Journal of Occupational Health
Online ISSN : 1348-9585
Print ISSN : 1341-9145
ISSN-L : 1341-9145
Volume 51, Issue 6
Displaying 1-9 of 9 articles from this issue
Original
  • Yonghui Wu, Zhongyi Zhang, Baoqi Gang, Edgar J. Love
    Article type: Original
    2009 Volume 51 Issue 6 Pages 471-477
    Published: 2009
    Released on J-STAGE: December 18, 2009
    Advance online publication: September 25, 2009
    JOURNAL FREE ACCESS
    Objectives: The currently used predictive equations of lung function in North China were derived from early study and have not been updated for nearly two decades. Methods: Using American Thoracic Society (ATS) standards, sex-specific spirometric predictive equations for forced vital capacity (FVC), forced expiratory volume in one second (FEV1), ratio of FEV1 to FVC (FEV1%) and forced expiratory flow at 25-75% of forced vital capacity (FEF25-75%) were derived from 2,897 asymptomatic, lifelong non-smokers (1,208 males, 1,689 females) from a large occupational population in North China. Stepwise multiple regressions were carried out to identify the best predictors of lung function parameters and predictive equations. Independent variables considered for inclusion in predictive equations including age, height, weight and chest circumference were examined. Results: Age and height were found to be necessary variables for all lung function parameters. Weight was a significant variable in only half of our equations. Chest circumferences (expired or inspired) was excluded as they are not practical in use. Data from 255 apparently healthy non-smokers were used to validate the equations by comparing percentage predicted values and proportion of subjects with normal predicted values with those from the study group, and a high accordance was obtained. Other equations published and used in North China do not appear to offer advantages over these equations. Conclusions: These newly developed predictive equations should ideally be applied to calculate lung function for adult individuals and populations as reference values in North China.
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  • Ai Okamura, Michihiro Kamijima, Katsumi Ohtani, Osamu Yamanoshita, Dai ...
    Article type: Original
    2009 Volume 51 Issue 6 Pages 478-487
    Published: 2009
    Released on J-STAGE: December 18, 2009
    Advance online publication: September 25, 2009
    JOURNAL FREE ACCESS
    Objectives: Recent reports have shown significant associations between organopshophorus pesticide (OP) exposure and decreased sperm motility in workers and laboratory animals. However, the notion that OPs possess spermatotoxicity has yet to be established. The aim of this study was to clarify the effects of OP exposure on detailed sperm toxicity markers, i.e., motility, morphology and sperm adenine nucleotide contents, and the histopathology of the testis and epididymis. Methods: Ten-week-old Wistar rats were divided into 4 groups (n=10) and orally administered corn oil, dichlorvos (DDVP; 5, 10 mg/kg) or diazinon (DZN; 3 mg/kg) 6 days a week for 9 wk. Sperm motility and morphology markers were analyzed with a computer-assisted sperm analysis (CASA) system. Results: In addition to a significant decrease in acetylcholinesterase (AChE) activities and a significant increase in urinary OP metabolites, DDVP and DZN significantly reduced sperm motility, but they did not influence sperm adenine nucleotide contents. The OPs also significantly increased the percentage of broken sperm, and DDVP significantly increased the percentage of cytoplasmic droplets. Importantly, both OPs significantly increased cytoplasmic vacuolation and nuclear shrinkage in the epithelial cells of the ductus epididymis, whereas the testes did not show significant histopathological changes. Conclusions: The broken sperm and cytoplasmic droplets as well as reduced sperm motility were the relevant spermatotoxicity makers of DDVP and DZN. To our knowledge, this is the first report to suggest that the above-mentioned OP-induced spermatotoxicity is related to histopathological impairment of the caput epididymis.
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  • Sreeparna Chakraborty, Sayali Mukherjee, Sanghita Roychoudhury, Shaban ...
