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.

Exposure criteria for evaluating lumbar spine load.

OBJECTIVE: As a part of regular revision of the List of Occupational Diseases in the Czech Republic, efforts have been made to add a new item so that lumbar spine disease caused by overload may be recognized as occupational one, with adherence to the valid national rules, that is, clinical criteria are met and objective assessment confirms working conditions under which, according to recent scientific knowledge, such an occupational disease develops. The aim is to provide information on the use of a proposed method for working condition assessment in a real setting, based on the initial experiences gained from a pilot study carried out to validate the method. METHODS: Working conditions were assessed in 55 individuals with chronic low back pain (25 males, 30 females; mean age 45.6 years; mean length of employment 15.6 years). The assessment was based on estimating compressive force on the L4/L5 intervertebral disc when performing potentially high-risk work tasks which were entered into four types of checklists throughout their work shifts. The compression values were calculated using a special module that was developed. RESULTS: In 24 cases comprehensive assessment of all tasks performed showed fulfillment of the proposed criteria of working conditions needed for recognition of occupational disease. Those included healthcare, foundry and forest workers, production operators, cabinetmakers, locksmiths, bricklayers, etc. In all the cases, lumbar spine overload was associated with work tasks requiring combinations of manual handling of objects and trunk rotation or bending. The criteria were not met in 31 subjects. The mean length of employment was 15.4 and 15.8 years in patients who met and did not meet the proposed criteria, respectively. CONCLUSION: The proposed method proved to be applicable in occupational hygiene evaluation in a real setting.

Use of Out-of-Hospital Ethanol Administration to Improve Outcome in Mass Methanol Outbreaks.

STUDY OBJECTIVE: Methanol poisoning outbreaks are a global public health issue, with delayed treatment causing poor outcomes. Out-of-hospital ethanol administration may improve outcome, but the difficulty of conducting research in outbreaks has meant that its effects have never been assessed. We study the effect of out-of-hospital ethanol in patients treated during a methanol outbreak in the Czech Republic between 2012 and 2014. METHODS: This was an observational case-series study of 100 hospitalized patients with confirmed methanol poisoning. Out-of-hospital ethanol as a "first aid antidote" was administered by paramedic or medical staff before the confirmation of diagnosis to 30 patients; 70 patients did not receive out-of-hospital ethanol from the staff (12 patients self-administered ethanol shortly before presentation). RESULTS: The state of consciousness at first contact with paramedic or medical staff, delay to admission, and serum methanol concentration were similar among groups. The median serum ethanol level on admission in the patients with out-of-hospital administration by paramedic or medical staff was 84.3 mg/dL (interquartile range 32.7 to 129.5 mg/dL). No patients with positive serum ethanol level on admission died compared with 21 with negative serum ethanol level (0% versus 36.2%). Patients receiving out-of-hospital ethanol survived without visual and central nervous system sequelae more often than those not receiving it (90.5% versus 19.0%). A positive association was present between out-of-hospital ethanol administration by paramedic or medical staff, serum ethanol concentration on admission, and both total survival and survival without sequelae of poisoning. CONCLUSION: We found a positive association between out-of-hospital ethanol administration and improved clinical outcome. During mass methanol outbreaks, conscious adults with suspected poisoning should be considered for administration of out-of-hospital ethanol to reduce morbidity and mortality.

Anomalous heat transport and condensation in convection of cryogenic helium.

When a hot body A is thermally connected to a cold body B, the textbook knowledge is that heat flows from A to B. Here, we describe the opposite case in which heat flows from a colder but constantly heated body B to a hotter but constantly cooled body A through a two-phase liquid-vapor system. Specifically, we provide experimental evidence that heat flows through liquid and vapor phases of cryogenic helium from the constantly heated, but cooler, bottom plate of a Rayleigh-Bénard convection cell to its hotter, but constantly cooled, top plate. The bottom plate is heated uniformly, and the top plate is cooled by heat exchange with liquid helium maintained at 4.2 K. Additionally, for certain experimental conditions, a rain of helium droplets is detected by small sensors placed in the cell at about one-half of its height.

