Prognostic significance of low serum levels of Clara cell phospholipid-binding protein in occupational aluminium neurotoxicity.

The relationship between respiratory and neurological effects of exposure to aluminium (Al) was investigated in a group of foundry workers exposed to Al at concentrations below the threshold limit value (TLV) binding in Poland (2.0 mg Al2O3 m(-3)). Neurological and neurophysiological parameters indicated subclinical effects of Al exposure on the nervous system. The measurement of serum anti-inflammatory Clara cell protein (CC16) was employed as a peripheral marker of the lung epithelium function. There was a strong inverse relationship between serum Al (Al-S) and CC16 concentrations (p = 0.006). The lowest CC16 concentrations were found in serum of workers characterised by subjective symptoms of the central nervous system (CNS) and abnormal results of neurophysiological examinations (EEG and VEP). Low serum CC16 concentrations and enhanced Al and iron (Fe) levels were also observed in the younger age group of workers with the subjective CNS symptoms and abnormal VEP results, which suggests that Fe is implicated in strengthening of the neurotoxic Al potential. The results of our study support the hypothesis that subclinical neurological symptoms (especially abnormal VEP) are most likely associated with internalisation of Al ions with lipid fractions of the lung epithelium, which in turn may help Al ions overcome the blood-brain barrier. Low serum CC16 concentrations (<10 microg L(-1)) were noted in workers with the abnormal results of neurological (CNS) and neurophysiological (EEG and VEP) examinations as well as with Al body burden manifested by urinary excretion (Al-U) below 60 microg L(-1) and Al-S concentration of 2 microg L(-1). This concentration may be considered as a threshold allowable biological concentration of aluminium.

[Nervous system disorders induced by occupational exposure to aluminium compounds: a literature review]. / Zmiany w ukladzie nerwowym w nastepstwie narazenia zawodowego na zwiazki glinu w swietle pismiennictwa.

This is a review of the literature on the effect of aluminum (Al) and its compounds on the nervous system. The role of aluminum in etiology of some degenerative diseases of the nervous system, e.g. Alzheimer disease, amyotrophic lateral sclerosis or dementia, is presented. The special attention was turned to the effects of aluminum on the nervous system functions in persons occupationally exposed to metal-containing dusts and fumes, manifested mostly by neurobehavioral disorders and changes in the brain bioelectric functions and less frequently pronounced by clinical neurological symptoms.

Neurological and neurophysiological examinations of workers occupationally exposed to manganese.

The nervous system is the major target of the toxic effect of manganese (Mn) and its compounds. Nowadays, neurological diagnostics is directed towards early detection of symptoms and abortive forms, and the cases of serious damage of the nervous system are no longer reported. The aim of the present study was to assess the effects of manganese on the functions of the nervous system in workers exposed to this metal in the ship and electrical industries. The study covered a selected group of 75 male workers (mean age 39.17 yr +/- 9.79; range 20-56 yr), including 62 welders and fitters, as well as 13 workers involved in the battery production. Their employment duration ranged between 1 and 41 yr (mean 17.5 yr +/- 10.81). During the welding process the air Mn concentrations varied from 0.004 to 2.67 mg/m3 (arithmetic mean, 0.399 mg/m3; geometric mean, 0.154 mg/m3; standard deviation, 0.586). Of the 62 workers, 30 worked in the area with exceeding MAC value of 0.3 mg/m3. At the battery production workposts, Mn concentrations fell within 0.086-1.164 mg/m3 (arithmetic mean, 0.338 mg/m3, geometric mean, 0.261 mg/m3; standard deviation, 0.292). The values of current Mn exposure in the study group fell within the range below 0.01 and 2.67 mg/m3 (arithmetic mean, 0.4 mg/m; geometric mean, 0.15 mg/m3). Of the 13 subjects, 6 worked at the Mn air concentration exceeding MAC values. In the exposed group, the values of cumulated exposure index ranged from 0.008 to 35.52 (arithmetic mean, 8.045; geometric mean, 4.615; standard deviation, 6.562). The control group consisted of 62 men non-occupationally exposed to Mn, matched by sex, age and work shift distribution. Clinically, the increased emotional irritability, dysmnesia, concentration difficulties, sleepiness and limb paresthesia predominated among the disorders of the nervous system functions in workers chronically exposed to manganese. Neither in the central nor in the peripheral nervous system, the objective examinations revealed organic lesions that could provide grounds for diagnosing toxic encephalopathy or polyneuropathy. Generalized and paroxysmal changes were the most common recordings in the abnormal electroencephalography. Visual evoked potentials examinations showed abnormalities in the response evoked, which could be a signal of the optic neuron disorders and their significant relationship with cumulated exposure. The results of the study demonstrate that Mn exposure within the range of <0.01-2.67 mg/m3 (arithmetic mean, 0.4 mg/m3; geometric mean, 0.15 mg/m3) induces subclinical effects on the nervous system.

