Asbestos danger in central Europe is not yet over - the situation in the Czech Republic.

OBJECTIVES: In the Czech Republic, asbestos has been classified as a known human carcinogen since 1984. The use of asbestos-containing products was limited to scenarios where the use of other materials was not possible. Since 1997, the manufacture of asbestos materials has been forbidden, and in 1999, the import, manufacture and distribution of all types of asbestos fibres was legally banned by Act No. 157/1998 Coll. Although the use of asbestos is forbidden, the risk of exposure still exists given the ongoing demolition and reconstruction of buildings in which asbestos has been used. In addition, a novel risk has arisen through the quarrying of asbestos-containing aggregates and their subsequent use. The aim of this paper was to describe and evaluate asbestos in terms of history, legislation, current risk of occupational exposure and its health consequences in the Czech Republic over the last three decades. METHODS: This retrospective descriptive study used the collected data on occupational exposure and occupational diseases. The counts of workers occupationally exposed to asbestos were obtained from the Registry of Work Categorization; the numbers and structure of occupational diseases caused by asbestos were taken from the Czech National Registry of Occupational Diseases. Data on the total number of mesothelioma cases recorded in the Czech National Cancer Registry was provided by the Institute of Health Information and Statistics of the Czech Republic. RESULTS: A total of 13,112 subjects were registered as occupationally exposed to asbestos during the period 2001-2020. A total of 687 cases of asbestos-related occupational diseases were reported in the period 1991-2020 in the Czech Republic, comprising 178 cases of asbestosis, 250 cases of pleural hyalinosis, 168 cases of pleural or peritoneal mesothelioma, 90 cases of lung cancer, and one case of laryngeal cancer. The data from the Czech National Cancer Registry, available for a shorter period (1991-2018), reveal 1,389 cases of mesothelioma, of which only ~11% were recognised as occupational, despite the fact that the occupational causality of mesotheliomas is estimated to be up to 90% of mesotheliomas. Moreover, the latency of mesotheliomas since the last occupational exposure reached up to 50 years and this trend is still slightly increasing, unlike asbestosis, where a high cumulative dose of inhaled asbestos is needed. The real proportion of occupational lung cancers may obviously be even higher, especially in smokers, where occupational causes including asbestos are not suspected by most physicians. CONCLUSION: Czech data on asbestos-related occupational diseases, especially cancers, are grossly underestimated, which is most apparent through the low proportion of mesotheliomas diagnosed as occupational. Asbestos materials in older buildings remained in situ and may represent a danger during reconstruction works. The current source of exposure appears to be quarrying of asbestos-containing aggregate and its subsequent use. Awareness of the professional community is therefore crucial, not only for the possibility of compensating those affected, but also for the early detection of the diseases through the dispensary of exposed persons.

Occupational diseases in the automotive industry from medical and geographic viewpoints - comparison between the Czech Republic and the Slovak Republic.

OBJECTIVE: The aim of the study was to compare the occurrence of occupational diseases (ODs) in the automotive industry in the Czech Republic and the Slovak Republic and to analyze their determinants. METHODS: The aggregated and anonymized data on ODs from the period 2001-2017 were used. A questionnaire survey was conducted in the Czech Republic (response rate 70.6%) and in the Slovak Republic (response rate 57%). The occurrence of ODs according to socioeconomic factors, the size of enterprises and their position in the global production networks was evaluated. The quality and scope of the occupational health services were also taken into consideration. RESULTS: Workers older than 40 years were at a significantly higher risk of ODs than the younger ones. In the Czech Republic, it corresponded to OR 2.77 (95% CI 2.41-3.19), in the Slovak Republic to OR 2.01 (95% CI 1.34-3.01). The risk of ODs in women was significantly higher than in men - in the Czech Republic it corresponded to OR 3.20 (95% CI 2.79-3.67), in the Slovak Republic to OR 2.43 (95% CI 2.05-2.87). The difference between the two states did not reach statistical significance in any of the studied factors. In both states, no ODs were reported from the microenterprises. CONCLUSION: Given the results of the study, it can be recommended to focus on the ergonomics of assembly work in the automotive industry. Special attention should be given to the provision of occupational health services, especially in microenterprises.

