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PubMedDate not supplied

Application of mathematical modelling for assessing the urinary half-times of nickel in stainless steel welders.

The study regards workers employed in manual metal are welding of stainless steel (MMA/SS). For two weeks they collected their urine during the work shift and the 16 hours following in order to evaluate the kinetics of nickel. Using one-compartment mathematical modelling we calculated the values of the toxicant's urinary half life during the two phases of exposure and postexposure and also during non working weekends. The aim of the study was to find correlations between inhaled doses and excreted quantities and to acquire practical data for use in biological monitoring. In the welders the mean urinary half life in the exposure period was 59.5 hours, in the post exposure it was 95.6 hours, while in weekend it was 95.5 hours. The study showed that exposure to fumes containing nickel could determine the accumulation of the metal in slow elimination speed compartment. As a consequence of the accumulation of nickel in compartments with different elimination speeds, the collection of single urinary portions in biological monitoring seems to give little information about the actual exposure. In our opinion this indicates collecting urine samples throughout the entire work shift and the 16 hours following exposure.

Air Pollutants, Occupational↗
PubMed2006

[Altered systemic iron metabolism in welders exposed to manganese].

OBJECTIVE: To investigate the systemic changes of iron metabolism following manganese exposure. METHODS: Ninety-seven welders and 91 workers with no history of exposure to manganese were recruited from the same factory in Beijing serving as the exposure group and the control group respectively. The welding rods used were type J422. The concentration of the manganese in the air of the work place was determined respectively with the national standard method. The serum iron and manganese, ferritin, transferrin and transferrin receptors were measured with the graphite furnace atomic absorption spectrophotometry and ELISA in both groups. RESULTS: The permissible concentration-STEL of ambient Mn in welders' breathing zone ranged from 0.53 mg/m(3) to 2.19 mg/m(3), while the permissible concentration-TWA of ambient Mn was between 0.29 mg/m(3) and 0.92 mg/m(3) in the breathing zone of the workplace. Serum Mn and Fe concentrations in welders were about 1.40 times (P < 0.0l) and 1.2 times (P < 0.01), respectively, higher than those of control subjects. At the same time, the transferrin concentrations in serum were significantly higher (about 1.2 times, P < 0.05) in welders than in controls. In contrast, transferrin receptors were significantly lower (about 1.2 times) in exposed subjects than controls (P = 0.001). There was no difference in serum ferritin between the two groups (P = 0.112). Although there was no significant trend, the serum ferritin level was increased by 18% in comparison with that of the control. The abnormal percentage of serum Fe and Serum Mn in welders were 55.67% and 67.01% respectively, higher than those of control subjects. In addition, the correlations between all indicators and the duration of employment were not observed. CONCLUSION: The long term exposure to the manganese can induce the disorder of the iron metabolism, which is found in the expression of increase of the serum iron and transferrin as well as the decrease of transferrin receptors.

Female↗
PubMedDate not supplied

[Chronic exposure to styrene and psychiatric symptomatology: a case-control descriptive study].

BACKGROUND: Although the acute psychiatric consequences exerted by Styrene and other aromatic hydrocarbons are abundantly described, the effects produced by a low-dosages chronic exposure are not known, in spite of the wide employment in the field of industrial production. The aim of this study is to evaluate the psychiatric symptoms in a group of subjects exposed to styrene in comparison with a control group, not exposed to the substance. SUBJECTS AND METHODS: Twenty two qualified workers, divided into 11 subjects in charge of welding and resin tapping exposed to styrene, and 11 not exposed to neurotoxic substances, were evaluated through the Symptom Check List Revised (SCL-90-R), a scale for the global self-evaluation of psychiatric symptomatology. RESULTS: The statistical tests, herein utilized, showed a significant prevalence for the dimensions somatization and psychoticism in the exposed subjects to styrene as compared to the non-exposed subjects. CONCLUSIONS: The results of this study, although limited by the paucity of the sample, emphasize the importance of an early diagnosis and evaluation of the clinical predictors in subjects exposed to styrene. The relatively low concentration levels of styrene in the working area of the subjects exposed underlines the opportunity to arrange preventive evaluation strategies for a prompt intervention in those cases with a clear syndromic presentation.

Adult↗
PubMed1990

[Cataract in welders. Contribution of occupational exposure, references for recognition as an occupational disease and presentation of preventive measures].

