Regarding colophony, the use in industries, adverse effects, diagnosis, pathophysiology and control are reviewed. Colophony is an unhomogeneous mixture of resin acids as like abietic acid and neutral substances. Colophony is used everywhere, in industry, daily life and medical supplies. Soldering workers are exposed to the colophony fumes heated up to the temperature of soldering irons. The effects of exposure to colophony are classified into bronchial asthma and contact dermatitis. Colophony fumes cause brochial asthma by its nonspecific irritation. Inhalation challenge test and repeated spirometry during working day may help the diagnosis of colophony induced asthma. Improvement of working environment for soldering and development of new flux instead of colophony will be necessary. A study on contact dermatitis revealed that colophony and its related compounds are one of major causes for contact dermatitis. Cases of dermatitis by depilatory agents used to remove hair from slaughtered swine, anti-slipping cream for ballet shoes or resin for cello strings have been reported. Patch test may contribute to the diagnosis of dermatitis caused by colophony.
The aim of the study is to know the effects of occupational factors and smoking habits on tobacco withdrawal symptoms among male Japanese employees. A total of 2, 862 male employees in a company in Japan completed questionnaires concerning tobacco withdrawal symptoms, occupational factors (occupation, shift work, work stress) and smoking habits. Data from 1, 443 male ever-quitters were analyzed. Among male ever-quitters, 67% had ever experienced tobacco withdrawal symptoms. Significantly higher age-adjusted rates of tobacco withdrawal symptoms were found in those who experienced frequent exhaustion after work, current smokers, those who smoked 20 or more cigarettes per day, smoked for 20 years or longer and tried to quit smoking twice or more (p<0.05). Multiple logistic regression analysis indicated that younger age, technical/clerical occupation, exhaustion after work, number of cigarettes smoked per day, duration of smoking, currently smoking and number of trials to quit smoking, were significantly associated with tobacco withdrawal symptoms (p<0.05). It is suggested that younger age, technical/clerical occupation, exhaustion after work, number of cigarettes smoked and duration of smoking are risk factors of tobacco withdrawal symptoms in male Japanese employees.
The aim was to study the actual situation of subjective fatigue among the Vietnamese workers in factories with newly imported technology. A cross-sectional study concerning working conditions and the fatigue complaints of 389 workers who are employed in 10 Vietnamese factories with newly imported technology, was conducted from August to September 1994. About 60% of the workers were satisfied with their current working conditions. Regarding occupational risks at the workplace, heat, dust and noise were identified as the three most dangerous risks. About 46% of the workers complained about the incompatibility of the machines and equipment they were using, which are too large for Vietnamese workers. One third of all workers felt that the work pace is too rapid. Seventeen percent of the workers considered their working conditions monotonous. Finally, among 150 female workers under 40 years old, 45 workers (30.0%) complained of irregularity of menstruation. Generally these problems were more common among workers in textile factories. The prevalence rate of subjective fatigue complaints was significantly increased after work in all 30 items. The fatigue level were substantially high among workers in textile factories. Female workers in this sector had a high prevalence rate of irregularity of menstruation. There were many problems observed in the Vietnamese factories with newly imported technology. Special consideration is required to improve the working conditions of female workers in the textile industry. Both the Vietnamese government and donor countries have to give special attention to the transfer of worker-friendly technology to Vietnam, in order to achieve sound economic development.
In order to evaluate the relationship between job stress and mental health, a cross-sectional study was conducted using a questionnaire relating to demographics, subjective job stress and mental health state. The questionnaire consisted of a 30-item Japanese version of the General Health Questionnaire (GHQ) developed by Goldberg in addition to questions about subjective job stress, to measure mental health and job stress conditions, respectively. All subjects were employees of an electronic company in Japan. Among 782 workers, 763 workers responded to the questionnaire satisfactorily (response rate was 97.6%). People whose GHQ score was more than 7 were classified as having psychiatric problems, while the remaining respondents were considered as having no mental health problems. We employed a multiple logistic regression analysis to estimate the relationship between subjective job stress and mental health, adjusting for gender, age, marital state, familial stress, and physical health state. Subjective job stress was significantly associated with the state of mental health. In particular, the items of “too much trouble at work, ” “too much responsibility, ” “are not allowed to make mistakes, ” “poor relationship with superiors, ” and “cannot keep up with technology” were significantly related to mental health.
