Journal of Occupational Health
Online ISSN : 1348-9585
Print ISSN : 1341-9145
ISSN-L : 1341-9145
Volume 52, Issue 3
Displaying 1-6 of 6 articles from this issue
Original
  • Betina Holbæk Pedersen, Harald Hannerz, Finn Tüchsen, Kim L ...
    Article type: Original
    2010 Volume 52 Issue 3 Pages 147-154
    Published: 2010
    Released on J-STAGE: June 08, 2010
    Advance online publication: March 19, 2010
    JOURNAL FREE ACCESS
    Objectives: To estimate proportions of injuries that are attributable to the work environment (excess fractions) among economically active men and to identify industries associated with an elevated injury risk. Methods: A follow-up study was conducted among all economically active men in Denmark aged 20-59 yr 1 January 1999 (N=1,315,772) for first hospital contacts in the period 1999-2003 due to injury in five body regions. Age standardised hospital treatment ratios (SHR) were calculated by industry and excess fractions were estimated. Results: The excess fractions by body region attributable to the work environment were: 22% (95% CI 18-26%) for lower extremities, 29% (95% CI 24-34%) for head and neck, 31% (95% CI 25-37%) for thorax, 36% (95% CI 30-43%) for upper extremities, and 39% (CI: 32-46%) for back injuries. We identified eight industries associated with significantly elevated risks for injuries to each of the five body regions. These were: "road contractors", "bricklayer, joiner, and carpentry work", "finishing (construction work)", "transport of goods", "fire service and salvage corps", "stone-works, pottery, and glass industry", "cleaning, laundries, and dry cleaners", and "slaughterhouse industry". Conclusions: There are substantial industrial inequalities in injury rates among male workers in Denmark. The size of the inequalities differs between body regions.
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  • Masumi Asakura, Toshiaki Sasaki, Toshie Sugiyama, Mitsutoshi Takaya, S ...
    Article type: Original
    2010 Volume 52 Issue 3 Pages 155-166
    Published: 2010
    Released on J-STAGE: June 08, 2010
    Advance online publication: April 02, 2010
    JOURNAL FREE ACCESS
    Objectives: The potential applications and industrial production of multi-wall carbon nanotubes (MWCNT) have raised serious concerns about their safety for human health and the environment. The present study was designed to examine the in vitro cytotoxicity and genotoxicity of MWCNT and UICC chrysotile A (chrysotile). Methods: Cytotoxicity using both colony formation and lactate dehydrogenase (LDH) assays and genotoxicity including chromosome aberration, micronucleus induction and hgprt mutagenicity were examined by exposing cultured Chinese hamster lung (CHL/IU) cells to MWCNT or chrysotile at different concentrations. Results: The in vitro cytotoxicity of MWCNT depended on the solvent used for suspension of MWCNT and ultrasonication duration of the MWCNT suspension. A combination of DMSO/culture medium and 3-minute ultrasonication resulted in a well-dispersed medium with dispersion and isolation of agglomerated MWCNT by ultrasonication which manifested the highest cytotoxicity. The cytotoxicity was more potent for chrysotile than MWCNT. The genotoxicity of MWCNT was characterized by the formation of polyploidy without structural chromosome aberration, and an increased number of bi- and multi-nucleated cells without micronucleus induction, as well as negative hgprt mutagenicity. Chrysotile exhibited essentially the same genotoxicity as MWCNT, except for marginal but significant induction of micronuclei. MWCNT and chrysotile were incompletely internalized in the cells and localized in the cytoplasm. Conclusions: MWCNT and chrysotile were cytotoxic and genotoxic in Chinese hamster lung cells, but might interact indirectly with DNA. The results suggest that both test substances interfere physically with biological processes during cytokinesis.
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  • Chikage Nagano, Takao Tsutsui, Koichi Monji, Yasuhiro Sogabe, Nozomi I ...
    Article type: Original
    2010 Volume 52 Issue 3 Pages 167-175
    Published: 2010
    Released on J-STAGE: June 08, 2010
    Advance online publication: April 05, 2010
    JOURNAL FREE ACCESS
    Objectives: Measuring core body temperature is crucial for preventing heat stress disorders in workers. We developed a method for measuring auditory canal temperatures based on a thermocouple inserted into a sponge-type earplug. We verified that the tip of this thermocouple is positioned safely, allowing the wearer to engage in normal physical tasks; this position averaged 6.6 mm from the tympanic membrane. Methods: To assess this technique, we had six healthy male students repeat three cycles of exercise and rest (20 min of exercise and 15 min of rest) in a temperature-controlled chamber with temperatures set at 25, 30, or 35°C, while monitoring the auditory canal, esophageal, rectal, and skin temperatures. Results: We observed differences of a mere 0.30-0.45°C between rectal temperatures and auditory canal temperatures measured with the thermocouple, the smallest such difference reported to date in studies involving auditory canal temperature measurement. Conclusions: We conclude that monitoring temperatures based on a technique involving an auditory canal plug can be used to estimate rectal temperatures accurately, and thereby to avoid conditions leading to heat stress disorders.
