[Acute methanol poisoning among patients of Toxicology Unit, Nofer Institute of Occupational Medicine in Łódź, during the period 2000-2009]

The main objective of this study was an analysis of the cohort of patients hospitalized due to intoxication with this agent during the period 2000-2009 and investigate factors, which determined the course of poisoning. During the search process, 288 (1.07%) patients were identified within total number of 26801 patients hospitalized. Within analysed cohort male patients formed majority with 227 males, whereas only 61 females were found within this group. The mean methanol blood concentration was 50.09 mg/dl and ethanol - 292.90 mg/dl. Patients condition on admission varied, the most frequently noted pathologies were consciousseness disturbances and tachycardia, namely the former was recorded in 171 cases (59.4%) whereas the latter in 89 patients (30.90%). 11 patients died within the analysed group and 72 developed single or multiorgan complications in the course of poisoning. The most commonly encountered complication was pneumonia. Features of central nervous system (CNS) damage were found in 20 cases (6.94%). Average concentrations of methanol in the group of the 11 deceased patients were: 158.73 mg/ dl, 20.91 mg/dl for ethanol. The average values of arterial blood gases parameters in this group were pH= 6.98; BE=(-) 22.482; HCO3=9.67 mmol/l. Within the non survivors group such complications as CNS damage, seizures, pneumonia, liver injury and pancreatitis were noted more frequently, with statistical significance. The concentrations of methanol and ethanol in the blood on admission and such ABG parameters as pH, BE, HCO3, pCO2 i pO2 also measured on admission should be considered as the prognostic factors, determining the course of the disease and the outcomes of treatment. Poor prognosis may be associated with such clinical features on admission, as: respiratory and circulatory disturbances and cerebral sequelae.

Diagnostic value of voice acoustic analysis in assessment of occupational voice pathologies in teachers

It has been shown that teachers are at risk of developing occupational dysphonia, which accounts for over 25% of all occupational diseases diagnosed in Poland. The most frequently used method of diagnosing voice diseases is videostroboscopy. However, to facilitate objective evaluation of voice efficiency as well as medical certification of occupational voice disorders, it is crucial to implement quantitative methods of voice assessment, particularly voice acoustic analysis. The aim of the study was to assess the results of acoustic analysis in 66 female teachers (aged 40-64 years), including 35 subjects with occupational voice pathologies (e.g., vocal nodules) and 31 subjects with functional dysphonia. The acoustic analysis was performed using the IRIS software, before and after a 30-minute vocal loading test. All participants were subjected also to laryngological and videostroboscopic examinations. After the vocal effort, the acoustic parameters displayed statistically significant abnormalities, mostly lowered fundamental frequency (Fo) and incorrect values of shimmer and noise to harmonic ratio. To conclude, quantitative voice acoustic analysis using the IRIS software seems to be an effective complement to voice examinations, which is particularly helpful in diagnosing occupational dysphonia.

[Poisoning with weever fish venom: a case report]

Poland's access to the EU causes that there is the risk of poisoning from sources outside Poland. This is confirmed by the case reported below. The Weeverfish Trachinus draco lives in the coastal waters of West Africa and Europe (including those of the Mediterranean Sea) and belongs to the most poisonous fish species. The venom of Trachinus draco contains proteins that cause cellular membrane depolarisation, and haemolysis. A 35-yr. man was admitted to the Toxicological Department of the Nofer Institute of Occupational Medicine for symptoms, such as: a strong pain, swelling and reddening of the left leg, that had appeared after contact with an unidentified fish when he had been enjoying a bath in the Mediterranean Sea. In the additional examinations, slight abnormalities were detected only in the results of blood agglutination test. The patient was discharged from the hospital 7 days later in good condition.

The effectiveness of voice therapy for teachers with dysphonia

OBJECTIVE

An incorrect voice emission is a risk factor for developing occupational voice disorders. The study aimed at assessing the effectiveness of voice therapy in female teachers with dysphonia.

METHODS

The study comprised 133 subjects with voice disorders, taking part in a vocal training programme. A reference group for the present study included 53 teachers with dysphonia. Questionnaire surveys, phoniatric examination and videostroboscopic evaluation were conducted at initial and control examination.