Role of activation of lipid peroxidation in the mechanisms of acute methanol poisoning.

CONTEXT: The role of activation of lipid peroxidation in the mechanisms of acute methanol poisoning has not been studied. OBJECTIVE: We measured the concentrations of lipid peroxidation markers in acutely intoxicated patients with known serum concentrations of methanol and leukotrienes. METHODS: Blood serum samples were collected from 28 patients hospitalized with acute intoxication and from 36 survivors 2 years after discharge. In these samples, concentrations of 4-hydroxy-trans-2-hexenal (HHE), 4-hydroxynonenal (HNE), and malondialdehyde (MDA) were measured using the method of liquid chromatography-electrospray ionization-tandem mass spectrometry. RESULTS: The maximum acute serum concentrations of all three lipid oxidative damage markers were higher than the follow-up serum concentrations: HNE 71.7 ± 8.0 ng/mL versus 35.4 ± 2.3 ng/mL; p < .001; HHE 40.1 ± 6.7 ng/mL versus 17.7 ± 4.1 ng/mL; p < .001; MDA 80.0 ± 7.2 ng/mL versus 40.9 ± 1.9 ng/mL; p < .001. The survivors without methanol poisoning sequelae demonstrated higher acute serum concentrations of the markers than the patients with sequelae. A correlation between measured markers and serum leukotrienes was present: HNE correlated with LTC4 (r = 0.663), LTD4 (r = 0.608), LTE4 (r = 0.771), LTB4 (r = 0.717), HHE correlated with LTC4 (r = 0.713), LTD4 (r = 0.676), LTE4 (r = 0.819), LTB4 (r = 0.746), MDA correlated with LTC4 (r = 0.785), LTD4 (r = 0.735), LTE4 (r = 0.814), LTB4 (r = 0.674); all p < .001. Lipid peroxidation markers correlated with anion gap (r= -0.428, -0.388, -0.334; p = .026, .045, .080 for HNE, HHE, MDA, respectively). The follow-up serum concentrations of lipid oxidation markers measured in survivors with and without visual/neurological sequelae 2 years after discharge did not differ. CONCLUSION: Our results demonstrate that lipid peroxidation plays a significant role in the mechanisms of acute methanol poisoning. The acute concentrations of three measured biomarkers were elevated in comparison with the follow-up concentrations. Neuronal membrane lipid peroxidation seems to activate leukotriene-mediated inflammation as a part of the neuroprotective mechanisms. No cases of persistent elevation were registered among the survivors 2 years after discharge.

Occupational diseases in the automotive industry in Czechia - Geographic and medical context.

OBJECTIVES: The automotive industry represents the most important industrial sector in Czechia. The objective of this study has been to analyze the occurrence of occupational diseases (OD) in the automotive industry during the period from 2001 till 2014. MATERIAL AND METHODS: Data on OD cases was retrieved from the National Registry of OD. Further, we conducted a survey in automotive companies with focus on occupational health services and positions of the companies in global production networks (GPNs). An analysis of OD distribution in the automotive industry was performed (age, gender, company size and its role in GPNs, regional distribution of studied companies, and regional unemployment rate), and was accompanied by assessment of the quality and range of occupational health services. RESULTS: Employees older than 40 years old have nearly 2.5 times higher probability of OD occurrence as compared with employees younger than 40 years old (odds ratio (OR) = 2.41, 95% confidence interval (CI): 2.05-2.85). Occupational diseases occurrence probability was 3 times higher for women than for men (OR = 3.01, 95% CI: 2.55-3.55). Occupational diseases incidence rates increased with the size of the company (0 OD/10 000 employees in micro enterprises to 57 OD/10 000 employees in large enterprises). A particularly steep rise in OD incidents in the automotive industry was observed in the Plzen Region between 2001 and 2011. An association between OD incidents and the unemployment rate was not statistically confirmed. CONCLUSIONS: A statistically significant increase in OD incidents dependent on company size may be arguably attributed to a higher quality of occupational medical services in bigger companies, which ensures better detection and diagnosis of OD. In the Plzen Region, the rapid increase in OD incidents was mainly caused by a change in the production process of automobile textiles in one factory due to the introduction of a glue containing isocyanates, which are potent allergising agents. This led to an increase in occupational allergic diseases - bronchial asthma in particular. Int J Occup Med Environ Health 2017;30(3):455-468.

