Ethical issues among Finnish occupational physicians and nurses.

A postal survey was conducted among 200 Finnish occupational physicians and nurses on their ethical values and problems. Both groups considered 'expertise' and 'confidentiality' as the most important core values of occupational health services (OHS) corresponding with newly published national ethical guidelines for occupational physicians and nurses in Finland. Nearly all respondents had encountered ethically problematic situations in their work, but ethical problems with gene testing in the near future were not considered likely to occur. Only 41% of the nurses and 36% of the physicians had received some training in the ethics of OHS, and 76% of all respondents never used available ethical guidelines. According to the results, even if ethics play a vital role in OHS, the ability to critically evaluate one's own performance seems quite limited. This creates a need for further training and more practicable national guidelines.

Implementation of a quality system for the examination of occupational diseases.

A quality system in accordance with the principles of the ISO 9004-2 standard has been implemented at a department examining patients with occupational diseases. The quality system is the organizational structure needed to implement total quality management (TQM). The purpose of the system is to ensure that everyone is aware of the common quality objectives and knows how to achieve them. The quality system involves participation, training and guidelines and is based on customers' satisfaction and fluency of the activities. When the duration of the completed examinations was used as a measure of the fluency, this study demonstrated that TQM is feasible in health care. The fluency increased spontaneously due to increased awareness of rapidity as one of the quality characteristics and better understanding of the entire work process. This practical approach seems to be a good way to build up the basic quality and to motivate the personnel.

Role of occupational exposure to airway irritants in the development of asthma.

In order to study the role of occupational exposure in the etiology of asthma, 78 asthmatics and 56 nonasthmatics from the Finnish twin cohort were investigated by means of a postal questionnaire. Among those studied were 31 identical twin pairs discordant with regard to asthma (i.e., only one member of the pair had asthma). The questionnaire inquired into the diagnosis and status of the asthma, smoking habits, atopic background, smoking history of the parents, and history as regards pets, and requested a detailed description of occupational exposure to airway allergens and irritants. Classification into asthmatics and nonasthmatics was based on the information gathered with the questionnaire, supplemented by other information whenever possible. Estimation of exposure was based on the subject's own report, on the work descriptions, and on the general knowledge about the exposure levels associated with work tasks in question. Exposure to organic solvents was found only in the asthmatic members of the discordant pairs, and none of the nonasthmatic persons had been exposed to solvents. There were no statistically significant differences as regards exposure to other unspecific irritants. Combined exposure to organic allergens and airway irritants was more common in the asthmatics than in the nonasthmatics (P = 0.009). Exposure to irritants was also more common among the asthmatics than the nonasthmatics with similar exposure to organic allergens (P = 0.004).

Exposure to organic solvents and neuropsychological dysfunction: a study on monozygotic twins.

Twenty one monozygotic twins exposed to organic solvents were compared with their non-exposed cotwins by performance in psychological tests. A further 28 monozygotic twin pairs were examined as a reference group. The study used 11 tests, 10 of which had shown an effect in previous studies on the results of exposure to solvents. Paired comparisons of the test scores showed the exposed twins to have lower performance in associative learning, digit span, and block design. These results agree with two previous studies that used a similar set of tests. Contrary to some other studies, psychomotor speed was not affected, but the results indicated a marginal effect on the control of hand movements. Further comparison of subgroups with a low and a high exposure showed the prevalence of subtle neuropsychological dysfunction to be greater among the more exposed twins.

Cardiac arrhythmias during occupational exposure to fluorinated hydrocarbons.

The effects of occupational exposure to chlorodifluoromethane (FC 22) and dichlorodifluoromethane (FC 12) on cardiac rhythm were examined. The subjects were six men who repaired refrigerators (age 31-56, mean 46 years) and a control group of six plumbers (age 29-54, mean 45 years). Ambulatory electrocardiograms (ECG) were recorded for 24 hours on the day of exposure and on a control day. The ECG tapes were automatically analysed with a Reynolds pathfinder 3 apparatus and all aberrant complexes recorded by the machine were checked. One person read all the tapes without knowing whether or not they were recorded during exposure. The number of ventricular ectopic beats were compared between the day of exposure and the control day and with the tape of the control. In addition, the number of ventricular ectopic beats during exposure was compared with the number occurring during the rest of the day. The concentrations of fluorocarbons were measured in four instances. High peak concentrations of fluorocarbons (1300-10,000 cm3/m3) were measured during refrigerator repair work. No clear connection between fluorocarbons and cardiac arrhythmia was found, although one subject had several ventricular ectopic beats which may have been connected with exposure.