This study investigated the effectiveness of several possible exercises for performance during standing work in order to prevent lower leg swelling and relieve subjective complaints. Volume changes in the lower leg were measured using bioelectrical impedance plethysmography in 13 healthy male subjects aged 23-36 years. Subjective complaints of leg pain, leg dullness and whole body fatigue were also recorded. Measurements were performed at two-minute intervals during a one-hour period of standing with insertions of one-minute of exercise every 10min. The exercises were knee-bending, foot-stepping, walking, and heel-raising. The change rates of impedance over one hour were 2.2%, 4.0%, 4.6%, and 6.3%, respectively, indicating that leg volume was increased under all exercise conditions. Among exercises, the swell-preventing effect of knee-bending was strongest, and that of heel-raising was weakest. Heel-raising also yielded the highest number of subjective complaints. Knee-bending, which uses the thigh and calf muscles simultaneously, was considered the most effective for suppressing lower-leg swelling and minimizing subjective complaints.
The effects of bright artificial light on the subjective mental state of 10 female nurses working shifts at a university hospital were assessed. We investigated two series of five consecutive workshifts rotations comprising one normal, two night and two evening shifts, using two self-administered rating scales. The subjects were exposed to artificial light, brighter than 3, 000lux, for a total of 30min during each workshift of the second series, whereas they worked under normal lighting conditions (approximately 250lux) during the first series. A three-way layout ANOVA, with repeated measures, revealed that bright light tended to improve eagerness and reduce tension, and improved vigor, eagerness, appetite and impairment (the latter only on the second night) significantly or nearly significantly during night, but not evening, shifts. These results suggest that bright artificial light affects the mental state of nurses during night, but not evening, shift work.
To determine the interaction effect of illumination with noise performance data were recorded from 20 male college student volunteers on a battery of neuropsychological tests comprising ‘memory and search, ’ ‘name and number checking, ’ ‘Flanagan's eye-hand coordination’ and ‘digit symbol.’ Each subject worked under two of the four combinations of illumination (low, 300lux; high, 500lux) with quiet (60dBA) and noise (100dBA) conditions. A 2×2 analysis of variance was performed on the test scores. The accuracy of performance was found enhanced by high illumination in all the tests, but the speed of performance was impaired by noise. The interaction effect was significant, indicating the speed and efficiency of performance increasing while the accuracy of performance affected differently with high illumination under noise condition. However, the error of performance increased by noise under high illumination. Further investigation on a range of neuropsychological tests is suggested before the conclusions are drawn more firmly.
To investigate the effects of prolonged mental work, urinary excretion of catecholamines and cortisol was measured in 18 human subjects from 9:30 to 17:00. On the ‘task day, ’ the subjects performed mental tasks during the morning (10:20-11:45) and afternoon sessions(13:00-17:00), otherwise taking chair rest. On the ‘control day, ’ the subjects took chair rest in the afternoon after performing mental tasks in the morning. In the morning session, urinary excretion of adrenaline during mental work increased greatly compared to that before the mental work. Mental work in the afternoon session also caused a marked increase in adrenaline excretion compared to the rest level in the afternoon on the control day. Cortisol levels in the first hour of the afternoon mental work were significantly higher than those during the corresponding time on the control day. Urinary excretion of noradrenaline during mental work in the morning session only increased slightly compared to that before the mental work. In the afternoon session, however, noradrenaline excretion during mental work on the task day was markedly elevated compared to that during the rest condition at the corresponding time on the control day. These findings suggest that prolonged exposure to mental work, but not short-term mental work, produces a marked increase in noradrenaline excretion in human subjects.
