Lead was administered to pregnant rats in drinking water (5 ppm) from day 1 to day 18 or 21 of gestation, at which time the dams and fetuses were sacrificed. The red blood cell count and hemoglobin concentration were significantly lower in the lead-treated fetuses than in untreated controls on day 21 of gestation, but not in the lead-treated dams. The delta-aminolevulinic acid dehydratase (ALAD) activity of erythrocytes was significantly reduced in the lead-treated dams and their fetuses on days 18 and 21 of gestation. AL AD activity in the liver was significantly higher in the leadtreated fetuses than in the controls. There was no significant difference in placental AL AD activity between the lead-treated and control animals. Lead in tissues increased significantly in the liver of the lead-treated fetuses. There were significant positive correlations between the maternal and fetal blood lead level, liver lead level and erythrocyte ALAD activity. There was a significant negative correlation between the maternal and fetal liver ALAD activity.
Cadmium when administered to animals is known to accumulate in the liver and kidney, causing identifiable toxic effects. These effects on enzyme systems have been described in the present investigation selecting few of them viz. alkaline phosphatase, acid phosphatase, glucse-6-phosphatase and cholinesterase in the liver of rat, Rattus rattus albino. Topographical study on dysenzymia thus made have been found helpful in manifesting further the mechanism of Cd toxicity. Variations in the level of enzyme protein, state of cellular organelle together with processes of phosphorylation, adenylation and oxidative phosphorylation have been discussed explaining the cause and significance of these changes in enzyme activity.
Rats were exposed to toluene and xylene at 200-800 ppm for 30 days. After exposure, changes in the dopamine, norepinephrine, serotonin, acetylcholine (ACh), cyclic AMP, cyclic GMP, GABA, glutamic acid, glutamine, aspartic acid, taurine, glycine and alanine content of different areas of the brain were investigated. ACh ih the striatum and whole brain were reduced dosedependently by toluene and xylene. The reduction at 800 ppm of the solvents was in the range of 10 to 20% of the ACh content of the control rats. Toluene and xylene caused different changes in monoamine content other than ACh, but the changes were not dose-dependent. Among the seven free amino acids that are the main amino acid components of the brain, the glutamine content was increased by toluene and xylene at 800 ppm. Decrease in ACh and increase in glutamine in the brain appear to be phenomena common to many kinds of organic solvents including toluene and xylene after acute and subacute exposure.
This experiment is intended to clarify the changes in the sleep cycle and EEG of rats exposed to toluene vapor. Chronically implanted electrodes were used to record the cortical and hippocampal EEGs, cervical EMG and pulse rate. The rats were exposed to 4000 ppm toluene vapor from 4 to 8 p.m. daily for four weeks. Polygraphs were recorded from noon to 4 p.m. before exposure, after four weeks' exposure and a week after the termination of exposure. With regard to the sleep cycle, it was observed that the percent time of the wakefulness phase increased, while those of the slow-wave and paradoxical phases decreased, and the rhythm of the sleep cycle became irregular after four weeks' exposure. As for the EEG patterns, it was noted that the spindle wave of the spindle phase changed in the appearance rate, shape and frequency, and the fast components of the cortical and hippocampal EEGs increased in the slow-wave phase after four weeks' exposure. The changes in the sleep cycle and EEGs continued for a week after the termination of exposure, although they became less marked. It was thought that analysis of the changes in the sleep cycle and EEG would serve as an index of the effects of toluene on the central nervous system.
The acute effects of toluene on sleep-waking rhythms were investigated in rats. In order to determine the characteristics of sleep-waking rhythms in rats quantitatively, polygraphic recordings of cortical EEG activity and neck EMG were made under a 12 : 12 light-dark schedule. Toluene was injected intraperitoneally at three dosages, i.e., 200, 400 and 600 mg/kg of body weight. The toluene con-centration in the blood was determined in rats implanted with a jugular catheter to collect the blood. The circadian sleep-waking rhythms were still entrained to the environmental light-dark cycle following the administration of toluene. On the day of administration, wakefulness (W) increased immediately after toluene administration at the lower two doses, and an abnormal EEG pattern was observed transiently at the highest dose. The initial increase in W at 200 and 400 mg/kg and the appearance of the abnormal EEG pattern at 600 mg/kg were observed for 32, 79 and 83 min. after the administration of toluene, respectively. The toluene concentration in the blood of rats given 600 mg/kg was about 70 μg/ml when the abnormal EEG disappeared. Slow wave sleep (SWS) and paradoxical sleep (PS) increased during the period when blood toluene levels decreased. On the second day, when almost all of the toluene was eliminated from the blood, the lowest dose produced an increase in PS during the dark period, and the higher two doses produced a decrease in PS during the light period. At the highest dose, the amount of SWS during the light period was still higher than control. Toluene-induced changes in the sleep-waking rhythms returned to the control by the third day.
