[Occupational exposure to harmful materials in artistic activities]. / Profesionalne stetnosti u djelatnosti likovnih umjetnika.

Artists' activities such as sculptures, paintings, graphic designs, photography, restoration, glassblowing, glass cutting and ceramics are described. The hazards the artists are exposed to during their professional activities with potential dangerous effects on their health are listed. Diseases which can develop as a consequence of exposure to specific noxious agents in such in environment are described. Preventive measures (personal, technical and medical) which should be applied in order to prevent the development of diseases related to these specific working conditions are stressed.

Study of some immunological parameters in workers occupationally exposed to benzene.

OBJECTIVE: The aim of the study was to investigate the immunotoxicity of benzene exposure, to establish the correlation between the exposure biomarkers and some immunological parameters, and to assess the possible influence of confounding factors on the results of immunological assay applicable in routine medical surveillance of benzene-exposed workers. METHODS: Forty-nine female workers in the shoemaking industry who were exposed to solvent mixtures and 27 nonexposed controls were examined. Workers were exposed to benzene concentrations of up to 15 ppm, and to toluene of up to 50 ppm. RESULTS: Significant differences in the levels of benzene and toluene in blood and phenols in post-shift urine between the exposed and the control group confirmed solvent exposure. The number of B-lymphocytes (P = 0.01) was lower in the shoe workers than in the controls. Significant correlation was found between the level of immunoglobulin G and benzene in the work atmosphere, while confounding factors had no impact on immunological values. CONCLUSION: According to these results, exposure to benzene concentration lower than 15 ppm can induce depression of the circulating B-lymphocyte level and therefore this fact could be used to develop a promising method for health surveillance of benzene-exposed workers. However, considerably more effort in the research on benzene immunotoxicity, especially in the search for suitable health surveillance methods, is still required.

[Specificity of diagnostic procedures in occupational diseases]. / Specificnosti dijagnostickih postupaka kod profesionalnih bolesti.

Characteristics and specificities of diagnostic procedures as a basis of diagnosis of occupational diseases are explained. The aforementioned include working history, clinical, laboratory and functional tests and evaluation of working environment. Examples of practical application of such procedures are listed.

Assessment of colour vision impairment in male workers exposed to toluene generally above occupational exposure limits.

We investigated colour vision impairment in 45 male workers occupationally exposed to toluene (mean value of toluene concentration in ambient air = 119.96 ppm) and in 53 controls. Colour vision was evaluated by Lanthony-D-15 desaturated test and expressed as Age and Alcohol Intake Adjusted Colour Confusion Score (AACDS) or types of dyschromatopsia. Exposure was evaluated by measurement of toluene concentration in ambient air and blood, and hippuric acid and orthocresol determined in urine after the workshift. A statistically significant higher AACDS value was established in the exposed subjects compared to the controls (p < 0.0001). There was no significant difference between AACDS values on Wednesday morning compared to Monday morning. In the exposed group AACDS significantly correlated with the concentration of toluene in ambient air, concentration of toluene in blood and the concentration of hippuric acid in urine after the workshift (all p < 0.0001). Dyschromatopsias were detected in both groups, although no significant difference between groups was established. In the exposed group concentration of toluene in ambient air, alcohol intake and age explained 35.1%, concentration of toluene in blood, age and alcohol intake explained 19.9%, and concentration of hippuric acid in urine and age explained 19.2% of the variation in type III dyschromatopsia. Concentration of toluene in ambient air and age explained 28.3% of the variation in total dyschromatopsia, and concentration of hippuric acid and age explained 13.8%. In the control group, age and alcohol intake explained 19.6% of the variation in type III dyschromatopsia. In exposed workers a significant difference was found in the AACDS value compared to controls. However, no significant difference was found in the prevalence of colour vision loss in the yellow-blue and/or red-green axis. Based on the results of this study the authors conclude that the effect of toluene on colour vision can be chronic and that the possible reparation period in colour vision impairment is longer than 64 hours.

Qualitative color vision impairment in toluene-exposed workers.