RESULTS

In the study group, an improvement after the vocal training was noted in most of the reported symptoms and also in some quantitative parameters of phoniatric examinations compared to the findings for the reference group. The number of patients who assessed their voice as normal increased significantly after the vocal training (2.3 vs. 46.6%). A significant increase in the mean maximum phonation time, from 13.3 to 16.6 s, was observed. The same applied to voice frequency range (increase from 171 to 226.8 Hz).

CONCLUSIONS

The outcomes of vocal training, such as a subjective improvement of voice quality and an increase in the quantitative parameters (prolonged maximum phonation time, extended voice range) seem to be important parameters for monitoring the effectiveness of training in correct voice emission.

[The application of 4-aminopyridine in calcium channel inhibitors acute poisoning]

Calcium channel inhibitors have been extensively used to treat arterial hypertension, ischaemic heart disease and supraventricular rhythm irregularities. The poisonings by that category of drugs are extremely dangerous, particularly when accompanied by intoxication with other drugs affecting the circulatory function. This paper reports 3 cases of poisonings with calcium channel inhibitors (verapamil and diltiazem) in combination with angiotensin convertase inhibitors and nonselective beta-adrenolytics. Circulatory insufficiency and cardiac rhythm abnormalities were noted in all reported cases, in one in the form of ventricular bigeminy and two episodes of ventricular fibrillation, while in the two other cases in the form of 1 degree atrioventricular block. The persisting hypotonia combined with heart rhythm disturbances could not be prevented by the typical conservative treatment involving intravenous administration of infusion fluids, calcium formulations, catecholamines and atropin. The application of 4-amino-pyridine (Pymadin) caused that arterial tension and heart rate were higher, and the heart rhythm disturbances disappeared. The reported cases suggest a beneficial effect of 4-aminopyridine used to treat cases of poisonings by calcium channel inhibitors; however, up to the present time, no detailed procedures have been determined for 4-aminopyridine administration in cases like those reported above. 4-aminopyridine has not been included in the list of the antidotes approved by the WHO and, therefore, broader tests and more clinical observations are required to confirm its therapeutic value.

[Diagnostics of occupational voice diseases following the amendment of the Polish Occupational Diseases Certification Act]

BACKGROUND

The aim of the study was to assess whether the amended Polish Occupational Diseases Certification Act of 2002 has made an impact on the medico-legal process of the occupational voice diseases certification.

MATERIAL AND METHODS

Nationwide reports on the number and types of occupational diseases diagnosed in Poland in 1999-2004, and the medical records of 267 teachers diagnosed for the occupational voice organ disease were analyzed.

RESULTS AND CONCLUSIONS

A 4-fold gradual and continuous reduction (from 3521 to 881 cases) in the number of registered occupational voice diseases was noted in 1999-2004, which was not really associated with the date the amended Act came into force. The patients challenging the first instance refusals issued after 2002 were characterized by significantly worse phoniatric and videostroboscopic indices than those consulted before that date. Before 2002, the percentage of the second instance positive decisions, changing the first instance refusals was over 16%, while after 2002 the corresponding number was only 5%. This indicates that a consensus of decisions issued by the first and second instances has significantly increased since the amended Act came in effect.

The Prevalence and Risk Factors for Occupational Voice Disorders in Teachers

OBJECTIVE

Occupational voice disorders in Poland account for over 25% of all occupational diseases. The aim of the study was to assess the prevalence of voice problems in the general population of Polish teachers, and identify risk factors for developing voice pathology.

PATIENTS AND METHODS

The study group comprised 425 female full-time teachers (most of them primary and secondary school, age ranging from 23 to 61 years) and 83 non-teacher women (control) whose jobs did not involve vocal effort, matched for age to the study group. All participants were subjected to a survey using an extensive questionnaire, and to laryngological, phoniatric and videostroboscopic examinations.