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.

Trends in incidence of occupational asthma, contact dermatitis, noise-induced hearing loss, carpal tunnel syndrome and upper limb musculoskeletal disorders in European countries from 2000 to 2012.

OBJECTIVES: The European Union (EU) strategy for health and safety at work underlines the need to reduce the incidence of occupational diseases (OD), but European statistics to evaluate this common goal are scarce. We aim to estimate and compare changes in incidence over time for occupational asthma, contact dermatitis, noise-induced hearing loss (NIHL), carpal tunnel syndrome (CTS) and upper limb musculoskeletal disorders across 10 European countries. METHODS: OD surveillance systems that potentially reflected nationally representative trends in incidence within Belgium, the Czech Republic, Finland, France, Italy, the Netherlands, Norway, Spain, Switzerland and the UK provided data. Case counts were analysed using a negative binomial regression model with year as the main covariate. Many systems collected data from networks of 'centres', requiring the use of a multilevel negative binomial model. Some models made allowance for changes in compensation or reporting rules. RESULTS: Reports of contact dermatitis and asthma, conditions with shorter time between exposure to causal substances and OD, were consistently declining with only a few exceptions. For OD with physical causal exposures there was more variation between countries. Reported NIHL was increasing in Belgium, Spain, Switzerland and the Netherlands and decreasing elsewhere. Trends in CTS and upper limb musculoskeletal disorders varied widely within and between countries. CONCLUSIONS: This is the first direct comparison of trends in OD within Europe and is consistent with a positive impact of European initiatives addressing exposures relevant to asthma and contact dermatitis. Taking a more flexible approach allowed comparisons of surveillance data between and within countries without harmonisation of data collection methods.

Imaging findings after methanol intoxication (cohort of 46 patients).

OBJECTIVES: Our goal is to demonstrate the variability of imaging findings, primarily in the MRI, in 46 patients who survived acute methanol poisoning. This cohort of patients is the largest such sample group examined by MRI. METHODS: Patients were examined by means of imaging methods (42 patients by MRI and 4 by CT). All had an identical protocol of MR examination (T2WI, FLAIR, T1WI with or without application of contrast medium and T2WI/FFE, DWI in the transversal plane of the scan, and with focus on the optic nerves in the coronal plane of the scan in T2WI-SPIR). RESULTS: Imaging methods revealed a positive finding associated with methanol intoxication in 21 patients (46%). These consisted of symmetrical lesions in the putamen--13 patients (28%), haemorrhage--13 cases (28%), deposits in white matter with localization primarily subcortically--4 cases (9%), lesions in the region of the globus pallidus--7 cases (15%) (in 6 cases without combination with the lesions in the putamen), lesions in the brainstem afflicted 6 patients (13%), and lesion in the cerebellum was found in one case. A pathological finding was found only in the patients examined by MRI. CONCLUSION: Almost half of the patients who survived acute methanol poisoning had pathological findings by MRI. The most common finding concerned an affliction of the putamen, which is a predilection area. An interesting finding was the relatively frequent occurrence of selective lesion of the globus pallidus, which is more usually associated with other types of intoxication.

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.

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.

Occupational viral hepatitis in the Slovak and the Czech Republic.