OBJECTIVE: The aim of this study was to evaluate whether toluene, like many other organic solvents and solvent mixtures, could impair color vision. SUBJECTS AND METHODS: We investigated color vision impairment in three groups of workers, two groups occupationally exposed to toluene and a nonexposed group. The first exposed group, group E1, comprised 41 workers (median value of toluene in air 35.00 ppm, range 11.3-49.3 ppm) and the second exposed group, group E2, comprised 32 subjects (median value of toluene in air 156.00 ppm, range 66.0-250.0 ppm). The nonexposed group, group NE, comprised 83 subjects. Color vision was evaluated by the Lanthony D-15 desaturated test according to Verriest's classification: type I, loss in the red-green range; type II, loss in the blue-yellow and red-green ranges, and type III, loss in the blue-yellow range. Subjects were classified as dyschromates if specific acquired loss was determined in at least one eye. In both exposed groups, exposure was evaluated by measurement of the concentration of toluene in the ambient air and in the blood. In group E2, level of hippuric acid and orthocresol in urine after the work shift were also determined. The Mann-Whitney U-test, t-test, chi 2-test, and Spearman's rank correlation and multiple regression analysis were used for statistical analysis. RESULTS: Type III dyschromatopsia was detected in all groups examined: 26.6% of the workers in group NE, 31.7% of those in group E1, and 50% of those in group E2. As many as 15.6% of the workers in group E2, 4.8% of those in group E1, and only 1.2% of those in group NE had type II dyschromatopsia. A statistically significant difference in the prevalence of total dyschromatopsia (type III + type II) was established among the three examined groups together (chi 2 = 14.13; df = 2; P < 0.01), between group E2 and group E1 (chi 2 = 4.96; P < 0.05), and between group E2 and group NE (chi 2 = 12.50; P < 0.005), whereas no significant difference was found between groups E1 and NE. Type III dyschromatopsia was significantly correlated with age in group NE (P < 0.01) and in group E1 (P < 0.005). In group E2, both type II (P < 0.05) and type III dyschromatopsia correlated with toluene in ambient air and with the duration of exposure to toluene (both P < 0.005). In group E2, total dyschromatopsia correlated significantly with toluene in ambient air and in blood (both P < 0.05) as well as with hippuric acid in urine after the work shift (P < 0.001). CONCLUSION: This study suggests that toluene can impair color vision.

Quantitative assessment of color vision impairment in workers exposed to toluene.

Color vision was examined by the Lanthony-D-15 desaturated test in two groups of workers occupationally exposed to toluene and in a control group. Biological parameters of toluene exposure were analyzed: toluene in air and in venous blood, orthocresol, and hippuric acid in urine after workshift. The first exposed group, Group E1, comprised 41 workers (toluene exposure ranged from 11.30 to 49.30 ppm), and the second exposed group, Group E2, comprised 32 workers (toluene exposure ranged from 66.00 to 250.00 ppm). The nonexposed group, Group NE, comprised 83 subjects. Each group was divided into two subgroups; alcohol consumers and nonconsumers. Color vision loss was expressed as a color confusion index (CCI) and as age and alcohol intake-adjusted color confusion index (AACCI). Significantly higher values of CCI and AACCI (both P < 0.0001) in Group E2 in comparison to Group NE, and significantly higher CCI (P < 0.0001) and AACCI (P < 0.05) values in Group E2 in comparison to Group E1 were established. The significant difference in CCI value between alcohol consumers and nonconsumers was established only in Group NE (P < 0.05). In Group NE significant correlation was found between CCI value as a dependent and age and alcohol intake as independent cofactors (R2 = 0.45; P = 0.0000). In Group E2 significant correlation was established between CCI as a dependent factor and age, toluene in air, and alcohol intake (R2 = 0.72; P = 0.0001), or between CCI as dependent and age, toluene in blood and alcohol intake as independent cofactors (R2 = 0.68; P = 0.0002). In Group E1 significant correlation was established only between CCI and age (P <0.005). In Group E2, AACCI value significantly correlated with toluene in air (P < 0.0001), toluene in blood (r < 0.0005), orthocresol (P < 0.005) and hippuric acid (P < 0.005) in urine after workshift. There were no differences between smokers and nonsmokers in CCI values in the examined groups. Results of this study indicate that toluene in exposed workers can impair color vision. The role of alcohol intake and age influence on color vision loss cannot be ignored in such workers.

Red blood cell glycerol lysis and hematologic effects in occupational benzene exposure.