RESULTS

The overall lifetime vocal symptoms were more frequent in the teachers than in the non-teachers (69 vs. 36%), and in particular it related to permanent and recurrent hoarseness, and dryness in the throat. Mean number of the voice symptoms was 3.21 in teachers and 1.98 in controls (p < 0.001). Abnormal (non-euphonic) voice, neck muscle hypertension during phonation and incorrect resonator function were also significantly more frequent in the teachers. Mean maximum phonation time was shorter in teachers than in the controls (14.3 vs. 15.9 s, p < 0.01). Occupational voice disorders and hyperfunctional dysphonia (that is thought to predispose to such pathology) were found in 32.7% of teachers and 9.6% of control subjects. The probability of developing incomplete glottal closure (odds ratio 13.2x; 95% CI: 1.8-96.8) and hyperfunctional dysphonia (odds ratio 2.7; 95% CI: 1.14-6.44) were significantly higher in the teacher group versus non-teachers. A significant positive relationship was found in teachers between the prevalence of hyperfunctional dysphonia and strained phonation, neck muscle hypertension, instability of voice, self-assessed hyper-arousal, and lifetime vocal effort index (years of employment as a teacher x hours of professional activity/week). The prevalence of vocal nodules and incomplete glottal closure were correlated with incorrect phonation technique parameters, but not with psychological factors. No correlation was found with environmental variables, such as classroom temperature, humidity, airborne dust.

CONCLUSION

The prevalence of self-reported symptoms and clinical signs of voice disorders is around 2-3 times more frequent in Polish female teachers than in non-teachers. Lifetime vocal effort, incorrect technique of phonation and psychological predisposition seem to constitute major risk factors for developing occupational voice disorders.

Exacerbation of noise-induced hearing loss by co-exposure to workplace chemicals

BACKGROUND

: Numerous organic solvents applied in industry, like toluene, styrene, xylene and n-hexane have been demonstrated to impair hearing in animals. However, the effects of exposure to a given organic solvent and the interaction of noise and solvents on hearing in humans are still not fully recognized.

STUDY DESIGN

: The study was aimed to assess the effects of occupational exposure to solvents alone or in combination with noise on hearing in 1117 employees of yacht, ship, plastic, shoe, and paint and lacquer industry. These persons were exposed either to the mixture of organic solvents with xylene as the main component, or predominantly to styrene, or to the mixture of n-hexane and toluene. Detailed questionnaire data and pure-tone audiometry were compared with data of the reference group that included white collar workers, exposed neither to solvents nor noise and metal factory workers exposed to noise only. In all statistics, the confounding factors were recognized as gender, age, exposure to noise, and other variables occurring at a different rate in study and reference group.

RESULTS

: Odds ratio (OR) of hearing loss related with the particular exposure to chemicals was 2.4 (95%CI 1.59-3.74) in case of solvent mixture, 3.9 (95%CI 2.4-6.2) in case of styrene and 5.3 (95%CI 2.6-10.9) in case of n-hexane and toluene exposure. The odds of developing hearing loss substantially increased in the case of combined exposure to organic solvents and noise as compared to isolated exposure to each of these hazards. The highest OR (over 20-fold) was demonstrated in subgroups of subjects exposed simultaneously to noise and two ototoxic solvents (i.e. styrene and toluene or n-hexane and toluene). The mean hearing thresholds were significantly higher in the solvent-exposed groups than in the reference group. The differences in thresholds were observed at high frequencies in the solvent mixture- and n-hexane + toluene-exposed groups and at all frequencies in the styrene-exposed group. A positive linear relationship existed between exposure to solvents and hearing thresholds at high frequencies.

CONCLUSIONS

: The results of the study provide the epidemiological evidence that exposure to organic solvents in humans is associated with an increased risk of hearing loss. The simultaneous exposure to organic solvents and noise seems to enhance the hearing deficit if compared with isolated exposures.

[Assessment of voice acoustic parameters in female teachers with diagnosed occupational voice disorders]

BACKGROUND

Laryngovideostroboscopy is the method most frequently used in the assessment of voice disorders. However, the employment of quantitative methods, such as voice acoustic analysis, is essential for evaluating the effectiveness of prophylactic and therapeutic activities as well as for objective medical certification of larynx pathologies. The aim of this study was to examine voice acoustic parameters in female teachers with occupational voice diseases.