To clarify the instillation toxicity of low level of indium phosphide (InP), 0, 1.2, 6.0 and 62.0μg/kg body weight of InP particles were instilled intratracheally in male Fischer 344 rats, and the effects of InP were examined on the following day (day 1) and on the 8th day (day 8) after instillation. Indium was measured but not detected in the serum, liver, kidney, spleen, thymus and brain. Dose-related mild elevation of superoxide dismutase (SOD) activity and lactate dehydrogenase (LDH) activity in bronchoalveolar lavage fluid (BALF) were found on day 1 without increases of inflammatory cells and total protein (TP) in BALF, which suggested the response of neutrophils and alveolar macrophages to instilled InP, and/or the manifestation of a very early stage of inflammation. Only in the 62.0μg/kg-instilled group on day 8, were neutrophils, lymphocytes, TP, LDH, total phospholipid and total cholesterol in BALF increased, and desquamation of alveolar epithelial cells and amorphous exudate in alveolar lumen observed by histopathological examination. These results suggested that InP caused pulmonary inflammation and epithelial cell damage up to 8 days following instillation dose of 62.0μg/kg, but that its effect was considered irrelevant at instillation doses of 6.0 μg/kg or below in rat.
Acute and subacute lung toxicity of nickel fumes was examined by single and repeated intratracheal instillation of nickel fumes and Ni2O3 and NiO powders in the rat. LD50 of nickel fumes was estimated as 38.2mg/kg body weight (b.w.) according to the method of Litchfield and Wilcoxon. Body weight gain was retarded as in the order of a single dose of 13.0mg Ni2O3/kg>14.3 mg nickel fumes/kg>1.4mg Ni2O3/kg>13.0mg NiO/kg b.w. compared to controls. The histopathological changes in the lungs of the 14.3mg nickel fumes/kg-dosed rats were milder than those induced by administration of 13.0mg Ni2O3/kg but severer than those induced by administration of 1.4mg Ni2O3/kg b.w. A single administration of NiO powder did not produce any histopathological effects on the lungs. The repeated administration of nickel fumes produced persistent edema and proteinosis in the alveoli. The nickel fumes, which were chemically composed of 97% of NiO and 3% of Ni2O3, were very fine particles about 5-10nm in diameter, partly aggregated into larger particles and spherical particles about 0.6μm in diameter. Solubility in distilled water and saline was in the order of nickel fumes>Ni2O3 powder_??_NiO powder. It was suggested that a toxic Ni2O3 component and very fine particles of nickel fumes are involved in the acute lung toxicity of nickel fumes. The epithelial injury induced by reactive oxygen and hydroxy radicals, which would be produced during the process of conversion of Ni(III) to Ni(II) and phagocytosis of nickel fumes by macrophages and polymorphonuclear cells, are presumed to be involved in the pathogenesis of nickel fumes-induced lung lesion.
To evaluate the effect of age on toxicant-induced pulmonary and extrapulmonary changes, we examined the effect of inhalation exposure to ozone (O3) on the ventilatory and heart rate (HR) responses in 4-6 and 20-22-month-old male rats. The rats, chronically implanted with an electrocardiographic (ECG) electrodes, were placed in a head-out plethysmograph for continuous ventilatory measurements of tidal volume and breathing frequency. Simultaneous measurements of HR were also obtained. A 6-hr exposure of each rat to filtered air was followed 2 days later by a 5-hr exposure to 0.1ppm O3, 5 days later by a 5-hr exposure to 0.3ppm O3 and 10 days later by a 5-hr exposure to 0.5ppm O3. Each of the O3 exposures was preceded by a 1-hr exposure to filtered air. Transient rapid shallow breathing with slightly increased HR appeared 1-2min after the start of O3 exposure. It was suggested on the basis of the electroencephalographic (EEG) activity of the olfactory bulb that this transient response was mediated through olfactory sensation. Persistent rapid shallow breathing with a progressive decrease in HR occurred with a latent period of 1-2hr. The last 90-min averaged values for relative minute ventilation tended to decrease with the increase in the level of exposure to O3 and these values for young rats were significantly lower than those for old rats. An exposure of young rats to 0.1ppm O3 for shorter than 5hr significantly decreased the tidal volumeand HR and increased breathing frequency, but no significant changes were observed in old rats. There were no differences between young and old rats in non-observable-adverse-effect-levels (NOAELs) for the O3-induced persistent ventilatory and HR responses, when the NOAELs were determined by exposure to 0.3 and 0.5ppm O3. The present results, as well as the reported decrease in body temperature and blood pressure, suggested that the age-related changes in patterns and magnitude of the persistent rapid shallow breathing with a progressive decrease in HR are mediated through some age-related defense mechanism acting against O3 inhalation. The validity of the occupational exposure limit for O3 in workplaces was discussed in the light of the present findings.