[Diagnostic neurologic procedures and certification in persons chronically exposed to carbon disulfide in light of personal cases]. / Neurologiczne postepowanie diagnostyczne i orzecznicze u osób narazonych na przewlekle dzialanie dwusiarczku (disiarczku) wegla w swietle wlasnych przypadków.

Carbon disulfide is a poison of particularly neotropic properties. In order to diagnose chronic occupational intoxication with carbon disulfide, a very careful examination of the central and peripheral nervous systems in required. The presence of subjective disorders only does not as yet provide grounds for diagnosing chronic intoxication. Organic changes like chronic encephalopathy or polyneuropathy after excluding the so called 'idiopathic' neurological diseases, may serve as a basis for certifying occupational disease.

[Assessment of the hearing system in workers chronically exposed to carbon disulfide and noise]. / Ocena stanu sluchu u pracowników narazonych na przewlekle dzialanie dwusiarczku wegla i halasu.

Epidemiological studies carried out in the years 1984-1993 revealed carbon disulfide (CS2) to be one of the major chemical occupational hazards. Whereas among physical factors, noise was found to be the most common threat. Industrial workers very often face a combined exposure of two or more factors, like CS2 and noise, responsible for significant biological risk to the human health, although health effects of such an exposure have not as yet been thoroughly recognized and explored. The aim of this study was to assess changes in the hearing system in people exposed to toxic effect of CS2, recognized as characteristic of an overall clinical history of chronic poisoning by this solvent, in cases of concomitant exposure to noise exceeding maximum allowable levels. The study covered 80 workers aged 44-65 years (mean = 44.9 +/- 5.1), employed in a spinning mill of viscose fibre for 20.3 years on average (+/- 5.4 years) with clinically observed chronic CS2 poisoning, and a group of 40 people (mean age = 56.8 years) exposed to CS2 but without subjective or objective symptoms indicating chronic poisoning by the solvent. Both groups of subjects at similar age and with almost the same duration of employment were exposed to CS2 in concentrations changing in time between 10 and 35 mg/m3 (mean concentration = 25.8 mg/m3), and to continuous noise with the level ranging from 88 to 92 dB(A) for six hrs per one shift. The control group was composed of 40 workers (mean age = 52.0 +/- 5.3 years) employed in the cotton industry plant, without contact with CS2 or other chemicals and working in the acoustic environment with similar level of exposure to noise (86-93 dB(A)). Audiological and electronystagmographic examinations revealed bilateral retrocochlear hearing impairment associated with symptoms of the central vestibular syndrome in 97.5 subjects with diagnosed chronic CS2 poisoning. In workers free from clinical symptoms of chronic CS2 poisoning, perceptive hearing impairment of various degrees was found, including retrocochlear in 45% of subjects and cochlear in 32.5%, while in 22.5% of those under study normal hearing was observed. In the control group of subjects exposed to noise without contact with CS2, sensorineural cochlear hearing loss, typical of chronic acoustic trauma without concomitant vestibular disorders, was revealed. The results of the study show that in subjects with diagnosed chronic CS2 poisoning and exposed to noise, hearing impairment and vestibular disorders occur in the form of central changes which suggests a dominating CS2 toxic effect on the hearing system. But in some people exposed to both CS2 and noise, the hearing impairment in localised in cochlea like in acoustic trauma damage. This probably depends on individual susceptibility to harmful effect of these factors.

[Acute poisoning by carbon monoxide affecting the extrapyramidal system]. / Ostre zatrucie tlenkiem wegla z zajeciem ukladu pozapiramidowego.

A case record of a 19-year old women acutely poisoned by carbon monoxide is presented. The state of the patient was very serious with loss of consciousness, cerebral oedema and acute circulatory failure, manifested by pulmonary oedema. The presence of carboxyhemoglobin in concentration of 45% was found in the blood. During the second week after the incident, extrapyramidal symptoms, manifested by hyperkinetic-hypokinetic syndrome with predominant involuntary movement, was observed. The diagnostic examinations of the central nervous system showed necrosis of globus pallidus, external capsule and a part of internal capsule.