MATERIALS AND METHODS

Acoustic analysis (IRIS software) was performed in 66 female teachers, including 35 teachers with occupational voice diseases and 31 with functional dysphonia.

RESULTS

The teachers with occupational voice diseases presented the lower average fundamental frequency (193 Hz) compared to the group with functional dysphonia (209 Hz) and to the normative value (236 Hz), whereas other acoustic parameters did not differ significantly in both groups.

CONCLUSIONS

Voice acoustic analysis, when applied separately from vocal loading, cannot be used as a testing method to verify the diagnosis of occupational voice disorders.

Effects of Coexposure to Noise and Mixture of Organic Solvents on Hearing in Dockyard Workers

Questionnaire and audiometric data of 701 dockyard workers (517 noise and organic solvent mixture-exposed and 184 noise-only-exposed) were referred to 205 control subjects not exposed to either noise or solvents. The odds ratio (OR) of hearing loss was significantly increased by approximately 3 times in the noise-only group and by almost 5 times in the noise and solvent group. A moderate effect of solvent ototoxicity, in addition to noise, was observed on hearing threshold at a frequency 8 kHz. ORs for hearing loss were 1.12 for each increment of 1 year of age, 1.07 for every decibel of lifetime noise exposure (dB-A), and 1.004 for each increment of the index of lifetime exposure to solvents. The results suggest an additive damaging effect of coexposure to noise and organic solvents to the auditory organ.

Temporary changes in hearing after exposure to shooting noise

OBJECTIVES

Firearm is a common source of impulse noise that may potentially damage hearing organ. It has been suggested that otoacoustic emissions, particularly transient-evoked otoacoustic emissions (TEOAE), might be more sensitive than pure-tone audiometry (PTA) in the assessment of changes to cochlea caused by noise. The aim of this study was to: (i) evaluate exposure to impulse noise from small-caliber weapons, (ii) compare the post-exposure changes in hearing measured by PTA and TEOAE and correlate them with noise parameters.

MATERIALS AND METHODS

The study included 18 male hunters (group I) and 28 candidate policemen (group II) exposed to impulse noise from small firearms during target practices. Group I was unprotected during shooting, whereas group II used commonly available hearing protectors. PTA and TEOAE were performed before and 2-10 min after shooting. Exposure to impulse noise was evaluated by in situ measurements.

RESULTS

Groups I and II were exposed to 3-4 and 4-144 impulses of noise at mean C-weighted peak sound pressure levels of 154 dB and 156 dB, respectively. No post-exposure audiometric threshold shift was observed in group I. Significant reductions of TEOAE levels were found both for the whole response (-2.2 dB SPL) and for 1/2 -octave band responses in the frequency range of 1000-4000 Hz (from -1.6 to -3.0 dB SPL). These changes were not correlated with C-weighted peak sound pressure levels or equivalent-continuous A-weighted sound pressure level. Significant correlation was found for peak sound pressure and maximum sound pressure levels in 1/3-octave bands in the frequency range corresponding with the main part of the acoustic energy of impulses (correlation coefficients r from -0.58 to -0.77, p < 0.05). In group II neither PTA nor TEOAE showed significant hearing impairment after shooting.

CONCLUSIONS

The results show that even short-term exposure to impulse noise from small-calibre firearms might cause temporary hearing impairment measured by TEOAE. Therefore, the use of earmuffs is strongly recommended, because most of them seem to effectively attenuate impulse noise from small-calibre firearms.