Mortality in Miners with Coal-Workers' Pneumoconiosis in the Czech Republic in the Period 1992-2013.

While working underground, miners are exposed to a number of risk factors that have a negative impact on their health and may be a cause of an increased mortality in miners. The aim of the study was to compare total and specific mortality in black coal miners with acknowledged coal-workers' pneumoconiosis (CWP) and without CWP, and the mortality of the general male population in the Czech Republic in the period 1992-2013. The sample consisted of 3476 coal miners with CWP and 6687 ex-coal miners without CWP, who were removed after achieving the maximum permissible exposure (MPE). The mortality risk differences were analyzed with the use of the standardized mortality ratio (SMR) and 95% confidence interval. Significantly higher total mortality (SMR = 1.10; 95% CI: 1.02-1.17), and mortality from malignant neoplasm (SMR = 1.16; 95% CI: 1.03-1.30), lung cancers (SMR = 1.70; 95% CI: 1.41-2.04), and non-malignant respiratory diseases (SMR = 2.78; 95% CI: 2.32-3.31) were found in the sample of coal miners with CWP. In this sample, the severity of CWP was assessed, and the SMR increased with the severity of CWP. The total (SMR = 0.86; 95% CI: 0.82-0.91) and specific mortality of miners without CWP were not higher compared with the general population. In the case where the miners were removed from underground work after achieving the MPE (without CWP), their mortality was not higher than that of the general population, but the mortality of miners with CWP was higher compared to the general population. This mortality was affected by malignant and non-malignant respiratory diseases.

Leukotriene-mediated neuroinflammation, toxic brain damage, and neurodegeneration in acute methanol poisoning.

CONTEXT: The role of neuroinflammation in methanol-induced toxic brain damage has not been studied. OBJECTIVE: We studied acute concentrations and the dynamics of leukotrienes (LT) in serum in hospitalized patients with acute methanol poisoning and in survivors. METHODS: Series of acute cysteinyl-LT and LTB4 concentration measurements were performed in 28/101 hospitalized patients (mean observation time: 88 ± 20 h). In 36 survivors, control LT measurements were performed 2 years after discharge. RESULTS: The acute maximum (Cmax) LT concentrations were higher than concentrations in survivors: Cmax for LTC4 was 80.7 ± 5.6 versus 47.9 ± 4.5 pg/mL; for LTD4, 51.0 ± 6.6 versus 23.1 ± 2.1 pg/mL; for LTE4, 64.2 ± 6.0 versus 26.2 ± 3.9 pg/mL; for LTB4, 59.8 ± 6.2 versus 27.2 ± 1.4 pg/mL (all p < 0.001). The patients who survived had higher LT concentrations than those who died (all p < 0.01). Among survivors, patients with CNS sequelae had lower LTE4 and LTB4 than did those without sequelae (both p < 0.05). The LT concentrations increased at a rate of 0.4-0.5 pg/mL/h and peaked 4-5 days after admission. The patients with better outcomes had higher cys-LTs (all p < 0.01) and LTB4 (p < 0.05). More severely poisoned patients had lower acute LT concentrations than those with minor acidemia. The follow-up LT concentrations in survivors with and without CNS sequelae did not differ (all p > 0.05). The mean decrease in LT concentration was 30.9 ± 9.0 pg/mL for LTC4, 26.3 ± 8.6 pg/mL for LTD4, 37.3 ± 6.4 pg/mL for LTE4, and 32.0 ± 8.8 pg/mL for LTB4. CONCLUSIONS: Our findings suggest that leukotriene-mediated neuroinflammation may play an important role in the mechanisms of toxic brain damage in acute methanol poisoning in humans. Acute elevation of LT concentrations was moderate, transitory, and was not followed by chronic neuroinflammation in survivors.

Evaluation of Lumbar Spine Load by Computational Method in Order to Acknowledge Low-back Disorders as Occupational Diseases.