BACKGROUND: The proportion of occupational infectious diseases (ID) in the total number of occupational diseases reported in the Slovak Republic (SR) and the Czech Republic (CR) was decreasing from 1973 to 2010. Our study presents a longitudinal analysis of the occurrence of occupational infectious diseases in the Slovak Republic and the Czech Republic in the period from 1973-2010 with special focus on viral hepatitis. METHODS: The sources of data were national health statistics of Czechoslovakia, the Czech Republic and the Slovak Republic. Descriptive statistical methods were used for data analysis. Incidence rate of reported diseases was calculated per 100,000 general population or per 100,000 people insured. RESULTS: During the studied period, a total of 2,931 and 8,318 cases of occupational viral hepatitis (VH) were reported in the Slovak Republic and the Czech Republic, respectively. The incidence culminated in the late 1970s when hepatitis represented almost 50% of all reported occupational infectious diseases. Most cases of occupational hepatitis occurred in health and social services. Since the early 1980s, a steep decrease in the incidence of hepatitis has been observed due to the gradual implementation of mandatory vaccination against hepatitis A and B in risk groups. In SR in 1973, the incidence rate of occupational infectious diseases and that of occupational viral hepatitis was 10.85/100,000 and 1.86/100,000, respectively. In 2010, these rates decreased to 0.74/100,000 and 0.20/100,000, respectively. In CR, the incidence rates of occupational infectious diseases and that of occupational viral hepatitis reported in 1973 were 11.75/100,000 and 3.69/100,000. In 2010, reported incidence rates were 1.71/100,000 and 0.10/100,000, respectively. CONCLUSION: Although the incidence of occupational viral hepatitis has dramatically decreased in the Slovak and the Czech Republic as well as in other Visegrad group countries during the studied period, we emphasize the necessity of continuing epidemiological surveillance of hepatitis, especially with regard to the recent incidence increase of viral hepatitis C.

Höffding step and beyond: The impact of visual sensory impairment on cognitive performance in neuropsychological testing of survivors of acute methanol poisoning.

BACKGROUND: Sensory deficits can result in limitations regarding how well neuropsychological test findings can be interpreted. Only a few studies have investigated the influence of vision alteration on neuropsychological tests. In 2012 the Czech Republic experienced mass methanol poisoning. Methanol metabolites cause histotoxic hypoxia to the optic nerve. OBJECTIVE: In the current study, the effect of the toxic damage on the parts of the visual pathway on visual and non-visual neuropsychological measures was investigated using electrophysiological methods (visual evoked potential (VEP) and optical coherence tomography (OCT) with retinal nerve fibre layer (RNFL) thickness measurement. METHODS: 53 individuals who experienced methanol poisoning participated in this research (76% men; ages 24 to 74 years, mean = 43.8±14.6 years; education 11.9±1.4 years). Each participant underwent comprehensive neurological, ophthalmological, and neuropsychological examinations. RESULTS: The results of mixed-effect models revealed significant small to a medium association between the Stroop test weak interference and Grooved Pegboard with the left eye global, nasal and temporal RNFL thickness. Also, medium associations between the Finger Tapping test and the Stroop test weak interference and left eye temporal RNFL, right eye temporal RNFL, and the latency P1 of VEP in the left eye were significant. CONCLUSION: The results of this study found a small to medium association (r = .15- .33; p = .010- .046) between RNFL thickness and cognitive visual test performance. Careful interpretation is suggested regarding results obtained from visual tests of the executive or motor functioning with participants with RNFL decrease or other types of early visual processing damage.

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.

MRI-based brain volumetry and retinal optical coherence tomography as the biomarkers of outcome in acute methanol poisoning.

