Kishi R, Harabuchi I, Ikeda T
… +2 more, Katakura Y, Miyake H
Br J Ind Med
· 1993 May · PMID 8507600
·
Full text
This study was designed to clarify the nature of effects of trichloroethylene (TCE) on the central nervous system, and to determine the critical concentrations in blood associated with specific behavioural changes. This...This study was designed to clarify the nature of effects of trichloroethylene (TCE) on the central nervous system, and to determine the critical concentrations in blood associated with specific behavioural changes. This was achieved by a follow up of the whole time course of TCE intoxication during and after exposure. The effects of a single four hour exposure to TCE on signalled bar press shock avoidance in rats were tested by methods previously applied to investigate the acute neurobehavioural effects of exposure to toluene. Even low exposure to TCE induced shock avoidance performance decrements in rats. Rats exposed to 250 ppm TCE showed a significant decrease both in the total number of lever presses and in avoidance responses at 140 minutes of exposure compared with controls. The rats did not recover their pre-exposure performance until 140 minutes after the exhaustion of TCE vapour. Exposures in the range 250 ppm to 2000 ppm TCE for four hours produced concentration related decreases in the avoidance response rate. No apparent acceleration of the reaction time was seen during exposure to 1000 or 2000 ppm TCE. The latency to a light signal was somewhat prolonged during the exposure to 2000 to 4000 ppm TCE. It is estimated that there was depression of the central nervous system with slight performance decrements and the corresponding blood concentration was 40 micrograms/ml during exposure. Depression of the central nervous system with anaesthetic performance decrements was produced by a blood TCE concentration of about 100 micrograms/ml. These results showed effects of TCE on the central nervous system that were considered to be a function of both the exposure concentration and the duration of exposure, which are closely related to the TCE concentration in blood.
Br J Ind Med
· 1993 May · PMID 8507599
·
Full text
Recently, the determination of S-phenylmercapturic acid (S-PMA) in urine has been proposed as a suitable biomarker for the monitoring of low level exposures to benzene. In the study reported here, the test has been valid...Recently, the determination of S-phenylmercapturic acid (S-PMA) in urine has been proposed as a suitable biomarker for the monitoring of low level exposures to benzene. In the study reported here, the test has been validated in 12 separate studies in chemical manufacturing plants, oil refineries, and natural gas production plants. Parameters studied were the urinary excretion characteristics of S-PMA, the specificity and the sensitivity of the assay, and the relations between exposures to airborne benzene and urinary S-PMA concentrations and between urinary phenol and S-PMA concentrations. The range of exposures to benzene was highest in workers in chemical manufacturing plants and in workers cleaning tanks or installations containing benzene as a component of natural gas condensate. Urinary S-PMA concentrations were measured up to 543 micrograms/g creatinine. Workers' exposures to benzene were lowest in oil refineries and S-PMA concentrations were comparable with those in smoking or nonsmoking control persons (most below the detection limit of 1 to 5 micrograms/g creatinine). In most workers S-PMA was excreted in a single phase and the highest S-PMA concentrations were at the end of an eight hour shift. The average half life of elimination was 9.0 (SD 4.5) hours (31 workers). Tentatively, in five workers a second phase of elimination was found with an average half life of 45 (SD 4) hours. A strong correlation was found between eight hour exposure to airborne benzene of 1 mg/m3 (0.3 ppm) and higher and urinary S-PMA concentrations in end of shift samples. It was calculated that an eight hour benzene exposure of 3.25 mg/m3 (1 ppm) corresponds to an average S-PMA concentration of 46 micrograms/g creatinine (95% confidence interval 41-50 micrograms/g creatinine). A strong correlation was also found between urinary phenol and S-PMA concentrations. At a urinary phenol concentration of 50 mg/g creatinine, corresponding to an eight hour benzene exposure of 32.5 mg/m3 (10 ppm), the average urinary S-PMA concentration was 383 micrograms/g creatinine. In conclusion, with the current sensitivity of the test, eight hour time weighted average benzene exposures of 1 mg/m3 (0.3 ppm) and higher can be measured.