AIM: The aim of the study was to develop a computational module for the prediction of compressive force on the L4/L5 disc suitable for use in field settings. METHOD: The value of compressive force is intended to be used as a proxy measure of the mechanical burden of low-back when performing work activities. The compressive force predicted by the module in a particular worker should be compared with the NIOSH limit value of 3,400 N for the assessment of lumbar spine load during manual lifting tasks. Exceeding the limit will be considered as the fulfilment of "hygienic criterion" that should be met to acknowledge low-back disorder as an occupational disease. To develop the computational module we used the ergonomic software TECNOMATIX Classic Jack taking into account the anthropometric parameters of a worker and ergonomic parameters of his/her work activity. RESULTS: We calculated compressive forces on the L4/L5 disc in about 1,300 simulated combinations of various factors influencing compressive force. Parameters which turned out to be crucial for the compression of L4/L5 disc were included in the computational algorithm. CONCLUSION: Our study was primarily aimed at the assessment of lumbar disorders as occupational diseases. Moreover, the study can contribute to the recommendation of preventive measures to decrease health risks in occupations associated with the overload of low-back region. The graphic maps generated by the computational module enable a fast and exact analysis of particular job.

LOW-BACK PAIN DISORDERS AS OCCUPATIONAL DISEASES IN THE CZECH REPUBLIC AND 22 EUROPEAN COUNTRIES: COMPARISON OF NATIONAL SYSTEMS, RELATED DIAGNOSES AND EVALUATION CRITERIA.

AIM: Low-back pain diseases (LBPD) belong to the most frequent diagnoses determined by general practitioners, and constitute one of the most common reasons for sick leave and permanent disability pension in the Czech Republic and other European countries. Epidemiological studies have shown a statistically significant association between LBPD and certain types of occupational burden. However, in the Czech Republic, LBPD caused by overload and/or whole-body vibrations have not yet been included in the list of occupational diseases. The aim of this study was to collect and compare the systems, criteria and diagnoses used to recognize LBPD as occupational diseases in other European countries. METHODS: A questionnaire focused on LBPD was distributed and answered by specialists in occupational diseases in European countries. It included items concerning LBPD in the national list of occupational diseases, and work-related and diagnostic criteria that need to be fulfilled for recognizing LBPD as occupational diseases and possible awarding compensations to the patients. RESULTS: In 13 countries out of the 23 countries studied, LBPD caused by overload can be recognized as occupational, providing that the diagnosis is sufficiently proven and exposure criteria and/or listed occupation are met and duration of exposure is confirmed (Belgium, Denmark, France, Germany, Hungary, Italy, Lithuania, Macedonia, Netherlands, Romania, Slovakia, Sweden, and Switzerland). LBPD due to vibrations can be also recognized as occupational in 14 countries. In 8 countries LBPD are not accepted as occupational unless they are caused by an injury at work. Specific criteria to evaluate occupational exposure of patients with LBPD were set in Belgium, Denmark, France, Germany, Lithuania, Macedonia, Netherlands, and Slovakia. In other countries, the evaluation is done at an individual basis. CONCLUSIONS: In practice, the assessment of occupational overload and its contribution to the development of LBPD as well as its inclusion in the compensation system are important for several reasons. Firstly, it may be considered essentially preventable. Secondly, cases with a significant contribution of occupational aetiology may be viewed as occupational diseases for which compensation may be claimed, as it is the case in many European countries. Importantly, inclusion of LBPD in the list of occupational diseases or another system of compensation may be viewed as a preventive measure as it increases the visibility of this problem not only for the workers, but especially for the employers.

Successful Use of Hydroxocobalamin and Sodium Thiosulfate in Acute Cyanide Poisoning: A Case Report with Follow-up.