Forty-nine female workers in the shoemaking industry, exposed to a solvent mixture containing benzene and twenty-seven non-exposed controls, were investigated. Concentrations of benzene and toluene in the working atmosphere, as well as benzene and toluene in blood and phenols in pre- and post-shift urine as parameters of biological monitoring, were determined. In order to assess hematotoxic risk, a complete blood cell count with differential, hemoglobin, hematocrit, mean corpuscular volume, mean corpuscular hemoglobin, mean corpuscular hemoglobin concentration, reticulocytes, serum iron, alkaline phosphatase in neutrophils and red blood cell glycerol lysis time were determined in all subjects. Benzene concentrations in the workplace atmosphere at the shoemaking factory ranged from 1.9 to 14.8 ppm (median = 5.9). Significant difference in benzene in blood (p = 0.005) and phenol in post-shift urine (p = 0.003) between exposed workers and controls confirmed exposure to benzene. Hemoglobin level (p = 0.02) and mean corpuscular hemoglobin concentration (p = 0.0002) in the shoe workers were lower, and band neutrophils (p = 0.005) and mean corpuscular volume (p = 0.03) higher, than in controls. Red blood cell glycerol lysis time was significantly higher (p = 0.000001) in shoe workers (X +/- SD = 41.6 +/- 8.9) than in controls (X +/- SD = 31.1 +/- 6.5) and showed a significant correlation with exposure biomarkers. The results confirm that benzene exposure below 15 ppm may produce qualitative abnormalities, particularly macroerythrocytosis and increased red cell glycerol resistance, in the absence of an overt quantitative decrease in circulating blood cells. Increased resistance to the hemolytic action of glycerol is a potentially useful biological monitoring procedure in medical surveillance of benzene exposed workers. The results of this study suggest that potential threshold concentration for hematologic effects of benzene is lower than 15 ppm.

Genotoxic effects in workers exposed to benzene: with special reference to exposure biomarkers and confounding factors.

The aim of the study was to establish a correlation between biomarkers of exposure and cytogenetic test results in workers occupationally exposed to benzene and toluene, with special reference to confounding factors influencing the outcome of the cytogenetic test. The incidence of structural chromosome aberrations and sister chromatid exchanges was studied in the peripheral blood lymphocytes cell genome of 49 female shoe-makers, mean age 38 years, mean length of occupational exposure 17 years and in a group of 27 well-matched controls. Workers were exposed to concentrations of benzene up to 15 ppm and of toluene up to 50 ppm. The presence of benzene and toluene in the workers' blood samples, and the presence of phenol in pre- and post-shift urine were considered proof of occupational exposure. Chromosomal aberration analysis revealed a significant increase in dicentric incidence in the exposed group compared to the controls (P = 0.004). However, significant correlation between cytogenetic test results and the exposure biomarkers was not established. On the contrary, correlation between the cytogenetic test results and data on confounding factors (e.g. age and alcohol consumption), was marked. The major point raised by this study is the influence of confounding factors on the cytogenetic test outcome. This imposes the need for caution in the interpretation of cytogenetic test results, and ultimately in the estimation of individual genotoxicity risk related to low level benzene exposure.

Colour vision impairment in workers exposed to low concentrations of toluene.

Colour vision was examined by the Lanthony-D-15 desaturated test in 41 women exposed to toluene and in 29 non-exposed referents. Toluene exposure was evaluated by methods of environmental and biological monitoring. In the exposed group the median value of toluene in air was 35 ppm (range 11.2-49.9 ppm). Quantitative colour vision impairment was expressed as colour confusion index and colour confusion index corrected for alcohol intake. Qualitative impairment was expressed as normal, yellow-blue, red-green range or complex impairment. Statistical analysis showed the index values to be significantly correlated with age in both groups. In the exposed group they were significantly higher than in the non-exposed group. There was no significant difference in the prevalence of impairment in the blue-yellow range between the examined groups, although the prevalence of impairment in the exposed group was higher than in the non-exposed one. Results suggest that exposure to low toluene concentrations may induce colour vision impairment in women.

Medical surveillance studies of workers exposed to low level benzene.