Br J Ind Med
· 1993 May · PMID 8507598
·
Full text
Despite 200 years of efforts to regulate safety in this occupation, chimney sweeps have increased mortality from cancer, ischaemic heart disease, and respiratory disease. Mortality and incidence of cancer were examined i...Despite 200 years of efforts to regulate safety in this occupation, chimney sweeps have increased mortality from cancer, ischaemic heart disease, and respiratory disease. Mortality and incidence of cancer were examined in a cohort of 5542 Swedish chimney sweeps employed through their national trade union at any time between 1918 and 1980. Previous studies of this cohort found increased risks of ischaemic heart disease, respiratory disease, accidental deaths, and various neoplasms. By increasing follow up, we sought to increase the power of the study and examine disease time trends. Mortality analysis was extended 7.5 years to cover the period 1951-90; cancer incidence analysis was extended six years to cover the period 1958-87. New findings include increased incidence and mortality of prostate cancer (SMR 169, 95% CI 106-256, 22 observed) and increased incidence of total haematolymphatic cancers (SIR 151, 95% CI 106-209, 36 observed). When only the most recent follow up period was analysed, previously observed risks persisted for total lung cancer (SIR 178, 95% CI 99-293), oat cell lung cancer (SIR 240, 95% CI 103-472), bladder cancer (SIR 247, 95% CI 131-422), and oesophageal cancer (Obs/Exp = 2/1.1). Mortality from ischaemic heart disease (SMR 98, 95% CI 76-123) and respiratory disease (SMR 111, 95% CI 56-199) declined during recent follow up, although significant excess mortality remained during analysis of the entire study period (ischaemic heart disease SMR 128, 95% CI 112-145; respiratory disease SMR 159, 95% CI 115-213). In analyses of the entire study period, risks of ischaemic heart disease and lung, bladder, and oesophageal cancer were adjusted for smoking; oesophageal cancer was also adjusted for use of alcohol. All risks remained significantly raised. Exposure-response analyses showed significant positive associations between duration of employment and risks for mortality from lung, oesophageal, and total cancer. Chimney sweeps remain at increased risk for cancers of the lung, oesophagus, and bladder. Our study supports a casual role for exposure to chimney soot, which contains carcinogens including polycyclic aromatic hydrocarbons. Extended follow up of this cohort now shows increased risks of prostate and haematolymphatic cancers.
Choudat D, Triem S, Weill B
… +5 more, Vicrey C, Ameille J, Brochard P, Letourneux M, Rossignol C
Br J Ind Med
· 1993 May · PMID 8507597
·
Full text
From the registry of self employed workers living in Paris, a group of 105 dental technicians was studied to evaluate occupational exposure, to determine respiratory manifestations, and to investigate immune disturbances...From the registry of self employed workers living in Paris, a group of 105 dental technicians was studied to evaluate occupational exposure, to determine respiratory manifestations, and to investigate immune disturbances. Seventy one dental technicians (age range 43-68: group D), 34 dental technicians younger than 43 or older than 68 (group d), and 68 control workers (age range 43-66: group C) were investigated. The demographic characteristics and the smoking habits of the groups D and C did not differ significantly. The dental technicians often worked alone (43.7%) or in small laboratories without adequate dust control. The mean duration of their exposure was long (group D 34.0 (SD 8.4) years). The prevalence of respiratory symptoms did not differ between groups D and C except for the occurrence of increased cough and phlegm lasting for three weeks or more over the past three years (group D 16.9%, group C 2.9%, p < 0.007). The effect of cigarette smoking on respiratory symptoms and lung function was obvious. All mean values of lung function for dental technicians and controls were within normal limits. Significant decreases in all mean lung function values were found among smokers by comparison with non-smokers, however, and a positive interaction with occupational exposure was established. The x ray films of dental technicians (n = 102, groups D and d) were read independently by four readers and recorded according to the International Labour Office classification of pneumoconioses. The prevalence of small opacities greater than 1/0 was 11.8% with a significant increase with duration of exposure. The prevalence among dental technicians with 30 years or exposure or more was significantly higher (22.2%) than those with less than 30 years (3.5, p < 0.004). The prevalence of autoantibodies (rheumatoid factors, antinuclear antibodies, and antihistone antibodies) was not significantly different in the groups D and C. When positive, autoantibodies only occurred at low concentrations. This finding contrasts with previous reports on the occurrence of autoantibodies and even of connective tissue diseases in dental technicians. In conclusion, the study confirms an increased risk of pneumoconiosis among dental technicians. Moreover, there may be other lung disorders such as impairment of lung function especially in association with cigarette smoking.