Ototoxic effects of occupational exposure to styrene and co-exposure to styrene and noise

Ototoxicity of styrene and the synergistic action of styrene and noise have been shown in rats. The respective data in humans are scarce and equivocal. This study evaluated the effects of occupational exposure to styrene and combined exposures to styrene and noise on hearing. The study group, comprised of 290-yacht yard and plastic factory workers, was exposed to a mixture of organic solvents, having styrene as its main compound. The reference group, totaling 223 subjects, included (1) white-collar workers, exposed neither to solvents nor noise and (2) metal factory workers, exposed exclusively to noise. All subjects were assessed by means of a detailed questionnaire and underwent otorhinolaryngological and audiometric examinations. Multiple logistic regression analysis revealed almost a 4-fold (or 3.9; 95% CI = 2.4-6.2) increase in the odds of developing hearing loss related to styrene exposure. The factors adjusted for were: age, gender, current occupational exposure to noise, and exposure to noise in the past. In cases of the combined exposures to styrene and noise, the odds ratios were two to three times higher than the respective values for styrene-only and noise-only exposed subjects. The mean hearing thresholds--adjusted for age, gender, and exposure to noise--were significantly higher in the solvent-exposed group than in the unexposed reference group at all frequencies tested. A positive linear relationship existed between an averaged working life exposure to styrene concentration and a hearing threshold at the frequencies of 6 and 8 kHz. This study provides the epidemiological evidence that occupational exposure to styrene is related to an increased risk of hearing loss. Combined exposures to noise and styrene seem to be more ototoxic than exposure to noise alone.

[Effect of voice emission training on the improvement in voice organ function among students attending the college of teachers]

One of the major causes of frequent voice disorders in teachers is incorrect vocal emission technique. The aim of the study was to assess the effect of logopedic training on voice emission parameters and vocal organ disorders in students attending the college for teachers. The study group comprised 45 female students who experienced vocal abnormalities after excessive vocal effort. Questionnaire surveys, phoniatric and videostroboscopic examinations were performed in all subjects before starting and after completing the logopedic training. The training was preceded by a theoretical seminar on voice organ anatomy, physiology, and hygiene. The logopedic training lasting two-three months contributed to the improvement in voice characteristics and the condition of voice organ in the majority of students, as well as in phoniatric parameters, including the increase in the maximum phonation time, the frequency range of voice, the reduction of the glottal insufficiency and the elimination of "soft" vocal nodules. The results of the study indicate that the implemented voice emission training improved significantly voice quality and allowed for providing an efficient therapy of already existing functional disorders of the larynx.

[Hearing impairment in the plastics industry workers exposed to styrene and noise]

Styrene exerts ototoxic effect in animals, and the combined exposure to this solvent and noise produces a synergistic effect relative to the isolated exposure to noise. However, there is a lack of reliable evidence that chronic occupational exposure to styrene is ototoxic to humans. Neither has been documented its additive effect with noise. The present study was aimed to assess hearing impairment and the risk of hearing loss in workers exposed to both styrene and noise. The study group included 72 male workers occupationally exposed to styrene in the plastics industry. The results were compared with two control groups, matched by age, gender and personal traits: one group composed of 82 male workers employed in a printing house and exposed only to noise at the levels almost twice as high as those observed in the group exposed to styrene and noise, and the other consisted of 65 male workers exposed neither to solvents nor to noise at workplace. In the group exposed to styrene and noise, significantly increased average hearing loss, as compared to both control groups, was found at all frequencies (1-8 kHz). The risk of hearing loss in the group exposed to styrene and noise was seven times higher (RR: 6.6; 3.0-15.9) than in the non-exposed group, and four times higher (RR: 4.0; 1.8-9.1) than in when workers exposed only to noise. However, no relationship could be observed between the amount of styrene exposure and hearing impairment, taking account of the confounding effect of noise and age. The results of the study suggest that the exposure to solvent mixtures with styrene as a basic component may exert additional, to noise, adverse effect on the auditory organ.

Hearing loss among workers exposed to moderate concentrations of solvents

OBJECTIVES

It is known that some industrial organic solvents are ototoxic. This study was aimed at evaluating the hearing effects of a mixture of organic solvents alone or in combination with noise on employees in paint and lacquer enterprises. The concentration of solvents was below the occupational exposure limits (OEL) for most of the subjects.

METHODS

Altogether 517 subjects were divided into the following three groups: persons with no risk due to noise or organic solvent exposure at the workplace, workers exposed to organic solvents only, and workers exposed to both organic solvents and noise.