Multiple sclerosis and occupational exposure to chemicals: a co-twin control study of a nationwide series of twins.

From the Finnish Twin Cohort (n = 27,100 pairs with known zygosity) all cases of diagnosed multiple sclerosis (MS) were reviewed and those with clinically verified MS were invited for further examinations at the Institute of Occupational Health, Helsinki, with their co-twins. Twenty one cases (19 pairs, of which 17 were discordant) fulfilled the strict criteria of MS. Detailed occupational history showed exposure to a mixture of solvents in six subjects, to lead in one, and to trichloroethylene in one. Of these seven, two monozygotic twins had MS whereas the other five cases were healthy co-twins. These results do not support a causal association between occupational exposure to chemicals and the aetiopathogenesis of MS.

Occupational exposure to solvents and cerebellar, brainstem and vestibular functions.

Forty-eight persons (age 44, SD 9 years) exposed to paint solvents and 40 nonexposed referents (age 45, SD 9 years) were examined. The duration of exposure was 4 to 30 (mean 20) years and the life-time exposure level was estimated to have been 10 to 330 (mean 60%) of the hygienic standard. The methods used were a neurological examination, electroencephalography, brainstem auditory-evoked potentials, electronystagmography, and posturography. Life-time exposure was estimated on the basis of a detailed occupational history and environmental measurements made at the work places over several years. The average weekly alcohol consumption was established in a detailed interview. Due to the small number of subjects examined, the study was inconclusive. The findings classified as abnormal were slightly more common in the exposed than in the referents, and in the persons who used alcohol than in the non-users. The differences were not statistically significant, and no exposure-response relationships were found.

Cardiovascular reflexes in monozygotic twins discordant for exposure to organic solvents.

Eighteen pairs of monozygotic twins discordant for long-term occupational exposure to organic solvents were examined for disturbances of cardiovascular reflexes. All of the subjects were asymptomatic, and considered themselves healthy. No significant differences were observed between the exposed and the nonexposed twins. The finding suggests that occupational solvent exposure at these particular levels is unlikely to cause disturbances of the autonomic nervous function.

Psychological performance, toluene exposure and alcohol consumption in rotogravure printers.

A psychological test battery was administered to a group of 43 rotogravure printers exposed to toluene (mean age 41 years, mean duration of exposure 22 years) and to a referent group comprising 31 offset printers of the same age. Eighteen of the rotogravure printers and one of the referents were heavy drinkers of alcohol. The test battery included tests for verbal and visual cognition and memory, perceptual motor speed, and psychomotor abilities. A vocabulary test (Synonyms) was used as a measure of initial intelligence. Performances in the two groups were compared, and descriptive data analyses were made in four subgroups formed according to toluene exposure and drinking habits. The rotogravure printers performance was inferior to the referents in tests measuring visual cognitive abilities. The mean test performances in the subgroups indicated that the difference in drinking habits did not explain the differences: the heavy drinkers tended to perform better than those with more moderate drinking habits. An antagonistic interaction between toluene and alcohol was suggested by intact performances among the heavy drinkers with high exposure (n = 8). The question deserves to be investigated further.

Nervous system effects of long-term occupational exposure to toluene.

Forty-three male rotogravure printers with long-term toluene exposure and 31 age- and sex-matched offset printers without toluene exposure were examined in detail. Clinical, neurophysiological, neuropsychological and neuroradiological examinations and assessment of autonomic functions did not reveal any statistically significant differences between the groups. The results suggest that occupational long-term exposure to toluene under these circumstances does not have clinically significant adverse effects on the nervous system. Exposure to toluene seemed to be associated with heavy drinking.

Occupational exposure to toluene: neurotoxic effects with special emphasis on drinking habits.

