Diesel engines are widely used in industries, for example transportation, mining, and construction, because they efficiently produce high power. In diesel exhaust particles (DEP), the number of ultrafine particles, less than around 100 nm, is dominant in contrast to mass size distribution. Carcinogenic PAHs may be adsorbed on DEP at high concentrations. As occupational exposure usually occurs near emission sources, workers are likely to be exposed to high concentration DEP. The exhaust emissions of diesel engines have become lower by modification of the engines and fuels, and introduction of filters and catalysts, thus it has become more difficult to monitor mass and chemical components in DEP. New technology and instruments are being introduced to characterize DEP especially chemically. Recently, quick analytical methods without extraction, and continuous or semi-continuous methods have been introduced. This article will review 1) Elemental Carbon (EC) monitors, 2) analytical methods of individual PAH without solvent extraction, and 3) continuous PAH monitor, because EC and PAH are typical constituents for DEP.
To simulate the effects of prolonged standing in the workplace on the leg muscles, we subjected mice to centrifugation for 6 wk. The absolute wet weight of leg muscles and internal organs of mice were measured after exposure to 3G by centrifugation for 6 wk and at 2 wk after removal of centrifugation. The weight of the soleus muscle (antigravity muscle) significantly increased after 6-wk exposure to centrifugation, but it decreased to its control weight 2 wk after removal of centrifugation. In contrast, the wet weights of the anterior tibial muscle, liver, and kidneys of mice centrifuged for 6 wk were significantly lower than those of the control mice; they had returned to control levels 2 wk after removal of centrifugation. It was therefore suggested that prolonged standing enlarged the leg muscles but its effect did not last for a long period of time after stopping prolonged standing. Western blot analysis of proteins extracted from the soleus muscle showed that vinculin and α-actinin in the centrifuged mice increased slightly, but there were no differences in the heat shock protein 70 (HSP70) and desmin levels between the centrifuged mice and control mice. No difference in HSP 70 suggested that muscle damage did not exist after 6 wk centrifugation.
The aim of the study is to investigate whether traffic policemen exposed to urban pollutants and psycho-social stressors may be at risk of modifications in serum levels of immunoglobulins G antibodies (IgG Ab) against Herpes Simplex Virus (type1) (HSV-1) compared with controls. Traffic policemen were matched by sex, age, working life and drinking habits (less than two glasses of wine or beer per day) with controls, after excluding the subjects with the principal confounding factors (smoking habit, use of paints, solvents, pesticides and drinking habits). Were included in the study 125 traffic policemen (54 men and 71 women) with outdoor activity and 125 controls (54 men and 71 women) with indoor activity. Mean levels of IgG Ab against HSV-1 were significantly higher in traffic policemen of both sexes compared with controls. The frequency of workers with IgG Ab against HSV-1 levels higher than our normal laboratory values, was significant in traffic policemen compared with controls of both sexes. The distributions of IgG Ab against HSV-1 levels in traffic policemen compared with controls of both sexes were significant. The authors hypothesise an effect of the working activity in traffic policemen on serum levels of IgG Ab against HSV-1 compared to controls.
The present study was initiated to assess current level of general population exposure to lead (Pb) in terms of Pb in urine (Pb-U). For this purpose, spot urine samples were collected from 2, 332 never-smoking adult women in 10 areas all-over Japan, and were subjected to analysis for Pb-U by graphite furnace atomic absorption (GFAA). Data on cadmium in urine (Cd-U) as measured by GFAA were cited from a previous publication1). The grand geometric means (GM) for Pb-U as observed, as corrected for creatinine (cr) and as corrected for a specific gravity of 1.016 were 1.06μg/l, 1.28 μg/g cr and 1.14 μg/l, respectively, with small intra- and inter-variations with geometric standard deviations of about 2 or less. Arithmetic means of the 10 GMs (one each for the 10 areas) were 1.05 μg/l, 1.19 μg/g cr and 1.18 μg/l, respectively. The levels observed appeared to be lower than levels reported for other populations in the world. Chronological comparison within Japan suggested a gradual decrease in Pb-U in past over 20 yr. No close correlation was detected between Pb-U and Cd-U.
In Turkey, the construction sector is responsible for the largest number of work-related fatalities among all industries. This study's objective is to determine the characteristics of the fatalities in the construction sector in Kocaeli Province. The study was carried out retrospectively by investigating the records of occupational deaths between 1990 and 2001 in the Kocaeli District of Turkey. Fatal occupational injuries in the construction sector were investigated in detail by evaluating the records. The analysis was based on data from 153 deaths. The incidence of occupational injuries was found overall to be 4.5% in Kocaeli, while the annual mortality rate was 60.4 in Kocaeli and 79.0 in Turkey per 100, 000 workers over the entire time period. On the other hand, the fatality rate of occupational injuries was found to be 12.0 per 1, 000 in Turkey and 6.4 per 1, 000 in Kocaeli. The evaluation of the type of injuries in construction sector has revealed that in 69 of cases (45.1%) fell down from high altitude, in 22 cases (14.4%) vehicle accident, and in 22 (14.4%) electrocution were the cause of death. The leading causes of death have been found to be blunt-force trauma (37.9%) and head trauma (25.5%). Fourty one percent of those who had occupational accidents have had less than one year work experience. Only in 7.8% of deaths, the cause was determined through an autopsy.