2-Bromopropane (2BP, isopropyl bromide), a substitute for freon, has recently been suspected to be the causative chemical for the outbreak of some reproductive dysfunctions such as amenorrhea and oligospermia in workers who has been exposed to this solvent in an electronic factory. Bacterial mutation assays, chromosome aberration analysis in vitro, and micronucleus tests in vivo, were carried out to clarify the mutagenicity of 2BP. 2BP induced mutagenicity in Salmonellatyphimurium TA100 with metabolic activation in a dose-dependant manner. 2BP induced mutagenicity in TA1535 as well, with or without metabolic activation. These observations indicated that 2BP induced the base-pair substitution type mutations in Salmonella strains. The chromosome aberration analysis showed negative results in Chinese hamster lung cells treated with different concentrations, ranging from 0.077 to 2.46mg/ml for 6h with metabolic activation and for 24h without metabolic activation. The micronucleus frequencies were recorded by examining polychromatic erythrocytes in the bone marrows of rats which were intraperitoneally injected with 2BP for 28 days. There was no significant increase in the micronucleus frequencies at any of the different doses of 2BP (125mg/ kg b.w./day, 250mg/kg b.w./day, and 500mg/kg b.w./day). However, in comparison to controls, there was a significant decrease in the percentage of polychromatic erythrocytes in the total number of erythrocytes. This suggests that there may be bone marrow depression in hematopoiesis at these dose levels of 2BP. Despite the dose levels which showed hematopoietic inhibition in the bone marrow, no micronucleus formation was induced.
The possible induction of a metallothionein (MT)-like Cadmium (Cd) binding protein (MT-like Cd-BP) was investigated in rat testis after oral Cd administration. Male Wistar rats were given Cd by oral administration (20mgCd/kg, for 10 weeks), while the experimental controls were given Cd by intraperitoneal (ip) injection (2mgCd/kg). Cd concentration increased in the testes after both administrations. However, much more Cd (about 4 times) accumulated in the testes of rats receiving oral Cd administration than in rats receiving Cd ip injection (experimental control). Meanwhile, MT-like Cd-BP decreased dramatically in the testes after Cd ip injection compared to that in the testes of untreated control rats. However, this testicular MT-like Cd-BP after oral Cd administration increased significantly up to about 1.4 times of the amount found in the testes of untreated control rats. Inhibition of glutathione S-transferase (GST) activity and decreased glutathione (GSH) in the testes was not observed in rats after oral Cd administration. However, enzyme activity and GSH concentration were inhibited and decreased significantly in the testis by Cd toxicity after Cd ip injection. These results indicate that testicular MT-like Cd-BP, assumed to be MT and to be hardly inducible by Cd, is an inducible protein corresponding to increased Cd accumulation in the testis without damage by Cd toxicity after oral Cd administration.
Mancozeb-a fungicide of ethylenebisdithiocarbamate group was orally administered at doses of 500, 1, 000 and 1, 500mg/kg body weight/day for 30, 90, 180 and 360 days. Signs of toxicity mortality pattern and loss in body weight were observed in dose dependent manner. However, signs of intoxication and mortality pattern were more pronounced till the exposure of 90 days. A significant increase in testes and decrease in epididymis weight were associated with degeneration in seminiferous and epididymal tubules with loss of sperms. The decrease in gonadal acid phosphatase (ACP), succinic dehydrogenase (SDH) and increase in alkaline phosphatase (ALP), lactate dehydrogenase (LDH) activity were observed with increased serum cholesterol. Sialic acid and protein content of testis and epididymis were also decreased in dose dependent manner. The study has thus indicated marked biochemical and pathological changes in gonads of male rats after chronic exposure to mancozeb.