Br J Ind Med
· 1993 May · PMID 8507596
·
Full text
A previous large medical survey of active and retired sheet metal workers with 20 or more years in the trade indicated an unexpectedly high prevalence of obstructive pulmonary disease among both smokers and non-smokers....A previous large medical survey of active and retired sheet metal workers with 20 or more years in the trade indicated an unexpectedly high prevalence of obstructive pulmonary disease among both smokers and non-smokers. This study utilised interviews with a cross section of the previously surveyed group to explore occupational risk factors for lung disease. Four hundred and seven workers were selected from the previously surveyed group on the basis of their potential for exposure to fibreglass and asbestos. Selection was independent of health state, and excluded welders. A detailed history of occupational exposure was obtained by telephone interview for 333 of these workers. Exposure data were analysed in relation to previously collected data on chronic bronchitis, obstructive lung disease, and personal characteristics. Assessment of the effects of exposure to fibreglass as distinct from the effects of exposure to asbestos has been difficult in previous studies of construction workers. The experienced workers studied here have performed a diversity of jobs involving exposure to many different types of materials, and this enabled exposure to each dust to be evaluated separately. The risk of chronic bronchitis increased sharply by pack-years of cigarettes smoked; current smokers had a double risk compared with those who had never smoked or had stopped smoking. The occurrence of chronic bronchitis also increased with increasing duration of exposure to asbestos. Workers with a history of high intensity exposure to fibreglass had a more than doubled risk of chronic bronchitis. Obstructive lung disease, defined by results of pulmonary function tests at the medical survey, was also related to both smoking and occupational risk factors. Number of pack years smoked was the strongest predictor of obstructive lung disease. Duration of direct and indirect exposure to welding fume was also a positive predictor of obstructive lung disease. Duration of exposure to asbestos was significantly associated with obstructive lung disease but the dose-response relation was inconsistent, especially for those with higher pack-years of smoking exposure. Exposure to fibreglass was not a risk factor for obstructive lung disease.
Muir DC, Julian J, Jadon N
… +5 more, Roberts R, Roos J, Chan J, Maehle W, Morgan WK
Br J Ind Med
· 1993 May · PMID 8507595
·
Full text
Radiographs from 745 nickel sinter plant workers were taken and classified by five readers using the International Labour Office (1980) protocol. Each reader worked independently and the films were randomly mixed with fi...Radiographs from 745 nickel sinter plant workers were taken and classified by five readers using the International Labour Office (1980) protocol. Each reader worked independently and the films were randomly mixed with films from a non-dust exposed office population and also with films from subjects known to have silicosis or asbestosis. The prevalence of small irregular opacities was selected as the outcome of interest. In the sinter workers this was within the range identified in cigarette smokers or in workers exposed to dusts of low fibrogenicity. Only minimal evidence of small round opacities was noted. There was no evidence from the chest radiographs that exposures to high concentrations of dusts containing compounds of nickel caused an inflammatory or fibrogenic response in the lungs of the exposed population.
Chinn DJ, Cotes JE, Fechner M
… +1 more, Elliott C
Br J Ind Med
· 1993 May · PMID 8507594
·
Full text
BACKGROUND: A study was conducted to find out if pre-employment lung function at age 16 improved the estimation of that between ages 25 to 27 compared with the use of reference values based on smoking history, stature, b...BACKGROUND: A study was conducted to find out if pre-employment lung function at age 16 improved the estimation of that between ages 25 to 27 compared with the use of reference values based on smoking history, stature, body mass index, and other concurrent anthropometric variables. METHODS: Apprentices attending a shipyard training school were assessed on six occasions from entry during their 17th year to age 25 to 27; results for 114 such men were analysed. The measurements were of stature, body mass, fat free mass and body fat, thoracic dimensions, forced expiratory volume and indices of forced expiratory flow, total lung capacity, and its subdivisions, transfer factor and KCO. RESULTS: At best about half the variance in the final lung function could be accounted for with the concurrent reference variables. For each lung function index the proportion of explained variance was substantially increased by also including in the prediction equation the pre-employment lung function expressed in standard deviation units. CONCLUSION: Estimation of the longitudinal decline in lung function during adult life should be based on initial and final measurements of which the first should ideally be at age 25 but those at age 16 can be used instead: such measurements have long term value and should be preserved.