BACKGROUND: Basal ganglia lesions are typical findings on magnetic resonance imaging (MRI) of the brain in survivors of acute methanol poisoning. However, no data are available on the association between the magnitude of damaged brain regions, serum concentrations of markers of acute methanol toxicity, oxidative stress, neuroinflammation, and the rate of retinal nerve ganglion cell loss. OBJECTIVES: To investigate the association between MRI-based volumetry of the basal ganglia, retinal nerve fibre layer (RNFL) thickness and prognostic laboratory markers of outcomes in acute methanol poisoning. METHODS: MRI-based volumetry of putamen, nucleus caudatus and globus pallidus was performed and compared with laboratory parameters of severity of poisoning and acute serum markers of oxidative damage of lipids (8-isoprostan, MDA, HHE, HNE), nucleic acids (8-OHdG, 8-OHG, 5-OHMU), proteins (o-Thyr, NO-Thyr, Cl-Thyr) and leukotrienes (LTC4, LTD4, LTE4, LTB4), as well as with the results of RNFL measurements by optic coherence tomography (OCT) in 16 patients with acute methanol poisoning (Group I) and in 28 survivors of poisoning two years after discharge with the same markers measured within the follow-up examination (Group II). The control group consisted of 28 healthy subjects without methanol poisoning. RESULTS: The survivors of acute methanol poisoning had significantly lower volumes of basal ganglia than the controls. The patients with MRI signs of methanol-induced toxic brain damage had significantly lower volumes of basal ganglia than those without these signs. A positive correlation was found between the volume of putamen and arterial blood pH on admission (r = 0.45; p = 0.02 and r = 0.44; p = 0.02 for left and right putamen, correspondingly). A negative correlation was present between the volumes of putamen and acute serum lactate (r = -0.63; p < 0.001 and r = -0.59; p = 0.01), creatinine (r = -0.53; p = 0.01 and r = -0.47; p = 0.01) and glucose (r = -0.55; p < 0.001 and r = -0.50; p = 0.01) concentrations. The volume of basal ganglia positively correlated with acute concentrations of markers of lipoperoxidation (8-isoprostan: r = 0.61; p < 0.05 and r = 0.59; p < 0.05 for left and right putamen, correspondingly) and inflammation (leukotriene LTB4: r = 0.61; p < 0.05 and r = 0.61; p < 0.05 for left and right putamen, correspondingly). The higher the volume of the basal ganglia, the higher the thickness of the RNFL, with the strongest positive association between global RNFL and the volume of putamen bilaterally (all p < 0.01). In the follow-up markers of oxidative stress and inflammation, only o-Thyr concentration negatively correlated with the volume of putamen bilaterally (r = -0.39; p < 0.05 and r = -0.37; p < 0.05 for left and right putamen, correspondingly). CONCLUSION: In survivors of acute methanol poisoning with signs of toxic brain damage, the magnitude of affected areas correlated with acute parameters of severity of poisoning, markers of oxidative stress and neuroinflammation. There was a positive association between the basal ganglia volume and the thickness of RNFL, making OCT an important screening test and MRI-based volumetry the confirmative diagnostic method for the detection of CNS sequelae of methanol poisoning.

Health-related quality of life determinants in survivors of a mass methanol poisoning outbreak: six-year prospective cohort study.

Purpose: The effect of acute methanol poisoning on the follow-up quality of life of survivors in mass poisoning outbreaks is not known. The objective of this is to study the impact of visual and central nervous system (CNS) sequelae of methanol poisoning on long-term health-related quality of life (QoL) of survivors, its clinical determinants, and dynamics.Materials and methods: A total of 54 patients with confirmed methanol poisoning (mean age 46.7 ± 13.4 years, 9 females) were examined consequently three times within six-year prospective cohort study and compared to 23 controls with the history of chronic alcohol abuse. The following tests were performed: SF-36 QoL questionnaire, visual evoked potentials (VEP) of optic nerve, ocular examination with retinal nerve fiber layer (RNFL) thickness measurement, brain magnetic resonance imaging (MRI), and biochemical and toxicological tests.Results: Acute methanol poisoning led to significant decrease in physical component summary (PCS) compared to PCS of age-adjusted controls (mean score with SD 46.8 ± 11.0 versus 52.3 ± 9.4 points; p = .003). In 17/40 (42.5%) patients with three rounds of examination, signs of severe disability (≤30 points in at least one score) were present six years after discharge, with negative dynamics of PCS score during the observation period. The patients with abnormal RNFL thickness had lower PCS (mean difference 10.5 points; 95%CI 3.5-17.5, p = .004) and mental component summary score (9.5 points; 95%CI 1.9-17.1, p = .015) compared to the patients with normal RNFL. Signs of physical and mental adaptation to long-term visual sequelae were registered with gradual reduction of difference in most of physical and mental components scores compared to the patients with normal RNFL during six years of observation. Signs of hemorrhagic brain lesions were associated with permanent decrease of PCS score (mean difference 7.4 points; 95%CI 0.6-14.0; p = .033), bodily pain (8.7 points; 95%CI 1.6-17.6; p = .018), and social functioning (8.2 points; 95%CI 3.0-17.4; p = .005) six years after discharge. No effect of type of antidote (fomepizole versus ethanol) and extracorporeal enhanced elimination modality (intermittent hemodialysis versus continuous renal replacement therapy) applied in hospital on long-term QoL was found (all p > .05).Conclusion: Acute methanol poisoning was associated with a significant decrease of health-related quality of life of survivors persisting for at least six years after discharge. The more pronounced decrease in QoL scores was observed in the patients with hemorrhagic brain lesions and visual sequelae of poisoning with abnormal RNFL thickness.