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  • Alain Marchand, Marie-Eve Blanc
    Article type: Original
    2010 Volume 52 Issue 3 Pages 176-185
    Published: 2010
    Released on J-STAGE: June 08, 2010
    Advance online publication: April 09, 2010
    JOURNAL FREE ACCESS
    Objectives: This study examined how occupation and work organization conditions contributed, over 8 yr, to the onset of psychological distress after adjusting for non-work and individual characteristics. Methods: The data came from the five cycles (Cycle 1=1994-1995, Cycle 5=2002-2003) of Statistics Canada's National Population Health Survey. A sample of 5,270 workers nested in 1,122 neighborhoods and aged 15 to 55 yr with no psychological distress at baseline was analyzed with discrete time survival multilevel regression models. Results: The onset of psychological distress decreased over time. Occupation was not significant, whereas social support at work decreased the risk. Substantial effects for non-work and individual factors were found, including neighborhood, social support outside the workplace, demographics, physical health, personality traits, and life habits. Conclusions: This study found that work characteristics made a limited contribution to the onset of psychological distress, but social support in the workplace clearly proved to be an important protective factor. Enterprises must pay special attention to how colleagues and supervisors act to help workers complete tasks.
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Field Study
  • Tamami Kawasaki, Takashi Kyotani, Tomoyoshi Ushiogi, Yasuhiko Izumi, H ...
    Article type: Field Study
    2010 Volume 52 Issue 3 Pages 186-193
    Published: 2010
    Released on J-STAGE: June 08, 2010
    Advance online publication: March 19, 2010
    JOURNAL FREE ACCESS
    Objectives: The current study was performed to (1) understand the distribution of airborne fungi culturable on dichloran-glycerol agar (DG18) media over a one-year monitoring period, (2) identify the types of airborne fungi collected, and (3) compare and contrast under- and above-ground spaces, in two railway stations in Tokyo, Japan. Methods: Measurements of airborne fungi were taken at stations A and B located in Tokyo. Station A had under- and above-ground concourses and platforms whereas station B had spaces only above-ground. Airborne fungi at each measurement position were collected with an air sampler on DG18 media. After cultivation of the sample plates, the number of fungi colonies was counted on each agar plate. Results: In station A, the underground platform was characterized as (1) having the highest humidity and (2) a high concentration of airborne fungi, with (3) a high proportion of non-sporulating fungi (NSF) and Aspergillus versicolor. There was a strong positive correlation between the concentrations of airborne particles and fungi in station A. Common aspects of the two stations were (1) that fungi were mostly detected in autumn, and (2) there was no correlation between the humidity and concentration of fungi throughout the year. Conclusions: The results of this study indicate that the distribution and composition of fungi differ depending on the structure of the station.
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Brief Report
  • Akito Takeuchi, Yasuki Nishimura, Yuichiro Kaifuku, Tsutoshi Imanaka, ...
    Article type: Brief Report
    2010 Volume 52 Issue 3 Pages 194-197
    Published: 2010
    Released on J-STAGE: June 08, 2010
    Advance online publication: April 02, 2010
    JOURNAL FREE ACCESS
    Objectives: The purpose of this research was to develop a determination method for nitromethane (NM) in workplace air for risk assessment. Methods: A suitable sampler and appropriate desorption condition were selected by a recovery test in which a spiked sampler was used. The characteristics of the proposed method, such as recovery, detection limit, and reproducibility, and the storage stability of the sample were examined. Results: A sampling tube containing bead-shaped activated carbon was chosen as the sampler. NM in the sampler was desorbed with acetone and analyzed by a gas chromatograph equipped with a flame ionization detector. The recoveries of NM from the spiked sampler were 81-97% and 80-98% for personal exposure monitoring and working environment measurement, respectively. On the first day of storage in a refrigerator, the recovery from the spiked samplers exceeded 90%; however, it decreased dramatically with increasing storage time. In particular, the decrease was more remarkable for the smaller spiked amounts. The overall LOQ was 2 μg/sample. The relative standard deviation, which represents the overall reproducibility, was 1.1-4.0%. Conclusions: The proposed method enables 4-hour personal exposure monitoring of NM at concentrations equaling 0.001-2 times the threshold limit value-time-weighted average (TLV-TWA: 20 ppm) proposed by the American Conference of Governmental Industrial Hygienists, as well as 10-minute working environment measurement at concentrations equaling 0.02-2 times TLV-TWA. Thus, the proposed method will be useful for estimating worker exposure to NM.
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