Organic solvent products used in the various factories were collected nationwide in Japan, and analyzed by gas chromatogarphy. Of the 1179 samples collected, 522 samples were homogeneous (including 321 thinners, 145 degreasers and 56 reagents and others), and were analyzed by means of direct injection into a FID-gas chromatograph with two FSWCOT (OV 101 and PEG 6000) capillary columns. In thinners (n=248), the average number of solvent components per sample was 4.14 when the thinners containing gasoline were excluded. Toluene was the most popular component in thinners (present in 56%) followed by ethyl acetate, methanol, xylenes, ethylbenzene, isobutyl alcohol, ethyleneglycol mono-ethylether acetate, butyl acetate and methyl isobutyl ketone. Gasoline was also detected in 23%. In degreasers (n=123), the average number of solvent components per sample was 1.64 when the degreasers containing gasoline were not taken into account. Trichloroethylene was present in 21% of degreasers followed by tetrachloroethylene, 1, 1, 1-trichloroethane, toluene, acetone, xylenes and ethyl-benzene. Gasoline was found in 14%. A small amount of 1, 4-dioxane was detected as an additive in every 1, 1, 1, -trichloroethane products. With regard to reagents and others (n=53), the avarage number of components per sample was 1.40 if samples containig gasoline were excluded, and most (73%) of reagents and others (n=41) consisted of a single component. The potent toxic solvents such as benzene, chloroform, carbon tetrachloride, 1, 2-dichloroethane, 1, 1, 2-trichloro-ethane, 1, 1, 2, 2-tetrachloroethane and carbon disulfide were only rarely found in the present homogeneous products.
Commercial heterogeneous solvent products (e.g., paints, inks and ad-hesives) were collected nationwide in Japan in 1980. The vapor phase of the product containers were analyzed for volatile organic solvent constituents by means of FID-gas chromatography on two FS-WCOT (OV-101 and PEG-600) capillary columns. Of 657 products collected (358 paints, 62 inks, 165 abhesives and 72 others), 136 samples were not analyzable because 75 gave numerous peaks (presumably containing gasoline) and others had no volatile component. Among the remaining 521 samples (298 paints, 52 inks, 120 achesives and 51 others), 70 gave only one peak while others gave multiple peaks, indicating the mixture of solvents rather than single solvent was commonly used. Of the organic solvent components identified, toluene was the most popular solvent throughout paints (appearing in 80%), inks (62%), adhesives (51%) and others (65%), being detected in 70% of the total products analyzed. This popularity of toluene was followed by xylenes [predominantly m-(66%) and p-isomer (61%, )] in the case of paints, isopropyl alcohol (35%) in inks, and n-hexane (27%) and methyl ethyl ketone (23%) in adhesives, while benzene was not detected in any samples analyzed nor even in the gasoline-containing products. The concentrations of each solvent component in the vapor phases varied depending on the products, following a log-normal distribution. When the relative exposure risk of each of eight leading solvents of various chemical structures was calculated as the geometric mean concentration multiplied by the frequency of detection, n-hexane in adhesives was highest in the risk ranking while toluene and xylenes in paints scored much less because of low volatility.
The Medical Data Index (MDI) health questionnaire was given to 924 women clerks engaged in Visual Display Terminal (VDT) work in the head or branch offices of a city bank. In order to estimate the interrelation and relevance of the health complaints of the 150 MDI items, characteristics of the 34 main complaints of these women were analyzed by means of tetrachoric correlation coefficients and factor analysis. The tendency of many complaints considered to be related to mental strain and eye impairment was the dominant factor in the sense that the eigen value of this factor was extremely high.
A surveillance system for gathering and analyzing working environment measurement records as well as the medical examination records kept in most workplaces every year has been implemented. With few exceptions, these records have never been adequetely used as statistical data being processed by a central administrative organ. Research samples are limited to the workplaces under any-thing but good conditions, of industrial health management for the present. Besides this, we have only two types of records, those being utilized for screening of pneumoconiosis and a health effect of organic solvents, as the initial medical ex-amination data. It might be of considerable interest that questionnaire items contain the data on medical certificates that are presented by workers when they take sick leave. This system would be able to provide fruitful material as to such an important theme in the industrial health services field as the relationship between the working environment and health in the future.