The paper presents th results of an investigation of haematotoxicity in workers exposed to low benzene concentrations. Forty-seven female workers in the shoemaking industry, exposed to solvent mixture and twenty-seven non-exposed controls were examined. Benzene concentrations in the working atmosphere ranged from 1.9 to 14.8 ppm. Significant differences in the levels of benzene in blood and phenols in pre- and post-shift urine between the exposed and control groups confirmed benzene exposure. Haemoglobin level and mean corpuscular haemoglobin concentration were significantly lower, and mean corpuscular volume was higher in the shoemaking workers than in controls. In the subgroup of shoemaking workers exposed to benzene concentrations of 5 ppm or lower, no differences in haematological parameters were found. In conclusion, exposure to a benzene concentration lower than 5 ppm does not appear to produce an increased level of abnormal haematological outcomes detectable in routine medical surveillance. The results of the study corroborate the present maximum permissible concentrations (5 ppm) as a protective limit preventing the onset of haematotoxic non-leukemogenic effects of chronic benzene exposure.

[Criteria for diagnosis of occupational asbestosis of the pulmonary parenchyma and pleura]. / Kriteriji za priznavanje profesionalne azbestoze pulcnog parenhima i pleure.

The criteria for acknowledgement of occupational parenchymal asbestosis were set out in the List of Occupational Diseases of 1983, under paragraph 26. In spite of this, some occupational health specialists and invalidity committees acknowledge the disease only when it meets the criteria recommended in the Conclusions of a Workshop on Asbestosis, held in former Yugoslavia, although such criteria were never legally implemented. According to these criteria asbetosis of the lung is recognized only when parenchymal profusion is subcategory profusion is subcategory 2/1 and higher, or at least subcategory 1/1 with visible pleural plaques and/or bilateral calcifications. In the Department of Occupational Health of the Institute for Medical Research and Occupational Health in Zagreb chest X-rays were taken and examined in 350 workers occupationally exposed to asbestos. In 51 (15%) of the workers lung fibrosis was excluded (profession of the parenchyma was subcategory 0/-) and in 53 (15%) fibrosis of the parenchyma could not be excluded or confirmed on the basis of the X-rays. In the remaining 246 (70%) the X-rays demonstrated clearly visible fibrosis and, depending on the parenchymal profusion, the finding was classified as subcategory 0/1 - 2/1 and higher, i.e. in 9% of the workers subcategory 1/1 was accompanied by visible bilateral pleural plaques. According to the Criteria from the Conclusions of a Workshop, on the basis of parenchymal profusion, asbestosis of the lungs would have to be acknowledged in 4% of those examined, while in 9% of the workers with parenchymal profusion of subcategory 1/1 or 1/2 asbestosis could be acknowledged only if visible bilateral plaques or pleural calcifications were present. On the other hand, according to the List of Occupational Diseases, only 15% of the examined workers offered no ground for acknowledging occupational parenchymal asbestosis. In another 15% of the examination, by which parenchymal asbestosis could be confirmed or excluded. Asbestosis of the lungs is a disease sui generis which should, with a positive work history, always be recognized as an occupational disease, after other etiology of the parenchymal fibrosis has been excluded. The extent of parenchymal profusion, other asbestosis-related diseases and/or impaired ventilatory or diffusive function of the lungs are not decisive.

[Importance of risk assessment in occupational medicine]. / Znacenje procjene rizika u medicini rada.

The principles of risk assessment and its relevance in the working environment are discussed. Occupational health protection is a complicated process comprising risk assessment, health monitoring and eventually treatment of irreversible health effects. Risk assessment consists of the following four steps: hazard identification, dose-response assessment, exposure assessment and risk characterization. Although established for environmental protection, risk assessment is also used in occupational hazard identification and determination of priorities and risk management in occupational health and safety. In Croatia, the methodology of risk assessment is still undeveloped. The paper emphasises the role of occupational health in risk assessment and in implementation of the results of this complex process in the working environment.

[Acute neuroleptic poisoning]. / Akutna otrovanja neurolepticima.