Hydroxocobalamin is an effective first-line antidote used mainly in monotherapy of cyanide poisonings, while the opinions are different on the effects of its combination with sodium thiosulfate. A 58-year-old male committed a suicide attempt by ingesting of 1200-1500 mg of potassium cyanide; he was unconscious for 1-1.5 min. after ingestion with the episode of generalized seizures. On admission to the ICU, the patient was acidotic (pH 7.28; HCO3 14.0 mmol/L, base excess -12.7 mmol/L, saturation O2 0.999) with high serum lactate (12.5 mmol/L). Hydroxocobalamin was administered 1.5 hr after ingestion in two subsequent intravenous infusions at a total dose of 7.5 g. The infusion was followed by continuous intravenous administration of 1 mL/hr/kg of 10% sodium thiosulfate at a total dose of 12 g. No complications and adverse reactions were registered. Serum lactate decreased to 0.6 mmol/L the same day, and arterial blood gases became normal (pH 7.49; HCO3 27.2 mmol/L, base excess 2.2 mmol/L, saturation O2 0.994). The follow-up examination 5 months later revealed no damage of basal ganglia and cerebellum on magnetic resonance imaging. The neurological examination revealed no pathological findings. On the ocular coherence tomography, the retinal nerve fibres layer was normal. In visual evoked potentials, there was a normal evoked complex on the left eye and minor decrease in amplitude on the right eye. Combination of hydroxocobalamin and sodium thiosulfate can have a positive effect on the survival without long-term neurological and visual sequelae in the cases of massive cyanide poisonings due to the possibility of a potentiation or synergism of hydroxocobalamin effects by sodium thiosulfate. This synergism can be explained by the different time-points of action of two antidotes: the initial and immediate effect of hydroxocobalamin, followed by the delayed, but more persistent effect of sodium thiosulfate.

Twenty year development of occupational diseases in the Czech Republic: medical and geographical aspects.

The study analysed occupational diseases in the Czech Republic from the viewpoint of occupational medicine and medical geography. It used a dataset consisting of 32,646 cases of occupational diseases reported during the period of 1994-2013. The descriptive part of the study analysed occupational diseases according to their spatial distribution, occurrence in different branches of economic activities, employees' gender, and according to chapters of the List of occupational diseases. The incidence of occupational diseases showed an overall decreasing trend, which can be related to several factors--transformation of the national economy (shift from heavy industry to manufacturing industry and services), an improvement in access to occupational healthcare services, increased responsibility of employers for safe working conditions, but also a concealment of health problems by employees for fear of losing job. An exception to the decreasing trend is the automotive industry, in which the upward trend in occupational diseases occurrence was noted. The analytical part of the study focused on the relation between unemployment and occupational diseases incidence rates in different regions of the Czech Republic. In most regions, a statistically significant inverse association was shown between the rate of unemployment and occupational disease incidence. The situation is described in more detail for the Moravia-Silesia and Ustí nad Labem Regions and the Capital City of Prague, wherein a statistically significant inverse association was shown between the rate of unemployment and occupational disease incidence. The theory of marginal utility can explain the phenomenon. To certain degree of health problems, employees tend to prefer employment stability, especially if the unemployment is on rise in their region. On the other hand, if losing their job, they often try to claim benefits connected with occupational diseases.

Cancer incidence in Czech black coal miners in association with coalworkers' pneumoconiosis.

OBJECTIVE: The aim of the study was comparison of cancer incidence risk of lungs, stomach, colon, bladder and kidneys from ex-miners of black coal mines and the general male population of the Czech Republic. MATERIALS AND METHODS: The analysis was conducted in two cohorts of ex-miners according to the presence of coalworkers' pneumoconiosis (CWP). The first cohort included the miners without CWP (N = 6705), and the second cohort included the miners who were compensated for CWP (N = 2158). Personal and occupational data was merged with the data in the National Population Register and the National Oncological Register for the period from 1992 to 2006. Cancer risk in miners in comparison to the general male population of the Czech Republic was evaluated by SIR (Standardized Incidence Ratio) and 95% confidence interval (CI). RESULTS: About twice as high risk of lung cancer was found in miners with CWP (SIR = 2.21; 95% CI: 1.75-2.76). Lung cancer risk correlated with the severity of CWP (simple CWP SIR=1.96; 95% CI: 1.48-2.56, progressive massive fibrosis SIR = 4.29; 95% CI: 2.09-7.87). No increased risk of lung cancer was found in ex-miners without CWP. The risk of malignant neoplasm at the other selected sites was comparable with the risk in the general male population of the Czech Republic. CONCLUSIONS: This study found increased lung cancer risk in coal miners with CWP, but not in those without CWP, comparing with the general population. These results served as the basis for the inclusion of lung cancer in association with CWP into a new Czech list of occupational diseases.