    Article type: Original
    2009 Volume 51 Issue 6 Pages 488-497
    Published: 2009
    Released on J-STAGE: December 18, 2009
    Advance online publication: October 23, 2009
    JOURNAL FREE ACCESS
    Objective: The impact of long term exposure to cholinesterase (ChE)-inhibiting organophosphate (OP) and carbamate (C) pesticides on the respiratory health of agricultural workers in India was investigated. Methods: Three hundred and seventy-six nonsmoking agricultural workers (median age 41 yr) from eastern India who sprayed OP and C pesticides in the field and 348 age- and sex-matched control subjects with non-agricultural occupations from the same locality were enrolled. Prevalence of respiratory symptoms was obtained by questionnaire survey, and pulmonary function tests were carried out by spirometry. Chronic obstructive pulmonary disease (COPD) was diagnosed by the Global Obstructive Lung Disease (GOLD) criteria, and erythrocyte acetylcholinesterase (AChE) was measured by the Ellman method. Results: Agricultural workers had greater prevalences of upper and lower respiratory symptoms, and appreciable reduction in spirometric measurements. Overall, lung function reduction was noted in 48.9% of agricultural workers compared with 22.7% of control, and a restrictive type of deficit was predominant. COPD was diagnosed in 10.9% of agricultural workers compared with 3.4% of controls (p<0.05 in χ2 test), and the severity of the disease was greater in agricultural workers. Red blood cell (RBC) AChE was lowered by 34.2% in agricultural workers, and the fall in AChE level was positively associated with respiratory symptoms, lung function decrement and COPD after controlling for education and income as potential confounders. Conclusions: Long-term exposure to cholinesterase-inhibiting agricultural pesticides currently in use in India is associated with a reduction in lung function, COPD and a rise in respiratory symptoms.
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  • Keiko Asakura, Hiroshi Satoh, Momoko Chiba, Masahide Okamoto, Koji Ser ...
    Article type: Original
    2009 Volume 51 Issue 6 Pages 498-512
    Published: 2009
    Released on J-STAGE: December 18, 2009
    Advance online publication: October 23, 2009
    JOURNAL FREE ACCESS
    Objectives: Many kinds of heavy metals are used in industry; thus, it is important for us to clarify their toxicity. For example, lead, which is a component of solder, is notorious for its neurotoxicity, and substitute materials have been sought for many years. Therefore, we examined the genotoxicity of lead and also those of metallic bismuth, indium, silver and antimony which are possible substitutes for lead in solder. Methods: Bacterial reverse mutation tests and chromosomal aberration tests in cultured mammalian cells were performed according to standard procedures. Results: Antimony showed genotoxicity in both tests, and bismuth also showed positive results in the chromosomal aberration test. In contrast, lead, indium, and silver were considered to be inactive by the criteria of the present study. Conclusions: Although further studies are needed because of the difficulty of genotoxicity evaluation using an in vitro system, sufficient precautions should be made when antimony and bismuth are used.
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  • Makiko Nakano, Kazuyuki Omae, Akiyo Tanaka, Miyuki Hirata, Takehiro Mi ...
    Article type: Original
    2009 Volume 51 Issue 6 Pages 513-521
    Published: 2009
    Released on J-STAGE: December 18, 2009
    Advance online publication: October 16, 2009
    JOURNAL FREE ACCESS
    Background: Recent case reports and epidemiological studies suggest that inhalation of indium dust induces lung damage. Objectives: To elucidate the dose-dependent effects of indium on the lungs and to prove a causal relationship more clearly. Methods: A baseline observation was conducted on 465 workers currently exposed to indium, 127 workers formerly exposed to indium and 169 workers without indium exposure in 12 factories and 1 research laboratory from 2003 to 2006. Indium in serum (In-S) was determined as an exposure parameter, and its effects on the lungs were examined. Results: The means of In-S in the current, former and no exposure workers were 8.35, 9.63 and 0.56 ng/ml, respectively. The current and former exposure workers had significantly higher levels of KL-6, and showed significant dose-dependent increases in KL-6, SP-D, and SP-A. Current exposure workers with In-S of 3 ng/ml or above demonstrated a significant increase of KL-6 in both GM and prevalence exceeding the reference value. Approximately a quarter of the former exposure workers had interstitial changes as seen on chest HRCT. In-S of exposed workers who had been working before improvements of the working environment (Group Bef) and those who started working after improvements (Group Aft) were 12.29 and 0.81 ng/ml, respectively. Adjusted odds ratios indicated 87%, 71% and 44% reductions among Group Aft workers who exceeded the reference values of KL-6, SP-D and SP-A, respectively. Conclusion: Dose-dependent lung effects due to indium exposure were shown, and a decrease of indium exposure reduced the lung effects. An In-S value of 3 ng/ml may be a cut-off value which could be used to prevent early effects on the lungs.
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