Br J Ind Med
· 1993 May · PMID 8507593
·
Full text
The first Chair of Occupational Health in the United Kingdom was established by Manchester University in 1945 and held by Ronald Lane, a consultant physician and experienced factor doctor. In his department, occupational...The first Chair of Occupational Health in the United Kingdom was established by Manchester University in 1945 and held by Ronald Lane, a consultant physician and experienced factor doctor. In his department, occupational medicine was taught as a clinical discipline to both undergraduates and postgraduates. Research was based mostly on clinical observation of workpeople in the field or as hospital outpatients. Although work has become less hazardous, with major risks like pneumoconiosis and lead poisoning brought under control by better occupational hygiene and more effective epidemiology, there is still much work related illness and injury. Promoting occupational health in its broadest sense still depends on clinical skills to assess fitness for work and to identify responses to adverse factors in the environment. A university department, through its teaching and research, needs to ensure that occupational health is practised as a clinical discipline. Opportunities for research are extensive and include: (1) identifying the extent and severity of injury and illness due to adverse environmental agents and psychosocial factors; (2) assessing fitness among the disabled and the elderly in an aging population enabling them to be gainfully or otherwise employed, (3) improving techniques for measuring work exposures and human responses to adverse work factors, and (4) evaluating intervention procedures. To fulfil its teaching and research commitments, an occupational health department has to maintain contacts with other disciplines in the university and with the industrial world outside. Isolation can be fatal. Academic departments of occupational health offer information to employers, trade unions, and health professionals seeking advice on health and safety problems. Such an Information and Advisory service provides topics for research and earns an income. It should not become the main activity otherwise teaching and research will suffer.
Daniell W, Stebbins A, O'Donnell J
… +2 more, Horstman SW, Rosenstock L
Br J Ind Med
· 1993 Apr · PMID 8494777
·
Full text
A cross sectional study to evaluate symptom reporting and neuropsychological test performance among a cohort of car body repair workers (n = 124) was performed using a computer-administered test system. Subjects with hig...A cross sectional study to evaluate symptom reporting and neuropsychological test performance among a cohort of car body repair workers (n = 124) was performed using a computer-administered test system. Subjects with high and medium current exposures to solvent and paint (n = 39 and 32), and low exposure subjects who formerly painted (n = 29) reported significantly more acute and chronic neurological symptoms than did low exposure subjects with no history of painting (n = 24). Subjects with higher current exposure performed significantly less well on selected tests of visual perception and memory, but there were no significant exposure related differences in mood state, motor speed, or visuomotor performance. The exposure related effects were most noticeable among subjects 35 years or older. The findings are consistent with age interactive central neurotoxic effects of current exposure to solvents or of cumulative past exposure, although the study is unable to distinguish between these possibilities. The computer administered test system was effective in this field based investigation involving multiple, geographically dispersed worksites.
Br J Ind Med
· 1993 Apr · PMID 8494776
·
Full text
Temporary threshold shifts (TTSs) in vibrotactile perception produced by continuous vibration and repetitive shock have been investigated. Subjects were exposed to vertical hand-transmitted 100 Hz continuous vibration an...Temporary threshold shifts (TTSs) in vibrotactile perception produced by continuous vibration and repetitive shock have been investigated. Subjects were exposed to vertical hand-transmitted 100 Hz continuous vibration and various repetitive shocks of equal energy content formed from one complete cycle of a 100 Hz sine wave. The repetition rate of the cycles was 5, 25, 50, or 100 s-1 while the root-mean-square (rms) acceleration measured over exposures of five minutes was held constant at 2.5, 5, or 10 ms-2 rms (weighted according to British Standard (BS) 6842 and International Standard (ISO) 5349). A control condition with no vibration was also included. Subjects held a handle with 10% of their maximum hand grip force. When exposed to five shocks per second at each of the three frequency-weighted acceleration magnitudes the subjects developed a small TTS. Exposure to 100 shocks per second (continuous vibration) at each of the three frequency-weighted acceleration magnitudes caused a large TTS, although the total frequency-weighted energy was the same as when exposed to five shocks per second. The relation between the TTS, the logarithm of the shock repetition rate, and the logarithm of the frequency-weighted rms acceleration was described by the relation TTS = -16.256 + 11.812 log10 R + 15.179 log10 ahw, where TTS is the temporary threshold shift, R is the shock repetition rate, and ahw is the frequency-weighted rms acceleration according to BS 6842 and ISO 5349. The results suggest that the equal energy hypothesis underlying BS 6842 and ISO 5349 is inappropriate for the prediction of the TTS produced by repetitive shocks.