According to the record of the Poison Control Centre in Zagreb, drugs most frequently implicated in poisoning episodes were benzodiazepines, neuroleptics, anticonvulsants including barbiturates, fluorides and antidepressants, which comprised more than 40% of all drug poisonings. More than 90% of neuroleptic poisonings were symptomatic on admission, 19% were comatose, 45% were drowsy, in 15% extrapyramidal symptoms were present, and only 9% were without symptoms. Severe poisonings in adults were almost all due to suicidal ingestion, while in children low to moderate doses of different neuroleptics caused severe poisoning in 13 cases, with coma, convulsions and most often with acute dystonic reactions. In 30 cases of neuroleptic ingestion more than one drug was involved. The usual combinations were with other neuroleptic or psychoactive drugs such as benzodiazepines, biperiden, carbamazepin and antidepressants. Therapeutic measures were gastric emptying in 32% of cases, biperiden when dystonia was present but only after consultation with the Centre and with 12-14 hours delay, and supportive treatment in all symptomatic patients.

Possible genotoxicity in low level benzene exposure.

Structural chromosome aberrations and sister chromatid exchanges (SCEs) in peripheral blood were studied in female workers employed in the shoe-making industry in two periods: 1987 (group I; N = 38) and 1992 (group II; N = 45). Only 11 of the workers were present in both groups and their results are presented both together and separately. Occupational exposure to benzene and toluene was confirmed through their determination in the working area, blood, and phenol in pre- and post-shift urine. The results were compared with those from the control group (N = 35). Benzene in the working atmosphere was significantly higher in 1987 compared to 1992, but was always lower than the current Croatian permissible concentration of 50 mg m-3 (in the near future this value will be changed to 15 mg m-3). A statistically significant difference was also found in biological markers of benzene exposure between the two periods of the investigation. Increased absorption in the first period occurred because of intensified production in 1987, and this decreased significantly in 1992 because of the war in Croatia. The cytogenetic study showed a significant increase in dicentric chromosomes in exposed groups I and II when compared to the control group. Statistically significant higher SCE frequencies were found in group I compared to the control group and also compared to group II. Between exposed group II and the controls no statistically significant difference in SCEs was found. Comparing the same 11 workers present in both periods the results showed no difference in chromosome aberrations between the two periods of examination. SCE frequencies were significantly higher in 1987 when greater benzene absorption occurred, confirmed by biomarkers of benzene exposure. The presented results indicate that genotoxicity may occur in workers exposed to low levels of benzene in the shoe industry.

Diagnostic value of finger thermometry and photoplethysmography in the assessment of hand-arm vibration syndrome.

Digital photoplethysmography and skin thermometry are both measures of circulation in the skin of the fingers. These methods and a cold provocation test were performed on 29 chain-saw workers grouped in stages 0, 1, 2, or 3 according to the Stockholm Workshop scale of hand-arm vibration syndrome, and on 16 controls. The reduction of photoplethysmographic amplitude after the cold test reflects the degree of vasoconstriction, and the recovery rate demonstrates passive vasodilatative capacity. Both tests were found to distinguish all vibration--exposed subjects, including those without clinically manifest vibration-induced white fingers, from the controls. With a 75% reduction in photoplethysmographic amplitude as a discriminating threshold, the sensitivity for the detection of Raynaud's phenomenon was 62% and the specificity, 87%. The discriminating threshold of 90% for recovery rate yielded a sensitivity of 69% and a specificity of 72%.

[Detection of changes in the microvasculature in systemic connective tissue diseases--report on methods]. / Detekcija promjena na mikrovaskulaturi kod sistemskih bolesti vezivnog tkiva--prikaz metoda.

The aim of the paper is to draw attention to the possibility of an early detection of microvascular changes in systemic connective tissue diseases by the serial application of capillaroscopy, dermothermometry and digital photophlethysmography. A detailed review of diagnostic methods as well as the description of own protocol of their application is presented.

[The effect of whole-body vibration: an unrecognized medical problem]. / Djelovanje opcih vibracija: nedovoljno poznat zdravstveni problem.

