Biomedical subjects

Ippei Mori

Publications and source records attributed to Ippei Mori.

9 recordsLinked to original sources

PubMed2006

Inverse relationship between serum erythropoietin and blood lead concentrations in Kathmandu tricycle taxi drivers.

OBJECTIVE: Kathmandu tricycle taxi drivers, whose environmental lead (Pb) exposure is ascribable mainly to vehicular exhaust, were studied to examine a dose-response relationship between blood Pb (Pb-B) and serum erythropoietin (sEPO) concentrations. METHODS: Subjects were 27 drivers and 9 non-drivers. They were non-anemic healthy men with normal renal function. Pb-B was measured by an atomic absorption spectrometer with a graphite furnace, and sEPO was determined with a sandwich-type enzyme-linked immunosorbent assay. RESULTS: sEPO levels in drivers were lower than those of non-drivers, while Pb-B levels in drivers were higher than those of non-drivers. There was an inverse relationship between Pb-B and sEPO. CONCLUSIONS: The data suggest that Pb inhibits renal EPO production in a dose-dependent manner in persons with subclinical Pb toxicity. sEPO may serve as an early biochemical marker of subclinical Pb toxicity.

Adolescent↗

PubMed2006

[VDT worker's posture and workload in free-address office system].

A free-address system is a new office layout in which a worker can freely sit in their favorite place with a computer and materials. Since this layout has recently been introduced in offices, we conducted a questionnaire survey which aimed to clarify the effects of the free-address system on visual display terminals (VDT) workers' posture and workload. A total of 203 male VDT workers who were system engineers aged 20 to 59 using a notebook computer were evaluated, of whom 150 used the free-address layout, and 53 used the fixed-address layout. The free-address layout was effective in the improvement of individual work space compared with the fixed-address layout. Also, in this layout the worker did not feel dissatisfaction with communication or support between workers. However, workers using the free-address layout assumed an unsuitable work posture, without adjusting the height of their chairs. Furthermore, this layout might have risk factors which increase neck/shoulder and low back stiffness and/or pain. Therefore, the free-address layout may have incipient problems, and it will be necessary to examine further the effects of this layout on VDT worker's health.

Adult↗

PubMed2006

Relationship between blood lead level and work related factors using the NIIH questionnaire system.

Over an 11-yr period (1990-2000), a questionnaire survey on work environmental management and environmental improvement was conducted on 259 lead-handling factories and 7,623 subjects. Labour Inspection Offices identified these factories as requiring environmental improvement, or possessing a desire to improve their working environment. We analyzed factors affecting blood lead levels (PbBs). These factors were gender, age, employment duration, factory size, work environment control (WEC) class, and job categories. The PbB of men was found to be higher than that of women, and may be due to the differences in job distribution. PbB increased along with increasing age and employment duration. PbB declined as the factory size increased. The odds ratio (OR) of PbB higher than 20 microg/dl according to factory size was significantly high even after adjusting for WEC class. This demonstrates that not only the working environment but also safety management was poorer among small-scale factories that large-scale factories. The rise of PbB along with the increase of WEC class confirmed that the results of work environment measurement are correlated with individual exposure levels. The risk of having a 20 microg/dl or higher PbB was different for various lead handling jobs. Smelting or refining lead had the highest risk for lead exposure while painting or baking had the lowest risk. As our study population was not a randomly selected sample, we are unable to generalize our results for workers across Japan. However, we were able to indicate which jobs pose a high-risk and the effectiveness of using the work environment control class as an index of worksite environment levels.

Adult↗

PubMed2005

Development of rice husks-plastics composites for building materials.

In this paper, a new effective recycling method for rice husks and waste expanded polystyrene is developed by using a combination of both wastes. A styrene solution of waste expanded polystyrene is used as a binder for rice husks-plastics composites. The composites are prepared with various mix proportions by a hot press molding method, and tested for apparent density, water absorption, expansion in thickness, and dry and wet flexural strengths. From the test results, the apparent density of the composites is increased with increasing binder content and filler-binder ratio. Their flexural strength and wet flexural strengths reach maximums at a binder content of 30.0% and a filler-binder ratio of 1.0. Their water absorption and expansion in thickness are decreased with increasing binder content and filler-binder ratio. Since the composites have a high flexural strength and water resistance, their uses as building materials are expected.

Benzoyl Peroxide↗

PubMed2004

[Survey on visual and musculoskeletal symptoms in VDT workers].

With the spread of visual display terminals (VDT) in offices, the numbers of workers using VDT and the working hours at such equipment have increased rapidly in recent years. Also, preventive measures for fatigue have been proposed and the office-working environment has been improved. To examine the effects of the rapid changes in working conditions and environment on the health of VDT workers, we conducted a questionnaire survey in 2002. A self-reported questionnaire was distributed to 3,927 office workers; 2,374 (60.5%) responded. Subjects whose questionnaires had missing data were excluded from analysis. As a result, 1,406 (male: 1,069, female: 337) workers aged 20 to 59 were subjected to analysis. By a logistic regression model, we examined the association between VDT use and visual and musculoskeletal symptoms. Prevalence of eye strain and/or pain (72.1%) was the highest, followed by neck stiffness and/or pain (59.3%), low back stiffness and/or pain (30.0%) and hand or arm strain and/or pain (13.9%). Women consistently reported more discomfort than men. As a result of the logistic regression model, eye strain and/or pain was associated with dissatisfaction with airflow, but not with factors affecting visual symptoms as reported in previous studies, for example, reflection of light and blurred characters on the screen. It was thought that airflow appeared as a risk factor because the lighting environment had been improved in offices to prevent reflection of light on the screen. Neck stiffness and/or pain was associated with raising the shoulders during VDT work, the unsuitable shape of the computer mouse for a hand, and the inconvenient arrangement of the mouse in relation to the body. Hand or arm strain and/or pain were associated with the arrangement of the mouse and inappropriate height of the desk. Low back stiffness and/or pain were associated with dissatisfaction with the chair and using the keyboard without a wrist rest. Although measures to prevent fatigue had been implemented for VDT workers, risk factors for musculoskeletal symptoms would be the same as in previous studies.