An analysis was made of all the cases of eye disease in welders caused by infrared radiation which have been recognized as occupational disease Bk 52 in the GDR by now. A comparative study was conducted and proposals for the definition of criteria for recognition as occupational disease were derived. The determination of exposure by means of suitable radiation measurement devices is described. Both the problems of measurement value acquisition and the evaluation of radiation loads are dealt with. The infrared radiation load of the eyes is quantified for several frequently used welding techniques. Various measuring values obtained in other industries and in the transport sector are given for comparison. Protective measures and the use of suitable face protections are discussed. Conclusions are drawn with regard to the health protection of welders against infrared radiation exposure.

Cataract↗
PubMed1990

[Manifestations of excessive iron accumulation in steel and cast iron welders].

Welding of steel and cast iron leads to overaccumulation of iron in the welder's organism, which manifests itself in the iron content growth in the whole blood and serum, an increase of serum general iron binding ability, calcium homeostasis disorders, decrease of cardiac muscle contraction, progressing pneumoconiosis with concomitant characteristic pneumohemosiderosis features. The secondary preventive measures of the occupational pathology should include a set of drugs and preparations to improve the iron content in the organism and related metabolic disorders.

Bronchitis↗
PubMed1989

[Various occupational diseases of the eyes caused by ultraviolet radiation].

Studies are performed on 87 workers--electric welders (for some of them they continued several years), 68.9% of the subjects have been in contact with ultraviolet radiation for a period of more than 10 years (length of service). There are data for passed acute form of electric ophthalmia, average 6.11 times during the length of service in workers with length of service up to 10 years and 12.1 times in workers with length of service above 10 years. In 11.82% of the workers a chronic form of phtoophthalmia is observed. After observation, for the first time in this country is described specific radiation cataracta in 24.13% of workers--electric welders in contact with ultraviolet radiation during their length of service--above 10 years. The problem of cataractogenesis of ultraviolet rays in electric welding processes is discussed.

Adult↗
PubMed1989

Encephalopathy and vestibulopathy following short-term hydrocarbon exposure.

Dizziness, headaches, and weakness occurred among three men after short-term hydrocarbon exposure during improper welding procedures in a closed container. Symptoms were related to objective evidence of vestibular and cognitive dysfunction. Symptoms and abnormal test results persisted for 6 to 18 months. Simulation of the accident failed to demonstrate likely exposures except aliphatic hydrocarbons, well within the permissible exposure levels. Short-term exposures to neurotoxins may lead to long-term central nervous system abnormalities.

Accidents↗
PubMed1989

Measurement of pulp temperature increase to externally applied heat (argon laser, hot water, drilling).

In order to weld cracks in tooth enamel, it is necessary to bring the surface of the tooth to the fusion temperature of the enamel (greater than 1,000 degrees C). The study investigated whether this increase in surface temperature can cause damage to the vitality of the tooth by recording, using a thermocouple, the temperature in the pulp chamber of teeth exposed to argon laser irradiation (power density after focusing: 4000 W/cm2; duration of continuous irradiation: 1-5 seconds). These pulp temperature increases were compared with those considered safe for the tooth, i.e., contact with a hot drink, drilling of cavities with air + water cooling. It was shown that punctual irradiations with an argon laser for periods of 2 or 4 seconds generated temperature increases in the pulp chamber which were less than inferior to those caused by contact with water at 54-55 degrees C for 1 or 2 seconds, and were of the same order as those caused by the drilling of class III or V cavities of 1 mm in depth and 1 mm in diameter. These results suggest that it is worth continuing research into applying the technique in the mouth.

Body Temperature↗
PubMed1988

Effects of magnetic fields from underwater electrical cutting on in vitro corrosion of dental amalgam.

Metallic taste has been reported from divers working with underwater electric welding and cutting. An in vitro model was designed to simulate the intraoral situation of the divers with respect to the magnetic field. Potentiostatic analyses were performed on amalgam samples exposed to AC and DC magnetic fields. Morphologic changes were analyzed using differential interference light microscopy and scanning electron microscopy. Chemical changes on the surface of the amalgam samples were analyzed with secondary ion mass spectrometry. Results demonstrated that dental amalgams exposed to a specific AC magnetic field underwent morphologic and chemical changes in the superficial amalgam layers.

Corrosion↗
PubMed1987

Oral changes in divers working with electrical welding/cutting underwater.

