equipment, the use of biomarkers was necessary to assess the real gain in the preventive actions.
  Elsebeth Lynge , Hakan Tinnerberg , Lars Rylander , Pal Romundstad , Kristina Johansen , Marja-Liisa Lindbohm , Pirjo Heikkila , Hakan Westberg , Lene Bjork Clausen , Antoine Piombino and Brian Larsen Thorsted
  Objectives: Tetrachloroethylene is the dominant solvent used in dry cleaning worldwide and many workers are potentially exposed. We report here on results of 1296 measurements of tetrachloroethylene undertaken in Nordic dry cleaning shops 1947-2001.

Methods: We searched documents and files in the Nordic institutes of occupational health for air measurements of tetrachloroethylene. Repeated measurements from the same facility during a short time interval were registered only once using the time-weighted average. We registered also changes over time in occupational exposure limits (OELs) to tetrachloroethylene.

Results: Only scattered measurements were available from the early years, and the exposure level seemed fairly stable up until the mid 1970s. The median exposure level was 20 p.p.m. in 1976 and decreased to 3 p.p.m. in 2000. Exposure levels in the four Nordic countries followed similar trends. In the late 1960s, the OELs varied between the Nordic countries from 30 to 100 p.p.m. Sweden was first to lower the limit, but limits gradually converged over time. At present, Denmark, Finland, and Sweden use 10 p.p.m., while Norway uses 6 p.p.m. Over time, the average observed exposure level was lower than the OEL in all countries, but in Denmark and Sweden, up to one-third of measured exposures exceeded the OEL. Overall, the stationary measurements for maintenance work showed 36 p.p.m., while the personal measurements showed 7.5 p.p.m. for dry cleaners and 6.25 p.p.m. for shop assistants.

Conclusion: The Nordic data illustrate that it is possible over time to control chemical exposures even in an industry consisting of many small and scattered work places.

  Maria Hedmer , Christina Isaxon , Patrik T. Nilsson , Linus Ludvigsson , Maria E. Messing , Johan Genberg , Vidar Skaug , Mats Bohgard , Hakan Tinnerberg and Joakim H. Pagels
  Background: The production and use of carbon nanotubes (CNTs) is rapidly growing. With increased production, there is potential that the number of occupational exposed workers will rapidly increase. Toxicological studies on rats have shown effects in the lungs, e.g. inflammation, granuloma formation, and fibrosis after repeated inhalation exposure to some forms of multi-walled CNTs (MWCNTs). Still, when it comes to health effects, it is unknown which dose metric is most relevant. Limited exposure data for CNTs exist today and no legally enforced occupational exposure limits are yet established. The aim of this work was to quantify the occupational exposures and emissions during arc discharge production, purification, and functionalization of MWCNTs. The CNT material handled typically had a mean length <5 μm. Since most of the collected airborne CNTs did not fulfil the World Health Organization fibre dimensions (79% of the counted CNT-containing particles) and since no microscopy-based method for counting of CNTs exists, we decided to count all particle that contained CNTs. To investigate correlations between the used exposure metrics, Pearson correlation coefficient was used.

Methods: Exposure measurements were performed at a small-scale producer of MWCNTs and respirable fractions of dust concentrations, elemental carbon (EC) concentrations, and number concentrations of CNT-containing particles were measured in the workers’ breathing zones with filter-based methods during work. Additionally, emission measurements near the source were carried out during different work tasks. Respirable dust was gravimetrically determined; EC was analysed with thermal-optical analysis and the number of CNT-containing particles was analysed with scanning electron microscopy.

Results: For the personal exposure measurements, respirable dust ranged between <73 and 93 μg m-3, EC ranged between <0.08 and 7.4 μg C m-3, and number concentration of CNT-containing particles ranged between 0.04 and 2.0cm-3. For the emission measurements, respirable dust ranged between <2800 and 6800 μg m-3, EC ranged between 0.05 and 550 μg C m-3, and number concentration of CNT-containing particles ranged between <0.20 and 11cm-3.

Conclusions: The highest exposure to CNTs occurred during production of CNTs. The highest emitted number concentration of CNT-containing particles occurred in the sieving, mechanical work-up, pouring, weighing, and packaging of CNT powder during the production stage. To be able to quantify exposures and emissions of CNTs, a selective and sensitive method is needed. Limitations with measuring EC and respirable dust are that these exposure metrics do not measure CNTs specifically. Only filter-based methods with electron microscopy analysis are, to date, selective and sensitive enough. This study showed that counting of CNT-containing particles is the method that fulfils those criteria and is therefore the method recommended for future quantification of CNT exposures. However, CNTs could be highly toxic not only because of their length but also because they could contain, for example transition metals and polycyclic aromatic hydrocarbons, or have surface defects. Lack of standardized counting criteria for CNTs to be applied at the electron microscopy analysis is a limiting factor, which makes it difficult to compare exposure data from different studies.

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