Adult↗

PubMed2004

Shape and thickness of cushion in a standing aid to support a forward bending posture: effects on posture, muscle activities and subjective discomfort.

In order to prevent low back pain (LBP) during dishwashing, we developed three types of aid with a thick cushion for supporting the shins and evaluated the effects of the standing aid on the subjective discomfort and muscle activities. Nine female volunteers were asked to wash plates in each of four working postures: (a) without the standing aid, (b) with the round type of aid, (c) with the small rectangular type of aid, and (d) with the large rectangular type of aid. With the three types of aid, the subjects were instructed to support the shins with the standing aid and to support the abdomen with the edge of a kitchen counter. In the three postures with the standing aid, 21.5 +/- 10.0% of the weight was supported with the standing aid and the kitchen counter. The subjective discomfort was milder and the muscle activity level in the low back was lower in the three postures with the standing aid than in the posture without the aid. It was thought that the round type of aid would be more effective in decreasing the discomfort in many of body regions and the muscle load on the low back than either of the rectangular types of aid. Therefore, it was suggested that the standing aid had the desired effect in decreasing discomfort and muscle load on the low back during dishwashing.

Adult↗

PubMed2004

Development of action checkpoints for comfortable computer work.

We developed a manual including a checklist format for undertaking measures to prevent fatigue in visual display terminals (VDT) workers. With this manual, problems related to VDT work can be recognized by using checklists which allow for self-evaluation by the workers. The manual helps the workers to consider measures for improvement by themselves and will contribute to better occupational health education.

Computer Terminals↗

PubMed2003

Associations between oxidative stress levels and total duration of engagement in jobs with exposure to fly ash among workers at municipal solid waste incinerators.

The fly ash from municipal solid waste incinerators (MSWIs) is known to contain heavy metals, polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), polyaromatic hydrocarbons (PAHs), and other organic materials. Heavy metals, PCDDs, PCDFs and PAHs reportedly cause oxidative stress in vitro and in vivo. In this study, we have measured the blood and urinary levels of several oxidative stress markers in MSWI workers and discuss herein whether the duration of engagement in jobs with exposure to MSWI fly ash is associated with these levels. The subjects were 81 male workers (mean age 42.7 years) from four MSWIs in the same city. Job history was determined from each subject and jobs were categorized according to the possibility of exposure to fly ash. The subjects were classified into four groups: long duration of engagement in jobs with exposure to fly ash, short duration of engagement in jobs with exposure to fly ash, engagement in jobs with limited exposure to fly ash and control. Blood and urine specimens were obtained from the subjects in the morning before breakfast. The levels of 8-hydroxy-2'-deoxyguanosine (8-OH-dG) in the urine and leukocytes were measured as markers of oxidative DNA damage. Blood malondialdehyde and lipid peroxide levels and the level of total urinary biopyrrins were also measured as markers of systemic oxidative stress. The mean levels of all markers were compared among the four groups. There was a significant trend showing that the level of urinary 8-OH-dG rose with increased duration of engagement in jobs with exposure to MSWI fly ash (P<0.05). Considering this result, we speculate that certain chemicals in fly ash might have induced oxidative stress in the study subjects.

8-Hydroxy-2'-Deoxyguanosine↗

PubMed2002

[Stevens-Johnson syndrome accompanied by acute hepatitis in workers exposed to trichloroethylene or tetrachloroethylene].

Since the late 1980s, there has been an increasing tendency in the number of case reports on Stevens-Johnson syndrome accompanied by acute hepatitis in workers exposed to trichloroethylene from Asian countries. Recently, mass outbreaks of it have been disclosed in the Philippines and China. Besides trichloroethylene, although the number is small, a similar health disorder has also occurred in workers using tetrachloroethylene. Since the above-mentioned facts are not yet well recognized in the occupational health community, this review is aimed at making clear (1) the clinical features of the health disorder, (2) details of patients' jobs, working environments, and exposure to hazardous chemicals, and (3) the relationship between exposure to trichloroethylene or tetrachloroethylene and the health disorder. Based on a critical review of articles, the following were pointed out. First, it is important to carefully observe the health status of workers exposed to trichloroethylene or tetrachloroethylene and to take countermeasures to reduce exposure. Secondly, circumstantial evidence suggests a cause-effect relationship between the two chemicals and the health disorder; but at the present time it is impossible to rule out the participation of unelucidated factors promoting the occurrence of the health disorder or the existence of a hidden genuine causative substance. Therefore further investigation to trace such a case is needed. Thirdly, the mechanism of the health disorder and the reason why there seems to be a large inter-individual difference in sensitivity to the causative agent should be clarified.

Acute Disease↗