Increased oxidative/nitrosative stress markers measured non- invasively in patients with high 2,3,7,8-tetrachloro-dibenzo-p-dioxin plasma level.

OBJECTIVES: 2,3,7,8-tetrachloro-dibenzo-p-dioxin (TCDD) is a highly toxic persistent environmental contaminant, classified as a human carcinogen affecting any target organ. The mechanism of carcinogenesis by TCDD is unclear as TCDD shows a lack of direct genotoxicity. Experimental studies also support the role of oxidative stress in TCDD neurotoxicity and vascular dysfunction. The aim was to investigate markers of oxidative/nitrosative stress and inflammation using non-invasive methods in subjects who got ill due to severe occupational exposure to TCDD in the years 1965-1968. METHODS: In 11 TCDD-exposed patients, and 16 controls, the analysis of following oxidative products of lipids, proteins and nucleic acids in plasma, urine and exhaled breath condensate (EBC) was performed: 8-iso-prostaglandin F2α (8-isoprostane), 4-hydroxy-trans-2-nonenale (HNE), malondialdehyde (MDA), o-tyrosine (o-Tyr), 8-hydroxyguanosine (8-OHG), 8-hydroxy-2´-deoxy-guanosine (8-OHdG), 5-hydroxymethyluracil (5-OHMeU). In addition, nitric-oxide-tyrosine (NO-Tyr) and leukotriene (LT) B4, C4, D4, and E4 were detected by liquid chromatography-mass spectrometry/mass spectrometry (LC-ESI-MS/MS). TCDD was measured by HRGC/HRMS, body lipid content by densitometry. Single-photon emission spectrometry (SPECT) of the brain was performed and compared with the findings of the patients in 2008. RESULTS: Mean TCDD plasma level in 2010 was 175 ± 162 pg/g lipids (population level about 2 pg/g), total TCDD content in the body 5.16 ± 4.62 mg. Reduction of cerebral blood flow in SPECT progressed in 8 patients, finding was stable in 2 subjects, and improvement occurred in 1 patient. In the EBC, 10 from 12 markers (all except LT D4 and LT E4), were significantly increased in the patients (p<0.05). In the urine, 7 markers were significantly higher than in the controls (p<0.05): 8-isoprostane, MDA, HNE, LT C4, LT E4, o-Tyr and NO-Tyr. In plasma, only NO-Tyr and 8-OHG were elevated (p<0.05). CONCLUSION: NO-Tyr was increased in all matrices in dioxin-exposed patients. EBC is not limited to lung disorders as the markers of oxidative stress and inflammation were elevated in EBC of patients with normal lung functions. TCDD-induced oxidative stress and inflammation markers can be detected non-invasively in the EBC and urine in the follow-up of the highly-exposed patients. Their prognostic value, however, needs to be elucidated.

Higher aluminum concentration in Alzheimer's disease after Box-Cox data transformation.

Evidence regarding the role of mercury and aluminum in the pathogenesis of Alzheimer's disease (AD) remains controversial. The aims of our project were to investigate the content of the selected metals in brain tissue samples and the use of a specific mathematical transform to eliminate the disadvantage of a strong positive skew in the original data distribution. In this study, we used atomic absorption spectrophotometry to determine mercury and aluminum concentrations in the hippocampus and associative visual cortex of 29 neuropathologically confirmed AD and 27 age-matched controls. The Box-Cox data transformation was used for statistical evaluation. AD brains had higher mean aluminum concentrations in the hippocampus than controls (0.357 vs. 0.090 µg/g; P = 0.039) after data transformation. Results for mercury were not significant. Original data regarding microelement concentrations are heavily skewed and do not pass the normality test in general. A Box-Cox transformation can eliminate this disadvantage and allow parametric testing.

Occupational hypersensitivity pneumonitis reported to the Czech National Registry Of Occupational Diseases in the period 1992-2005.