Chronic health impairment due to 2,3,7,8-tetrachloro-dibenzo-p-dioxin exposure.

OBJECTIVES: The aim of this study, performed in 2008, was to evaluate the consequences of severe occupational intoxication with 2,3,7,8-tetrachloro-dibenzo-p-dioxin (TCDD) that occurred during production of the herbicide trichlorophenoxyacetic acid in the period 1965-1968. DESIGN: Examination of 11 men, mean age 64.4+/-1.5 years, included: internal and neurological examination, eye fundus examination, TCDD in plasma, thyroid-stimulating hormone (TSH), testosterone and serum lipids, ultrasonography of the carotid artery, nerve conduction study (NCS), electroencephalography (EEG), visual evoked potential (VEP), Lanthony test of acquired visual impairment, single photon emission computer tomography (SPECT) of the brain, neuropsychological examination and carbohydrate-deficient transferrin (CDT), a marker of chronic ethanol intake. RESULTS: Mean TCDD level in 2008 was still 274.0+/-181.2 pg/g blood lipids (reference level is 2-3 pg/g). All (100%) patients had residues of chloracne/chloracne consequences, atherosclerotic changes on the eye fundus and plaques in the carotid arteries. Progression of intima-media thickness (IMT) from a mean of 0.84+/-0.14 mm in 2003 to 1.09+/-0.18 mm in 2008 was observed. Ninety-one per cents of patients had impairment in SPECT of the brain; and 55% of patients had hyperfixation of the perfusion indicator as a measure of increased neuronal activity. Additionally, 91 % of patients were treated for hyperlipidaemia, 73 % for hypertension, 55 % for diabetes type 2, 45 % for ischemic heart disease, and 36 % for psychological disorders. The Lanthony test demonstrated acquired dyschromatopsia in 80 % of patients. Mean colour confusion index (CCI) was 1.438, which indicates impairment since 2003, when the index was 1.302. CDT was in the normal range and did not correlate with CCI. Neuropsychological status appeared stabilized in all 8 patients examined, with impairment in one or more parameter (memory, attention, verbal fluency, psychomotor speed, motorics) in comparison to the norm. CONCLUSION: Forty years after intoxication, the blood level of TCDD is still 100 times higher than in the general population. Other PCDD/Fs were not elevated. A high percentage of subjects suffer from neurological and vascular disorders. No association of alcohol consumption with neurological impairment was seen, and the highly significant correlation between CCI and TCDD blood concentration suggests that acquired colour impairment was associated with TCDD but not with alcohol consumption. IMT significantly increased during past 5 years. The patients obviously need complex treatment, including intense hypolipidaemic and antidepressant therapy.

Clinical and genetic determinants of chronic visual pathway changes after methanol - induced optic neuropathy: four-year follow-up study.

