Lack of knowledge of the exact contents of the materials and improper han-dling of the toxic chemicals lead to the occurrence of occupational illnesses in the developing countries. However, the incidence of occupational diseases was usually un-derestimated. This article presents the profile of occupational diseases in Taiwan from two sources, i.e. occupational disease benefit payments of labor insurance and the review of relevant literature. The primarily documented occupational diseases in Taiwan were pneumoconioses. The second most common occupational disease was carbon monoxide intoxication, followed by lead poisoning and noise-induced hearing loss. Less than five percent of occupational diseases were due to the other causes, including decompression syndrome, heat stroke, toxic hepatitis, neurological disorders and hematologic disorders. The number of occupational diseases recognized in Taiwan was considered to be seriously underestimated due to the shortage of occupational medical specialists. Priority in the development of occupational medicine in Taiwan is to educate industrial hygienists and physicians to recognize health hazards in the work environment and to diagnose occu-pational diseases. Recognition of occupational diseases could subsequently highlight the health hazards in the workplace and prevent workers from overexposure.
Urinary α1-microglobulin (α1-m) and β2-microglobulin (β2-m) can be used as early indicators of renal tubular dysfunction. However, low levels of lead exposure cause an increase in urinary α1-m, but not in urinary β2-m. In order to clarify the level of tubular dysfunction in early lead nephropathy, fractional clearances of α1-m (FC-α1-m) and β2-m (FC-β2-m), i.e., the ratios of these clearances to the creatinine clearance, were measured in 99 male lead workers. Blood urea nitrogen, serum creatinine, uric acid, and urinary creatinine and N-acetyl-β-D-glucosaminidase activity were also measured to di-agnose the presence of other renal dysfunction. The median of FC-α1-m was 0.13% in the control group. The FC-α1-m increased in lead workers with blood lead (B-Pb) levels above 20 μg/dl. The correlation of FC-α1-m with urinary α1-m was highly significant, but there was no correlation with serum α1-m. The median of FC-β2-m was 0.065% in the control group. There was a correlation of FC-β2-m with FC-α1-m, but there was no correlation with B-Pb, or with serum β2-m. These results suggest the following: There was a very low excretion rate of α1-m and β2-m in both the control group and the lead exposed groups. The excretion rate of α1-m was higher than that of β2-m. There seemed to be slight a dysfunction of tubular reabsorption in the lead workers, and the elevation of α1-m excretion reflected the dysfunction more sensitively than the elevation of β2-m excretion in lead poisoning.
Age-related effects of trichloroethylene (TRI) inhalation on heart rate (HR), its circadian rhythm, the incidence of spontaneous bradyarrhythmias (BA) and ventricu-lar premature contractions (VPC) were examined in conscious rats, as was the depen-dence of arrhythmias on sleep-wakefulness. Indwelling electrodes were used for simul-taneous electrocardiographic (ECG), electroencephalographic (EEG) and electromyographic (EMG) measurements in 2, 13, 20 and 26-month old rats. The rats were exposed for 8 hours to 300 ppm TRI followed by exposure to clean air for 7 days, after which they were exposed to 1, 000 ppm for 8 hours. The polygraphic recordings were made during 8-hr exposures and for 28 hours thereafter. Control values for all physiological param-eters were measured during 36-hr exposure to clean air. The exposure to TRI exacer-bated an age-dependent decrease in HR and its circadian amplitude. Although the spontaneous BA incidence decreased with advancing age, the ratio of the number of BA episodes during the post-exposure period after TRI exposure to those during the corre-sponding period of clean-air exposure increased more pronouncedly for 20 and 26-month old rats than for 2 and 13-month old rats. The number of spontaneous VPC episodes increased for 20 and 26-month old rats but was not affected by the exposure to TRI. Gas chromatographic analysis of TRI and free trichloroethanol (TRI-OH) in the brain and blood of the TRI-exposed rats revealed the prolonged half-life of TRI and the delayed clearance of free TRI-OH from the tissues with advancing age. The age-related exac-erbation of those ECG responses to TRI inhalation appears to be brought about in part by the age-related change in the pharmacokinetics of TRI and TRI-OH.