Between 1992 and 2005, 72 cases of occupational hypersensitive pneumonitis were reported to the Czech National Registry of Occupational Diseases. This represented 0.24% of all occupational diseases reported in the Czech Republic during that period. The greatest number of cases occurred in 1997 (10 cases), of which men constituted 58.3% (42 cases) and women 41.7% (30 cases). The most prevalent cases were farmer's lung (50 cases), malt worker's lung (7 cases) and chemical worker's lung (6 cases). Agriculture was the most common economic activity (total 48 cases), with cattleman and dairyman (total 26 cases) the most frequent occupations; less common were tractor driver (8 cases) and maltster (7 cases). Typical case reports after different exposures are presented. A peak in frequency was observed in the age groups of 45-49 and 50-54 yr (20.8% and 19.4% of cases, respectively) and within the first four years of employment (22.2% of cases). Median age was 48 yr and median exposure 12.5 yr. Incidence was in the range of 0.00-0.20 per 100,000 workers, which appears rather low. Due to the difficult diagnostics of hypersensitive pneumonitis, the actual number of cases is undoubtedly higher, and this disease is probably under-reported.

Asbestos exposure, legislation and diseases in the Czech Republic.

Asbestos manufacturing has been banned in the Czech Republic; however, about 280 workers in the 2nd-4th work category have been exposed during the remediation of asbestos, and the health consequences of the former use of asbestos will be apparent for many years. The incidence of mesothelioma in the Czech Republic is about 0.5/100,000 inhabitants, which places it among the lowest incidences of mesothelioma in Europe, and ranks the Czech Republic among the countries with the lowest rates in the world. The proportion of occupational mesotheliomas is only about one-tenth of these malignancies. These data show an underreporting of occupational cancers, most probably due to low awareness of the association of exposures more than 40 years ago with this disease. Physicians should focus more on the occupational history of these patients and refer them to the Departments of occupational diseases. Benefits are available for all patients with mesothelioma, in whom industrial hygienists confirm former exposure to asbestos, corresponding to the latency period.

Color discrimination impairment in workers exposed to mercury vapor.

OBJECTIVE: To study color discrimination impairment in workers exposed to elemental mercury (Hg) vapor. SUBJECTS: Twenty-four male workers from a chloralkali plant exposed to Hg vapor, aged 42+/-9.8 years, duration of exposure 14.7+/-9.7 years, were examined. The 8h TWA air-borne Hg concentration in workplace was 59 microg/m(3); mean Hg urinary excretion (HgU) was 20.5+/-19.3 microg/g creatinine; mean Hg urinary excretion after the administration of a chelating agent, sodium 2,3-dimercapto-1-propane-sulfonate (DMPS), was 751.9+/-648 microg/48h. Twenty-four age- and gender-matched control subjects were compared. Visual acuity, alcohol intake, smoking habits, and history of diseases or drugs potentially influencing color vision were registered. METHODS: The Lanthony 15-Hue desaturated test (L-D15-d) was used to assess color vision. The results were expressed quantitatively as Bowman's Color Confusion Index (CCI), and qualitatively according to Verriest's classification of acquired dyschromatopsias. RESULTS: The CCI was significantly higher in the exposed group than in the control (mean CCI 1.15 versus 1.04; P=0.04). The proportion of subjects with errorless performance on the Lanthony test was significantly lower in the Hg exposed group compared to referents (52% versus 73%; P=0.035). The exposed group showed higher frequency of type III dyschromatopsias (blue-yellow confusion axis) in comparison with the control group (12.5% versus 8.3%), however, the difference did not reach statistical significance. Multiple regression did not show any significant relationship between the CCI, and age, alcohol consumption, or measures of exposure. CONCLUSION: In agreement with previous studies by Cavalleri et al. [Toxicol. Lett. 77 (1995) 351; Environ. Res. Sec. A 77 (1998) 173], the results of this study support the hypothesis that exposure to mercury vapor can induce sub-clinical color vision impairment. This effect was observed at an exposure level below the current biological limit for occupational exposure to mercury. This raises doubts on the actual protection afforded by this limit concerning the effect of mercury on color vision.