Divers performing electrical welding/cutting underwater often complain about a metallic taste in the mouth, strictly related to their work. In a nationwide clinical investigation, professional commercial divers were examined orally. The majority of the divers complained about a metallic taste. An increased surface deterioration of dental amalgam was detected in those divers who had performed electrical welding/cutting during the previous two years. In addition, after clinical and bacteriological examination, divers were found to belong to a caries risk group. In order to study the intraoral electrical activity, several actual dives were performed. When they were welding or cutting, the electrical activity registered intraorally in dental amalgam test samples was too low in magnitude to explain the metallic taste and the clinical appearance of the amalgam. The divers were dressed in a dry-suit and full-face mask. When leakage occurred or when a hot-water heated suit was used higher electrical activity was registered. This activity was still not of a magnitude, which could explain the symptoms theoretically, although a metallic taste and a subjective change in the divers dental amalgam were provoked. No increased levels of Hg and Cu could be detected in saliva, blood or urine. The flux density of the intraoral magnetic field created by a current of 650 ADC was calculated and measured to be 1.15 mT, which is approximately 25 times stronger than that of the earth. When exposing divers in-vivo to a field generated by a 200 ADC current, no symptoms other than magnetophosphenes were reported, such as metallic taste. The divers helmets offered almost no shielding effect towards the magnetic field. In-vitro exposure of dental amalgams to a magnetic field (1.15 mT; 50 Hz) increased the mobility of cupper and especially mercurity in the superficial layers of the amalgam after 24 h exposure, and gave rise to slight morphological changes within the amalgam.

Adult↗
PubMed1979

Influence on vision of extremely low frequence electromagnetic fields. Industrial measurements, magnetophosphene studies volunteers and intraretinal studies in animals.

The strong electric currents used for heating purposes in welding and steel industries set up related magnetic fields (generally 0.1--10 mT and 50 Hz). Such fields 10--50 Hz, 0--40 mT) were used to induce visual light phenomena, magnetophosphenes. Threshold values for magnetophosphenes were determined as a function of magnetic field frequency as well as colour and intensity of the background illumination. A typical sensitivity maximum was found at 20--25 Hz. Differences between volunteers with normal colour vision and colour defective ones were observed. The frog retina was exposed to the same type of fields. Retinal activity, induced by the fields, was registered from the ganglion cell layer by means of microelectrode technique. The results indicate that magnetophosphenes are generated in the retina and in the same channels that are normally propagating signals induced by light of different qualities. The findings may be of guidance when formulating threshold limit values for extremely low frequency electromagnetic fields in industry.

Animals↗
PubMed1984

[Chronic renal dysfunction in workers exposed to cadmium oxide fume. Medical examinations of welders using cadmium containing silver solder].

Workers, who had been exposed to cadmium oxide fume, i.e., engaged in welding work with cadmium containing silver solder in an automobile parts manufacturing factory, were examined in 1975. Twenty two male welders were 22 to 55 years old and exposed to cadmium for periods ranging from 7 months to 23 years. Excreted urinary cadmium levels varied from 5.7 micrograms to 184.9 micrograms per day, and these values were useful indices of most recent exposures in workshop environments. The examinees were divided into three groups according to excreted urinary cadmium levels: five of them in high, eleven in middle, and six in low group, respectively. Workers in high-excretion group complained of considerable subjective symptoms and their urinary protein showed a remarkable increase, compared to middle- and low-excretion groups, and the electrophoretic pattern of urinary proteins showed preponderance of globulins. Urinary calcium and beta 2-microglobulin in the high-excretion group showed a remarkable increase. In all examinees, urinary phosphate, calcium, and beta 2-microglobulin were significantly correlated with urinary excreted cadmium. Furthermore, in the high-excretion group showed a considerable increase of serum creatinine values and reduction of creatinine clearance, and percent tubular reabsorption of phosphate, calcium and beta 2-microglobulin decreased. In all examinees, creatinine clearance and percent tubular reabsorption of both phosphate and calcium were significantly negatively correlated with urinary cadmium excretion. Therefore, five high-excretion workers showed evidence of chronic renal tubular dysfunction and one of these was particularly recognized as having remarkable renal damage. The possibility to affirm the effects of exposure to cadmium was suggested on hematological findings related to anemia. Liver function abnormalities were not recognized. A slight reduction of the respiratory function was found in one worker of the high-excretion group, but radiological examination of chest showed no abnormalities in all examinees.

Adult↗
PubMed1983

[Epidemiological studies on the occurrence of lung diseases in welders].