CONTEXT: Methanol poisoning induces acute optic neuropathy with possible long-term visual damage. OBJECTIVE: To study the dynamics and key determinants of visual pathway functional changes during 4 years after acute methanol poisoning. METHODS: A total of 42 patients with confirmed methanol poisoning (mean age 45.7 ± 4.4 years) were examined 4.9 ± 0.6, 25.0 ± 0.6, and 49.9 ± 0.5 months after discharge. The following tests were performed: visual evoked potential (VEP), retinal nerve fiber layer (RNFL) measurement, brain magnetic resonance imaging (MRI), complete ocular examination, biochemical tests, and apolipoprotein E (ApoE) genotyping. RESULTS: Abnormal VEP P1 latency was registered in 18/42 right eyes (OD) and 21/42 left eyes (OS), abnormal N1P1 amplitude in 10/42 OD and OS. Mean P1 latency shortening during the follow-up was 15.0 ± 2.0 ms for 36/42 (86%) OD and 14.9 ± 2.4 ms for 35/42 (83%) OS, with maximum shortening up to 35.0 ms. No significant change of mean N1P1 amplitude was registered during follow-up. A further decrease in N1P1 amplitude ≥1.0 mcV in at least one eye was observed in 17 of 36 patients (47%) with measurable amplitude (mean decrease -1.11 ± 0.83 (OD)/-2.37 ± 0.66 (OS) mcV versus -0.06 ± 0.56 (OD)/-0.83 ± 0.64 (OS) mcV in the study population; both p < .001). ApoE4 allele carriers had lower global and temporal RNFL thickness and longer initial P1 latency compared to the non-carriers (all p < .05). The odds ratio for abnormal visual function was 8.92 (3.00-36.50; 95%CI) for ApoE4 allele carriers (p < .001). The presence of ApoE4 allele was further associated with brain necrotic lesions (r = 0.384; p = .013) and brain hemorrhages (r = 0.395; p = .011). CONCLUSIONS: Improvement of optic nerve conductivity occurred in more than 80% of patients, but evoked potential amplitude tended to decrease during the 4 years of observation. ApoE4 allele carriers demonstrated lower RNFL thickness, longer P1 latency, and more frequent methanol-induced brain damage compared to non-carriers.

A response to the Comment on Tomaskova et al. Mortality in Miners with Coal-Workers' Pneumoconiosis in the Czech Republic in the Period 1992-2013. Int. J. Environ. Res. Public Health, 2017, 14, 269 by the Author Mei Yong.

At first, we would like to thank Mei Yong for the comments on our article Mortality in Miners with Coal-Workers' Pneumoconiosis in the Czech Republic in the Period 1992-2013 [...].

Neurological and Neurophysiological Findings in Workers with Chronic 2,3,7,8-Tetrachlorodibenzo-p-Dioxin Intoxication 50 Years After Exposure.

The last eight survivors of 80 workers accidentally exposed to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) during production of herbicides based on trichlorophenoxyacetic acid in 1965-1967 in a chemical factory were followed. All were men, mean age 72.4 ± 1.3 years. Their current median TCDD blood level was 112 (46-390) pg/g lipids. Neurological examination revealed central nervous system impairment in all individuals and signs of polyneuropathy in 87.5%, which was confirmed by a nerve conduction study (NCS) in 75%. A Lanthony test demonstrated acquired dyschromatopsia in 87.5% of the patients, with deterioration of mean colour confusion index (CCI) from 1.52 ± 0.39 in 2010 to 1.73 ± 0.41 in 2016. Single-photon emission computer tomography (SPECT) of the brain showed focal reduction of perfusion in various brain locations in all patients and worsening in six patients. Visual-evoked potentials (VEP) was abnormal in 62.6% of individuals. Most patients complained of psychological problems. The neuropsychological test battery showed most positive impairments in the Trail Making Test evaluating processing speed (average level in the range of mild neurocognitive impairment), which correlated with mean CCI (p < 0.05). CONCLUSION: Fifty years after exposure, blood levels of TCDD are still 10 times higher than the general population. NCS, VEP, Lanthony test and SPECT findings deteriorated from examination of these patients in 2004 and in 2010. The total of abnormal tests per patient in 2016 is very high. Minor differences among patients and their reduced count may explain why the number of impairments in 2016 does not correlate with TCDD blood level.