Br J Ind Med
· 1993 Apr · PMID 8494775
·
Full text
In a population based case-control study of kidney cancer in New South Wales, data from structured interviews with 489 cases of renal cell cancer (RCC), 147 cases of renal pelvic cancer (CaRP), and 523 controls from the...In a population based case-control study of kidney cancer in New South Wales, data from structured interviews with 489 cases of renal cell cancer (RCC), 147 cases of renal pelvic cancer (CaRP), and 523 controls from the electoral roles were obtained about employment in certain industries or occupations, and exposure to particular chemicals chosen because of suspected associations with kidney cancer. A low level of education increased the risk for CaRP but not RCC. After adjustment for known risk factors, exposure to asbestos significantly increased the risk for RCC (relative risk (RR) = 1.62; 95% confidence interval (95% CI) 1.04-2.53). Working in the dry cleaning industry had a stronger link with CaRP (RR = 4.68; 95% CI 1.32-16.56) than with RCC (RR = 2.49; 95% CI 0.97-6.35). Working in the iron and steel industry doubled the risk for CaRP (RR = 2.13; 95% CI 1.04-4.39) whereas employment in the petroleum refining industry had a non-significant association with CaRP (RR = 2.60; 95% CI 0.88-7.63) and none with RCC.
Br J Ind Med
· 1993 Apr · PMID 8494774
·
Full text
For the purpose of assessing the human carcinogenic potential of the chlorophenoxy herbicides MCPA, MCPP, and 2,4-DP, the relevant epidemiological and toxicological evidence is reviewed. These compounds have not produced...For the purpose of assessing the human carcinogenic potential of the chlorophenoxy herbicides MCPA, MCPP, and 2,4-DP, the relevant epidemiological and toxicological evidence is reviewed. These compounds have not produced tumours in animal studies conducted under current test guidelines, giving no reason to predict that they would be carcinogenic to humans. Epidemiological studies have been conducted on three continents; greater emphasis is placed on the studies reported from western Europe, however, as this has been the area of more use. Although several of these studies provide suggestive evidence of associations between exposure to chlorophenoxy compounds and increased risks for some uncommon cancers, it is inconsistent and far from conclusive. None of the evidence specifically implicates MCPA, MCPP, or 2,4-DP as human carcinogens.
Br J Ind Med
· 1993 Apr · PMID 8494773
·
Full text
An assessment has been made of biochemical alterations in renal and hepatic functions of 73 male operators employed for an average of 8.2 years (range 0.5-23 years) in a chemical plant producing chlorinated hydrocarbons....An assessment has been made of biochemical alterations in renal and hepatic functions of 73 male operators employed for an average of 8.2 years (range 0.5-23 years) in a chemical plant producing chlorinated hydrocarbons. Exposure to allyl chloride (AC), 1,3-dichloropropene (DCP), epichlorohydrin (ECH), and hexachlorocyclopentadiene (HEX) has regularly been determined by personal air monitoring since 1980. Although exposures to DCP and ECH were well below currently accepted maximum allowable concentrations (MACs), relatively high exposures to AC and HEX, occasionally exceeding the MAC, have been measured. The results of the kidney and liver function tests were compared with those of a control group comprising 35 men employed at the materials division and not occupationally exposed to chemicals. Biochemical alterations of liver function were assessed by determination in serum of alanine and aspartate aminotransferases (ALAT, ASAT), alkaline phosphatase (AP), total bilirubin (BIL), gamma-glutamyltranspeptidase (GGT), lactate dehydrogenase (LDH), and total bile acids (SBA). No differences between the exposed group and the control group were found. Nor were differences found in biochemical tests for renal tubular damage (urinary alanine aminopeptidase (AAP) and N-acetyl-beta-D-glucosaminidase (NAG) and renal tubular function (urinary retinol binding protein (RBP). Total urinary protein and albumin excretion were measured to assess the integrity of the glomerulus. Urinary total protein did not differ between the groups, but urinary albumin, although within normal limits in both groups, was significantly higher (p < 0.02) in the exposed group. This difference in urinary albumin could not simply be explained by exposure to chlorinated hydrocarbons because albumin concentrations did not correlate with the duration of employment. It is concluded that long term exposure to concentrations of AC, DCP, ECH, or HEX below or near the current limit threshold value does not lead to clinically significant effects on kidney and liver.