A cross sectional study in electric arc welders revealed significant higher prevalences of simple chronic bronchitis and of nodular opacities in thorax x-rays in spite of exposure below MAC in most cases. Spirometry, flow-volume-curves and bronchial challenges with acetylcholine showed no substantial functional deterioration in comparison with controls. But there are weak dose-response-relations between symptoms as well as lung function data on the one hand and duration of exposure as well as welding fume concentration on the other hand.

Bronchitis↗
PubMed1983

[Endoscopy findings in gastroduodenal pathology in a group of welders].

Fourteen welders were examined with the purpose to evaluate the incidence and the type of pathologic changes of the gastrointestinal tract due to the exposure to welding fumes. The medical examination was followed by endoscopic and bioptic study of gastric and duodenal mucosa. The results show the presence of pathologic changes, mainly of flogistic type, in all the microscopic investigations, although the appearance of the mucosa was generally normal. Moreover, the results of this investigation suggest that pathologic changes of gastrointestinal tract could precede those of the respiratory tract.

Adolescent↗
PubMed1981

[Delayed asthma on diphenylmethane diisocyanate (MDI). The importance of a professional history. The utility and danger of the inhalation tests. Apropos five cases].

While asthma on toluene diisocyanate (TDI) is well known, asthma on diphenylmethane diisocyanate (MDI) has been less frequently described. Following publication of a case in 1972 another is described which was observed in a similar situation (welding of polyurethane belts) and for which the diagnosis remained obscure for some time. A questionnaire sent to factories using this type of belt revealed two other cases of asthma on MDI. A fifth case is described in which provocative testing induced severe cardiovascular disturbances within a few hours after inhalation. Following a short review of the literature, the four new cases mentioned above are presented together with spirometric studies (provocative testing) and immunological investigations.

Aged↗
PubMed1978

[Possibility of the effect of a long-term activity as a welder on the development of a chronic obstructive airway syndrome].

On 62 welders and in a control group consisting of 90 test persons dynamic functional parameters of the lungs were established. In these cases welders older than 40 years after an activity lasting at least 2 decades gave references to a chronic obstructive disease of the respiratory tract, which after exclusion of other etiological factors may be regarded as a sequel of irritatively and toxically effecting welding fumes and gases.

Adult↗
PubMed1995

Comparison of lung radiography and counting of exposure time to magnetopneumography for estimation of total lung dust retention in arc welders.

Magnetopneumography (MPG) is a non-invasive technique to measure the amount of magnetizable dust retained in the lung. This study concerns the relation between MPG measurements of welding fume dust retention in the human lung on the one hand and chest radiography and crude counting of exposure time on the other. Precision and accuracy of the MPG instrument was found to be high. A weak but statistically significant correlation (r = 0.45, P < 0.05) was found between exposure time and retention of magnetizable material in a group of 112 full time manual metal arc welders. The variability was high. Retention rate was estimated on a group level. Chest radiographs of 23 arc welders were reviewed separately in random order by two independent readers who were not aware of MPG findings, occupational anamnesis or the subject's identity and age. No statistically significant correlation was found between MPG and the observer's grading. A weak but statistically significant correlation was found between the readers. We conclude that MPG is highly sensitive to retention of magnetizable material retained in the lung and that the correlation between radiography and MPG reported by previous workers could not be verified in this study. The divergent results may well be due to methodological differences. Investigations using more specific roentgenological methods, such as high resolution computed tomography (HRCT), should be performed.

Adult↗
PubMed1994

[A case of interstitial pneumonitis caused by inhalation of cadmium fumes].

A 48-year-old man who had been a welder for 25 years was admitted to our hospital on February 18, 1990 for investigation of a diffuse bilateral lung shadow that had a ground-glass appearance. On the day of admission, he had been welding copper water supply pipe and used silver brazing with an oxyacetylene torch. After almost 7 hours of work, he had a chill, high fever, and dyspnea. Blood gas analysis revealed severe hypoxemia (PaO2 34.5 Torr, PaCO2 29.4 Torr). The level of copper in serum was slightly higher than normal (174 micrograms/dl). A transbronchial lung biopsy specimen showed lymphocyte infiltration and fibrous changes of the alveolar walls, which seemed to be granulomatous pneumonitis. Steroid therapy was effective against the symptoms, and the radiographic findings also improved. We think this is a rare case of interstitial pneumonitis caused by inhalation of cadmium fumes contained in silver brazing.

Administration, Inhalation↗