Exposure to whole-body vibration is a growing concern in industry, traffic and in other branches of the economy. This harmful physical factor endangers work efficiency and human health not only at work but also in everyday life, in public transportation and even at home. In spite of increasing exposure to vibrations, our medical practice does not pay adequate attention to the health effects of whole-body vibration. The paper deals with the basic characteristics of vibration (frequency, amplitude, velocity and acceleration), its adequate evaluation (effective or weighted average value, peak values, rating and weighting procedure of vibration measurement) and exposure (vibration direction, exposure time, transmission and dissipation). In industry and traffic, vibrations present complex oscillatory motions, characterized by a wide frequency spectrum, variable amplitude and acceleration, and different directions. To assess the harmful effects of vibration, the International Organization for Standardization (ISO) has proposed three standards for acceptable human exposure to whole-body vibration: fatigue-decreased proficiency boundary, exposure limit and reduced comfort boundary. Quantitative parameters of vibration for some vehicles, and for constructional, industrial and agricultural machinery are also given. The most pronounced long-term effect of whole-body vibration is damage to the spine. The spinal region most frequently affected is the lumbar part, where spinal deformation, lumbago and sciatica can develop. The possible cause of spinal damage could be mechanical overload and metabolic changes of the intervertebral disc. Other organ systems, such as peripheral and autonomic nervous, vestibular, vascular, digestive and female reproductive systems are also liable to become affected. Risk assessment of chronic health effects is based on the appropriate evaluation of whole-body vibration exposure and individual response. Health risk increases with the intensity and duration of vibration exposure. The concomitant factors are forced sitting posture and heavy physical work. Human response to whole-body vibration depends on factors promoting the development of degenerative changes such as constitution, previous spine disease and young age. The main problems in diagnosing whole-body vibration syndrome are differentiation of vibration induced disorders from age dependent changes of the spine and lack of a specific diagnostic method for assessing those changes. Therefore, only permanent medical surveillance can guarantee proper assessment of the damage induced by whole-body vibration. For vibration exposed workers preplacement and periodic examinations are recommended. Those should include a basic medical examination and an X-ray of the spine, or at least of its lumbar part.

Diagnostic value of finger thermometry in assessment of hand-arm vibration syndrome.

Finger thermometry and cold provocation test were performed in 90 chain saw workers and 58 healthy controls. The workers were grouped according to the Taylor-Pelmear scale of hand-arm vibration syndrome into subgroups 0, 1, 2, 3. The recovery rate reflected passive vasodilative ability. According to the results of the study, the test could differentiate the subjects with clinically manifest vibration-induced white fingers (stages 1, 2 and 3) from the controls. The discriminating threshold of recovery rate with regard to Raynaud's phenomenon was 90%. With that diagnostic limit the above method was sensitive and specific enough to verify vibration-induced vasospastic disorders and therefore could be recommended for their surveillance.

Lung functions and chest radiographs in shipyard workers exposed to asbestos.

Lung functions and diffusing capacity for carbon monoxide were examined in 299 shipyard workers occupationally exposed to asbestos, among whom there was an equal number of smokers and non-smokers. The workers were classified into groups according to the lung fibrosis profusion and the length and width of the pleural plaques in accordance with the 1980 ILO International Classifications of Pneumoconioses. With regard to the profusion of the parenchyma, workers classified in category 2 (subcategories 2/1 and 2/2) had significantly lower FVC and FEV1 values than the workers in categories 0 (P < 0.01) and 1 (P < 0.05). With an increase in the category of profusion there was a trend towards a fall in mean MEF25, MEF50 and MEF75 values, but it was not significant. Diffusing capacity for carbon monoxide was identical for all categories. There were no significant differences between the workers without pleural plaques and those with visible plaques in respect to lung function values. With an increase in the length and width of the plaques FVC, FEV1, MEF25 and MEF75 values tended to become lower. The results demonstrate that the changes detected on the radiographs of the lungs and pleura are the early indicators of possible asbestos disease in shipyard workers.

Digital photoplethysmography in the diagnosis of traumatic vasospastic disease.

By means of the photoplethysmographic method including the cold test, skin blood flow was recorded in the fingers of 42 chain-saw operators and 36 control subjects. The essential difference between the groups pertained to the height of the pulse wave amplitude after the cold test and to the fall in amplitude expressed as a percentage of its initial value. A limit of a 90% fall in amplitude after the cold test is proposed as a criterion for differentiating a normal from a pathological vasospastic reaction. A fall in amplitude is correlated with the intensity of subjective disorders, i.e. the attack of vibration-induced white fingers. The obstructive form and loss of amplitude of the pulse wave form are accepted as pathological.