[Methodologic guidelines related to neurologic and neurophysiologic examinations in a population occupationally exposed to carbon disulfide (CS2)]. / Wskazówki metodyczne dotyczace badan neurologicznych i neurofizjologicznych w populacji narazonej zawodowo na dwusiarczek wegla (CS2).

A range of neurological and neurophysiological examinations of persons chronically exposed to carbon disulfide (CS2), together with appropriate methods were presented. The principles of the subjective and objective examinations of persons suspected to be chronically exposed to CS2 were discussed. A characteristic syndrome of subjective symptoms with their neurasthennic and polyneuropathic nature was highlighted. The usefulness of neurophysiological examinations in the diagnosis of chronic CS2 poisoning, and particularly the value of the brain evoked potentials, were evaluated.

[Some issues regarding the use of electroencephalography and brain evoked potentials in occupational medicine]. / Niektóre zagadnienia zastosowania badan elektroencefalograficznych i badan mózgowych potencjalów wywolanych w praktyce medycyny pracy.

On the basis of the literature data, the practical value of electroencephalography (EEG) and tests of brain evoked potentials, particularly visual evoked potentials (VEP) and somatosensory evoked potentials (SSEP) in the diagnosis of occupational diseases of the nervous system is discussed. Electroencephalographic changes and the results of the evoked potential tests performed in persons exposed to organic solvents and heavy metals are analysed. The author postulates how the research in this field should be oriented and stresses the need to incorporate the method of evoked potentials into diagnostic procedures, especially in the case early symptoms of the nervous system dysfunction induced by occupational factors.

Rhythm patterns of basic brain bioelectric activity in workers chronically exposed to carbon disulfide.

The work aimed at defining the pattern and frequency of rhythm disturbances in basic brain bioelectric activity in EEG recordings, routinely regarded as normal, in workers exposed to chronic carbon disulfide (CS2) poisoning, without detected symptoms of organic lesions in the nervous system. The study covered 188 viscose spinners occupationally exposed to changing concentrations of CS2 vapours whose mean annual results of measurements ranged between 10 and 35 mg/m3, and the mean individual exposure fell within the range of 9.9-41.6 mg/m3 (mean--25.8 mg/m3). The frequency of alpha rhythm was analysed in EEG recordings with exclusive or nearly exclusive alpha rhythm in two groups studied. The presence or absence of subjective symptoms was taken as a criterion for the selection of subjects. Group I was composed of 116 subjects with subjective symptoms. Group II consisted of 72 workers with neither subjective nor objective symptoms. The age in group I ranged from 26 to 65 years (mean, 48.7 years), and the duration of employed from 5 to 39 years (mean, 23.3 years). The complaints reported were of neurasthenic and polyneuropathic type. The age in group II ranged from 28 to 63 years (mean, 49.4 years), the duration of occupational exposure accounted for 8-43 years (mean, 25.6 years). The control group included 194 persons with EEG routinely regarded as normal, matched by gender, age and work shift distribution. The subjects in Group I reported most frequently the following complaints: headache (72.4%), vertigo (48.3%), increased emotional irritability (42.2%), dysmnesia (36.2%), sleep disorders (27.6%), concentration difficulties (25.9%), limb pains (36.2%) and paraesthesia (27.6%). In the groups of subjects chronically exposed to CS2, both with subjective neurological symptoms, and without subjective or objective neurological symptoms, EEG recordings, routinely regarded as normal, did not reveal constant and symmetrical frequency of alpha rhythm waves. EEC recordings in the CS2 exposed workers with subjective neurological symptoms revealed almost constant frequency (12.9%) or slightly fluctuating frequency (41.4%) in 54.3% of subjects. In 45.7% of subjects considerable fluctuation of alpha rhythm frequency at the range of 3-4 Hz was found. Frequency disturbances applied to both sides, however, they were more pronounced in the leftside leads. Statistical analysis showed, neither in Group I nor in Group II, significant relationship between the pattern of alpha rhythm frequency fluctuations, the duration of CS2 exposure and the cumulative exposure index. Substantial and asymmetric fluctuations of alpha rhythm frequency found in the exposed group of subjects with subjective symptoms were considered as subclinical disturbances in the function of the central nervous system.

Neurological and neurophysiological examinations of workers occupationally exposed to organic solvent mixtures used in the paint and varnish production.