We investigated the effects of oral administration of 28 organic chemical agents, all of which possess neurotoxicity and most of which are used as industrial solvents, on monoamine neurotransmitters and metabolites in the rat brain. Each chemical was administered to rats singly at a dose of one-quarter the LD50 value. Two hours after administration, acetylcholine, 3, 4-dihydroxyphenylalanine (DOPA), dopamine, 3, 4-dihydroxyphenylacetic acid (DOPAC), homovanillic acid (HVA), norepinephrine, 3-methoxy-4-hydroxyphenylglycol (MHPG), serotonin, and 5-hydroxyindoleacetic acid (5HIAA) contents in the small-brain regions were measured. Twenty-one of the 28 chemicals increased acetylcholine in the hippocampus, a ratio (21/28) far higher than the 0.5 expected were these chemicals to have no tendency to increase or decrease acetyl-choline. This ratio was calculated for each brain substance. Large differences from 0.5 were also obtained for DOPAC (higher), and for 5HIAA and three neurotransmitters (dopamine, norepinephrine, and serotonin) in the hypothalamus (all lower). The ratios for MHPG and 5HIAA in the medulla oblongata were very high. In the hypothalamus, the concentrations of brain substances were easily altered by the test chemicals, and the turnover rates of hypothalamic norepinephrine and serotonin in the medulla oblongata
A speciation method for vanadium(IV) and vanadium(V) is presented that uses a combination of HPLC and ICP-AES. In this method, 1 mM HNO3 solution and 100 mM HNO3 solution were applied in sequence as eluent. A vanadium(IV) and vanadium(V) mixture was injected into a HPLC anion-exchange column; and vanadium(IV) cation was then eluted by 1 mM HNO3, while vanadium(V) oxoacid anion was trapped on the column. After this separation, vanadium(V) was eluted as a cation from the column by 100 mM HNO3. Vanadium was detected by ICP-AES. In this separation, about 15% of vanadium(V) interfered with vanadium(IV), and trace vanadium(IV) interfered with vanadium(V). This interference could be estimated by simple calculation based on stan-dard observations, and the speciation of vanadium(IV) and vanadium(V) was performed. The lower determination limit was 1 μg/mL, which is insufficient to speciate vanadium sampled by conventional sampling methods in a working environment. However, impu-rity of the other valent vanadium species in a vanadium(V) reagent can be determined by the present method, which should be valuable in precisely assessing the toxicities of vanadium species.
The purpose of this study was to determine physical fitness level of lignite miners in the Czech Republic. The authors have examined a representative group of 152 active lignite miners by bicycle spiroergometry. The duration of employment in coal mines ranged between 5 and 32 years. The average age was 43.1 ± 4.7 years. The miners had an average peak oxygen consumption 2.9 ± 0.5 l.min-1, corresponding to 99.7 ± 20.4% of the predicted maximal oxygen consumption. Physical fitness of lignite miners was com-parable with reference values for healthy men in Czech population. The level of physi-cal fitness did not correlate with the length of exposure to underground work.
The present study was performed in 307 women, aged 25 to 55 years (mean 42.7 ± 4.7). The control group included 70 women, aged 42.1 ± 3.5 years, who had pre-viously had no contact with CS2. The study group included 237 women, age 42.9 ± 5.1 years, chronically exposed to 5 to 7 ppm level of CS2, monitored daily using a spectro-photometric method. It was found that quantitative abnormalities in the lipid fractions of blood in women chronically exposed to CS2 appear after the age of 39 years. They were manifested by a significant increase in the serum levels of total cholesterol and LDL-Ch, and a decrease in HDL-Ch. No differences were noted as to the concentration of free fatty acids between both groups.
To assess the degree of noise pollution in relation to the health and safety of the employees and commuters, a study on the levels of noise originating from various locomotives and also from different other sources was undertaken at Kalupur railway station of Gujarat State in India. The sound pressure levels (SPL) were measured on platforms. Noise dose count was monitored on a ticket collector on duty for 8 h. The results reflected that the SPLs in the platforms well exceeded the day time noise expo-sure limit. Further, the SPLs produced by loudspeakers were high and those by train whistles were intensely high pitched. The noise dose count of the ticket collector was also in excess of ACGIH standard. All these suggest that the SPLs in the platforms can endanger the healthful living of the users. Suitable control measures have been suggested.