Neurotoxic effects of toluene were examined in 43 male rotogravure printers exposed to toluene (age 27-63, mean 41 years; duration of exposure 11-40, mean 22 years) and 31 male offset printers of the same age with slight exposure to aliphatic hydrocarbons. A neurological examination, tests for autonomic nervous function, electroencephalography, psychological tests and computerized tomography of the brain were carried out in addition to a standardized interview. Exposure levels were evaluated for each person separately on the basis of his work history and the results of an earlier study on exposure levels at the same printing shops. Besides a thorough history of alcohol consumption, information about the printers' drinking habits was obtained from the occupational health care centers of the printing shops. The examinations found only slight abnormalities, and there were no statistically significant group differences in the prevalences of abnormalities. No correlations between the abnormalities and the exposure indices were found either. One of the retired workers, however, who had been exposed to high toluene concentrations for over 40 years, had been diagnosed as having chronic organic solvent intoxication. Heavy drinkers of alcohol were clearly more common in the toluene-exposed group. This study detected no clinically significant abnormalities attributable to toluene alone among workers exposed to 68-185 ppm (mean 117) of toluene for over 10 years. The connection between alcohol consumption and toluene exposure is interesting and deserves further study.

Time course of electrophysiological findings for patients with solvent poisoning. A descriptive study.

The time course of electroencephalographic (EEG) and electroneuromyographic (ENMG) findings was studied among 87 patients (40 men and 47 women) with a diagnosis of chronic solvent intoxication after occupational exposure. Neurophysiological studies were initially performed around the time of diagnosis, and all the patients were reexamined three to nine years later. No control group was available for the follow-up. Upon diagnosis 67% of the patients had an abnormal EEG, the majority with diffuse slow-wave abnormalities. The reexamination showed improvement in the EEGs of 47%, but the percentage of patients with paroxysmal abnormalities had increased from the initial 6 to 17. The percentage of patients with neuropathic findings was 62 for the first and 74 for the second ENMG. Upon reexamination fibrillations were seen in 46% (in 38% in the initial examination), and some loss of motor units was found for 61% (for 54% in the initial examination). Mild improvement in the neuropathic findings was noted for 60%, but the neuropathic findings of 25% showed slight deterioration during the follow-up period. The EEG findings showed a time course resembling that described after external head injuries. The ENMG findings resembled those described in hexa-carbon-induced or carbon disulfide-induced neuropathy. Controlled studies are recommended to examine the observed slight associations between electrophysiological findings and the type of chemical exposure.

Psychological prognosis of diagnosed chronic organic solvent intoxication.

The psychological prognosis of 86 patients (40 men and 46 women) with previously diagnosed chronic solvent intoxication due to trichloroethylene, perchloroethylene, or solvent mixtures was studied after a follow-up period (mean 5.9 years). The patients' mean age at the time of diagnosis was 38.6 years, and the mean duration of solvent exposure was 10.7 years. Tests for intelligence, short-term memory, and sensory and motor functions were applied. The group means of the patients' intellectual functions were increased after the follow-up period. At the group level, the scores on one sensorimotor task and tasks requiring manual dexterity were lower. Individual patients performed better, worse, or equally when the results of the initial examination and the reexamination were compared. The overall prognosis of psychological test results was better with a longer follow-up period and lower age. Patients who used drugs with neurological effects had a poorer overall psychological prognosis. The characteristic of solvent exposure were related only to the prognosis of some single tests for sensory and motor functions.

Clinical prognosis of patients with diagnosed chronic solvent intoxication.

The clinical symptoms and signs of 80 patients with chronic organic solvent intoxication were evaluated after 3-9 years (mean 5.8 years) of follow-up. Thirty-one of the patients had slight clinical neurological signs at the time of diagnosis while the rest of the patients had only neurophysiological or psychological disturbances. The most common subjective symptoms were headache, tiredness and memory disturbances. Of the clinical signs, disturbances occurred frequently in cerebellar functions, gait and station and fine motorics. In addition, psycho-organic alteration and neurasthenic signs were often found. After the follow-up clinical signs of impairment in the nervous system were present in 42 cases. At the group level, the subjective symptoms decreased during the follow-up but the objective clinical signs increased and worsened. Only the prognosis of disturbances in gait and station correlated with the duration and intensity of exposure. The present results emphasize the great difficulties arising in occupational neurology regarding chronic organic solvent intoxications. No clear-cut clinical picture exists and reliable estimation of prognosis in general cannot be made on the basis of the present knowledge.