RESULTS

The relative risk (RR) of hearing loss in the solvent-only exposure group was significantly increased (RR 4.4 and RR 2.8 for noise exposure of < 80 dB-A and < 85 dB-A, respectively) in a wide range of frequencies (2-8 kHz). No additional risk in the solvent + noise exposure group was found (RR 2.8). Hearing thresholds were significantly poorer in a wide range of frequencies (1-8 kHz) for both groups exposed to solvents, when compared with the reference group. The mean hearing thresholds at frequencies of 2-4 kHz were poorer for workers exposed to solvents + noise than for the solvent-only group; this finding suggests an additional effect for noise. However, there was no correlation between hearing loss and the extent of solvent exposure.

CONCLUSIONS

The results indicate that occupational organic solvent exposure at moderate concentrations increases the risk of hearing loss, and the ototoxic effects should be considered when the health effects of exposed workers are monitored.

[Evaluation of voice quality in students from teaching colleges]

Vocal disorders are very common occupation-related disease in teachers. Their remarkable incidence might be associated with inappropriate techniques of speech and poor vocal hygiene. The aim of this study was to assess the function of vocal organ including voice emission technique in persons starting their teaching occupation. The study group included 66 female students at Teaching College. Their were thoroughly interviewed and subjected to laryngological, phoniatric and videostroboscopic examinations. All subjects reported subjective symptoms after vocal effort. Hoarseness and throat dryness were the most common. In the majority of students functional vocal disorders were observed. In 30% of them insufficiency of glottis and in four (6.1%) students soft vocal nodules were found. Signs and symptoms of vocal diseases were more frequent in a subgroup of students exposed to increased vocal effort during their professional education. The results indicate that young teachers are not sufficiently prepared for increased vocal strain, apparently associated with their profession. It is indeed necessary to introduce preventive programs including special training of appropriate speech technique, into the curricula of schools for teachers.

[Assessment of hearing impairment in workers exposed to mixtures of organic solvents in the paint and lacquer industry]

Clinical and experimental studies indicate a possible harmful effect of chemicals, especially organic solvents, on the hearing system. In combined exposure to noise and solvents, very common in industry, it is most likely that a synergetic action of these factors enhances the traumatising effect of exposure to noise. The aim of this study was to assess the incidence and the risk of hearing impairment in 117 paint and lacquer factory workers exposed to a mixture of organic solvents. An analysis of organic solvent mixtures reveals that xylene and ethyl acetate are their major components whose concentrations depend on individual workposts. The control group consisted of 76 workers exposed to noise exceeding, Threshold Limit Value and 125 healthy subjects exposed neither to noise nor to solvents in their occupational setting. Pure tone audiometry revealed the highest hearing thresholds in workers exposed to solvents, lower thresholds in those exposed to noise, and the lowest ones in the non-exposed individuals. Hearing loss was found in 30% of workers exposed to organic solvents, in 20% of noise-exposed subjects, and in only 6% of non-exposed subjects. The comparison of relative risk values also indicated significantly enhanced probability of hearing impairment in workers of the paint and lacquer factory (9.6; 3.2-25.6), which is even more strongly pronounced than in the group of subjects exposed to noise (4.2; 1.2-13.2). An analysis of hearing impairment risk in particular frequencies suggests that organic solvents may damage the inner ear in much greater extent than noise. The results of the study show that exposure to organic solvents may create a significant risk of hearing impairment. Therefore, further steps should be taken to include the exposed population into effective preventive programmes.

[Cerebrospinal fluid prealbumins in children with subacute sclerosing panencephalitis]

In the cerebrospinal fluid of 26 children with SSPE the levels of prealbumins and total proteins were determined and electrophoretic separation of proteins was done. The usefulness is discussed of the percent proportion of prealbumins in the cerebrospinal fluid as a criterion indicating damage to the blood-cerebrospinal fluid barrier with increased penetration of proteins in SSPE. It is concluded that in diseases in which biosynthesis occurs of proteins in the central nervous system the percent proportion of prealbumins fails to reflect the integrity of the brain-cerebrospinal fluid barrier.