The aim of this work was to examine the nervous system of workers chronically exposed to mixtures of organic solvent at concentrations within or slightly exceeding the MAC values, used in the manufacture of paints and lacquers. The tests were performed on a group of 175 people, 107 men aged 22-59 (x = 41.25), and 68 women aged 20-55 (x = 38.62). The period of employment was x = 17.34 years and cumulative dose index 16.97 for males; for females, the corresponding values were x = 14.75 and x = 11.42, respectively. The control group included 175 people (107 men and 68 women) not exposed to chemicals matched according to sex, age, and work shift distribution. The neurological examinations included subjective and objective examinations of the nervous system, electroencephalographic (EEG) and visual evoked potential (VEP) evaluations. The assessment of organic solvent exposure was performed according to the method described in PN89/Z-04008/07, and the solvent mixtures were shown to contain xylenes, ethyltoluenes, trimethylbenzenes, propylbenzene, ethylbenzene, toluene, aliphatic hydrocarbons and the components of painter's naphtha. The most frequent complaints among the exposed males included headache, vertigo, concentration difficulties, sleep disorders, sleepiness during the day, increased emotional irritability, mood swings with a tendency to anxiety. The objective neurological examinations did not reveal organic lesions in the central or peripheral nervous systems. Generalised and paroxysmal changes were most common recordings in the abnormal EEG. VEP examinations revealed abnormalities, primarily in the latency of the response evoked. The results of this study suggest that exposures to concentrations within MAC values, or below 1.5 of the MAC values of organic solvents mixtures used in the manufacture of paints and lacquers produce subclinical health effect in the nervous system.

[Changes in the nervous system during occupational exposure to manganese in light of the literature]. / Zmiany w ukladzie nerwowym w przebiegu narazenia zawodowego na mangan (Mn) w swietle pismiennictwa.

Mental and neurological disorders in chronic poisoning by manganese belong to the most acute symptoms of occupational neurointoxication. As literature review shows different structures of the central nervous system may be damaged. Acute disorders of the nervous system are no more observed in manganese poisoning, and now the neurological diagnosis is directed towards detection of early abortive symptoms and forms. The use of neurophysiological examinations and imaging methods helps to detect preclinical changes in the nervous system providing that exposure is confirmed and other neurological diseases excluded.

[Neurologic and neurophysiologic evaluation of workers occupationally exposed to mixed organic solvents. Preliminary study]. / Neurologiczna i neurofizjologiczna ocena pracowników zawodowo narazonych na mieszaniny rozpuszczalników organicznych. Doniesienia wstepne.

The study covered 72 persons (39 females and 33 males), engaged in the production of dyes and varnishes, and exposed to mixtures of organic solvents which contain benzene C-9 and C-10 alkyl derivatives. For females--length of employment accounted for mean = 15.9 years and cumulative exposure index for mean = 12.11, and for males - mean = 16.4 years and mean = 12.17, respectively. The study results applying to the group exposed were compared with the results of the controls matched according to gender, age and work shifts. Clinical examination indicated that among complaints the following manifestations predominated: headache, dizziness, increased emotional excitability, memory and concentration disturbances, hypersomnia during a day and mood instability. Subjective symptoms were more frequently observed in females. Neurological examination revealed no organic changes neither in the central nor in the peripheral nervous system. Certain anomalies were noted in EEG and visual evoked potential (VEP) examinations which may indicate pre-clinical changes in the nervous system.

[Neurologic diagnosis and certification in persons chronically exposed to certain organic solvents in light of personal cases]. / Neurologiczne postepowanie diagnostyczne i orzecznicze u osób narazonych na przewlekle dzialanie niektórych rozpuszczalników organicznych w swietle wlasnych przypadków.

A clinical picture of selected cases diagnosed or suspected of chronic poisoning by organic solvents such as: Trichlorethylene (TRI), Tetrachlorethylene (PER), Carbon Disulfide (CS2) is presented. Based on examples of diagnosed neurological syndromes, some diagnostic and certification issues concerning occupational diseases of the neurological system, are analysed. An objective assessment of patients' complaints, differentiation between occupational diseases, so called idiopathic diseases of the nervous system, selection of appropropriate diagnostic methods in order to confirm or exclude these diseases belong to essential problems among those discussed.

[The picture of visual evoked potentials in Kimmerle anomaly]. / Obraz wzrokowych potencjalów wywolanych w anomalii Kimmerle'go.