Objectives: In order to clarify the effect of lead on higher cerebral functions, lead-exposed workers (Pb group) and controls were examined for event-related potentials. Subjects and Methods: Fourteen lead-exposed workers with a mean age of 57.1 yr (SD=4.27, range 48-64; lead concentration of whole blood ranged from 33 to 106 μg/dl with a mean of 58.6 and SD 28.6 μg/dl) and 19 agematched control workers with a mean age of 57.3 yr (SD=4.80, range 48-65) were examined. Visual P300 was recorded by button pushing to the target image (minute checkerboard pattern, 20%), and the NO-GO potential by no button pushing to the target image (same as above, 50%). Results: Latencies of P300 in the Pb group (475 ± 46.0 ms) were significantly delayed compared with those in controls (407 ± 42.4 ms, p<0.01 by Student's t test). Amplitudes of the NO-GO potential in the Pb group (4.59 ± 2.04 μV) significantly increased compared with those in the controls (3.18 ± 1.41 μV, p<0.05). Conclusion: The finding suggests that lead exposure affects high cerebral functions of cognition and attention, but is unclear in suppression of movement.
Malignant pleural mesothelioma is induced by asbestos exposure. Many reports have described this situation in America and European countries, but a few have been published in Japan. In this study malignant pleural mesothelioma cases in hospitals located in an area facing the Seto Inland Sea were evaluated. A total of 106 patients were examined with 100 patients having had occupational exposure to asbestos and 6 patients without such histories of asbestos exposure. Ninety seven were male and 9 were female. Ages ranged from 41 to 87 yr with mean of 64.8 ± 5.3 yr. Thirty seven cases showed epithelial type of tumor, 25 biphasic type and 15 showed sarcomatous. The remaining 23 cases had insufficient evidence for typing the tumor. The mean survival rate for all cases was 9.2 ± 11.6 months. Fifty-one patients had occupational histories of shipyard work, 16 patients worked in asbestos cement piping, and the remainder were employed in miscellaneous jobs related asbestos exposure. The duration of asbestos exposure ranged up to 20 yr or longer with the mean of 17.2 ± 8.9 yr and the average latent period for the occurrence of malignant pleural mesothelioma was more than 31 yr with the mean of 37.0 ± 13.3 yr. Quantification of asbestos bodies in the lungs indicated a high concentration in most patients and the major types of asbestos fibers were crocidolite and amosite. Six cases appeared after exposure to chrysotile. These results indicated that ninety four percent of malignant pleural mesothelioma appeared due to the exposure to asbestos including crocidolite and amosite. The remainder may be blamed on exposure to chrysotile.
We provided occupational health education as training to all workers (N=31) and managers, and collaborated with them against reducing the risk of lead poisoning of workers at an assembly section in a battery manufacturing plant in Bangkok, Thailand in 2002. After occupational health education, many workers (80.6-100.0%) noticed and understood the toxicity of lead and the importance of protection against it. Many workers regularly wore long sleeved shirt and trousers, and used the appropriate mask all day long. They changed the attitude toward their work and improved personal hygiene, for example no smoking in the workplace, washing their hands by a detergent before drinking water or having lunch, and taking a bath after the work. They especially took off working clothes at an office outside the workplace and washed them everyday. The average blood lead level of the workers significantly (P=0.002) reduced from 32.7 μg/dl to 22.4 μg/dl, although airborne lead level in the workplace remained unchanged with before conditions. From these results occupational health education and collaboration between workers and managers were effective tools to reduce the risk of lead poisoning of workers in a battery manufacturing plant.
Ethylene glycol monoethyl ether (EGEE) is a solvent commonly used in industry. To find the health effect of the solvent exposure in women, we did an investigation on 32 female workers exposed to EGEE in factories manufacturing photopolymer sensitization plate, and 20 subjects working in the same companies without potential exposure to the solvent. The mean age was 35.0 and 33.9 yr in the two groups, respectively. The mean concentration of the urinary metabolite (ethoxyacetic acid) was 120.87 mg/g creatinine (geometric mean) in the exposed group, and 2.71 mg/g creatinine in the control group. Average RBC count and hemoglobin levels were normal in both groups. However, there were 2 subjects in the exposed group with an RBC count and hemoglobin concentration slightly lower than the standard. Out of 20 controls, 5 subjects reported irregular menstruation, and in comparison, 4 out of 32 exposed females had the same complaint. The most common health complaints were dizziness and swelling of the legs, with the same frequencies seen in both groups. Overall, our study suggests that although female workers were exposed to high concentrations of EGEE, subsequent health problems possibly due to such exposure were not significant.