Nitrous oxide (N2O) is one of the most common inhalation anesthetics in current anesthesiological practice. Even though artificial ventilation and active scavenging in operating theaters are employed in most of the modern hospitals, potential N2O contamination persists in regular anesthesia, particularly pediatric operation. In order to understand personal exposure during pediatric anesthesia, ambient monitoring for N2O exposure around the breathing zone of theanesthesiologist was conducted by a portable infra-red Miran 1B2 spectrophotometer. The results demonstrated that general mask anesthesia generated greatest N2O contamination, with the mean time-weighted-average (TWA) concentrations of 85±48.4 (mean±S.D.) ppm in 12 cases. Initial mask induction followed by cuffed endotracheal incubation (6 cases) or intravenous induction followed by uncuffed endotracheal intubation (6 cases) also produced significant pollution to the workers, with the mean TWAs of 33.2±24.0ppm and 31.9±18.0ppm respectively. These procedures provided exposure levels above the 25ppm Recommended Exposure Limit (REL) of the National Institute of Occupational Safety and Health (NIOSH), U.S.A.1) Modification with intravenous induction followed with cuffed endotracheal intubation or mask general anesthesia provided with a ventilation hood diminished the contamination apparently, with the resulting mean TWAs of 11.0±4.7ppm and 17.9 ±9.8ppm in 7 and 5 cases respectively. The results indicated that excessive N2O exposure to anesthesiologists was not negligible during routine pediatric anesthesia. Significant reduction could be achieved via appropriate industrial modification.
Carbon monoxide (CO) level in three different tunnels in Boston area have been measured during rush hour periods, and expected CO exposure of construction workers who possibly work there was also estimated. CO levels in these tunnels have been measured at outside of a car running through the tunnels. The data collected in this study include vehicle speed, length of tunnels and traffic volume. In addition, structure of each tunnel was investigated. These data were used to estimate relationship between CO level and the distance of sampling points from entrance/exit of each tunnel. CO concentration in each tunnel was distributed in the range of 5ppm-42ppm, and linear relationship between CO concentration and distance from entrance/exit has been observed. This study had been held from April 1989 to May 1989 in Boston, MA, U.S.A.
A simple fiber length-reduction method was developed to obtain a large amount of fiber samples with different length distributions for use in various biological experiments. This press method is only to press a raw fiber sample charged in a stainless cylinder at an adequate pressure, and is effective for man-made mineral fibers (MMMF) such as glass wool, rock wool and refractory fibers (ceramic fibers, mullite fibers) and some brittle natural mineral fibers such as fibrous brucite and wollastomte. The mean fiber-length of man-made mineral fibers became shorter with the increase in the pressure applied without diameter change. We could obtain a length-reduced fiber sample with a suitable length distribution by this method. This press method is therefore a size-selective method able to produce a large amount of pulverized fiber sample depending on the press cylinder size for biological experiments. A very small amount of non-fibrous particles with aspect ratios (length vs. diameter) of under 3 was seen in the pulverized fiber samples. To eliminate such non-fibrous particles as well as too long fibers from the sample, separation by sedimentation in water was somewhat effective.
The characteristics of airflow (pressure loss and entry loss factor) were measured around a circular slot hood for its application to a local exhaust system. Centerline velocity, defined as the ratio of air velocity on the centerline of the slot hood to average slot face velocity, was found to be independent of the airflow rate. The relationship between the centerline velocity and the ratio of centerline distance to slot width was also found to be independent of the slot size. The empirical centerline velocity equation for the circular slot hood was thus constructed to design the local exhaust system. Recommended values for airflow rate into the circular slot hood and the average slot face velocity were found to be 20.14m3/min and 8.55m/sec, respectively. The optimum air velocity at a capture point was also found to be 5% of the average slot face velocity, i.e. 0.43m/sec, and the effective ventilation with the hood was achieved with these values. The local exhaust system with the circular slot hood was installed for a mixing process of fine particles and organic solvents in a magnetic coating works. The effectiveness of the circular slot hood was confirmed by measuring the concentrations of airborne particles and vapors before and during the operation of the local exhaust system.