Visual evoked potentials (VEP) were studied in 16 persons with radiological confirmed Kimmerle anomaly. Each eye was stimulated by the reversible checker-board pattern using the reversal and flash stimulation methods. Abnormal responses were noted in about 75% of the studied patients. Latency disturbances prevailed during reversal stimulation and abnormal configuration of responses predominated during flash stimulation.

[Back pain syndromes in dentists. Diagnosis and differential diagnosis]. / Zespoly bólowe kregoslupa u stomatologów. Zagadnienia diagnostyki i róznicowania.

The literature evaluating the occurrence of back pain syndrome in dentists was reviewed. The data aggregated provide an evidence that cervical and lumbosacral pains are the most common complains as far as the locomotor system is concerned. Principles of diagnosis and identification of symptoms among other diseases were discussed.

[Analysis of the basic bioelectric action of the brain in workers chronically exposed to certain organic solvents]. / Analiza podstawowej czynnosci bioelektrycznej mózgu u pracowników narazonych na przewlekle dzialanie niektórych rozpuszczalników organicznych.

The bioelectric action of the brain was analysed by means of EEC examination with an exclusive or almost exclusive alpha rythm in workers chronically exposed to tetrachloroethylene and in workers exposed to the mixture of solvents which contain aliphatic derivatives of benzene with nine or ten carbon atoms. The study covered 30 male workers of the similar age group, period of employment and work shifts. No symptoms of the nervous system damage were observed. There were either no significant differences in the frequency of alpha rythm according to EEC examination in workers exposed to organic solvents when compared with controls.

[Certain diagnostic-certification problems in workers exposed chronically to carbon disulfide]. / Niektóre problemy diagnostyczno-orzecznicze u pracowników narazonych na przewlekle dzialanie dwusiarczku wegla.

The results of examinations of workers employed in manufacturing of chemical fibres were analysed. The study covered 378 workers of mean age between 49.9 and 52 years, employed at different working posts. A chronic exposure to carbon disulfide (CS2) ranged from 19.4 to 23.4 years, on average. The diagnosis of chronic intoxication with CS2 was mainly based on pathological changes observed in the nervous system such as encephalopathy, polyneuropathy and encephalo-polyneuropathy. Encephalopathy was most common and it was observed in 35.4% of patients and the mixed syndromes were found in 25%. Greatest difficulties were encountered in the diagnosis and health certification of chronic CS2 intoxication manifested by the pseudoneurotic syndrome and the sensory polyneuropathy.

[Current state of studies on the effect of organic solvents on the nervous system]. / Stan badan nad wplywem rozpuszczalników organicznych na uklad nerwowy.

Current problems of clinical neurotoxicology, particularly the effect of organic solvents on the nervous system functions have been discussed. A review of the literature on the neurophysiological methods for use in toxicology been presented. Special attention has been paid the usefulness of evoked potential testing for detecting early changes in the nervous system caused by action of neurotoxic chemicals.

[Neurobehavioral effects of chronic occupational exposure to mixtures of solvents used in furniture varnishing. Part II--Testing of visual evoked potentials]. / Neurobehawioralne skutki przewleklego narazenia zawodowego na mieszaniny rozpuszczalników stosowanych w lakierowaniu mebli. Czesc II--Badania wzrokowych potencjalów wywolanych.

The study involved a group of 40 workers chronically exposed to mixtures of organic solvents. The exposure did not exceed the allowed hygienic standard. Organic changes in the central and/or peripheral nervous system were not detected. Irregular visual evoked potentials were found in 9 (22.5%) of the exposed workers. The irregularities related primarily to the latency of some components of visual evoked potentials. Those changes occurred primarily within the group of workers employed for longer periods of time (16 years and longer).

[Visual and mathematical analysis of background cerebral bioelectric activity in cases of vascular headache (a question of rhythmicity)]. / Analiza wizualna i matematyczna podstawowej czynnosci bioelektrycznej mózgu w przypadkach naczynioruchowych bólów glowy (zagadnienia rytmicznosci).

The visual and mathematical analysis (computer assisted) of the background cerebral activity in patients with vasomotor headaches, including common vasomotor headaches, Horton's headache and migrainous headache showed statistically significant fluctuations of the frequency of the background cerebral bioelectric activity only in patients with migrainous headaches. Of interest was the observed evident asymmetry of the alpha rhythm frequency. This indicates that the background bioelectric cerebral activity is arrhythmic and asymmetrical in patients with migrainous headaches.