Electric Welders Research Articles

Health risk factors among electric and gas welders using different types of welding

Introduction. Preserving the health of the working population is a priority of state policy. The welding process, which is used in many areas of industry, refers to technological processes with harmful working conditions. Monitoring of the production environment, which determines the extent to which the worker is exposed to harmful factors and helps to establish the connection of a particular disease with production activities, is particularly relevant. The aim of the study is to carry out a hygienic assessment of the air in the working area through the conducted studies, to identify risk factors for the health of welders, considering the peculiarities of forming air environment in various types of welding and the technological process organization. Materials and methods . Hygienic studies were carried out on the basis of two large enterprises of mechanical engineering and shipbuilding in Saint Petersburg and on more than 30 separate welding sites of enterprises in the North-West region in 2010-2018. Results. It is established that working conditions during traditional types of welding are determined by the organization of the welder’s workplace and the type of welding. The most unfavorable conditions for the formation of the air environment are characterized by welding of large-sized metal structures, welding in isolated spaces and metal cutting, where existing technical solutions for the installation of localized exhaust ventilation systems are not effective enough. Concentrations of manganese reach 1.6-2.9 mg / m 3 , carbon monoxide-32-61 mg/m 3 , nitrogen dioxide-0.8-1.6 mg/m 3 . An underestimated factor in the welder’s work is the stripping operation that accompanies most welding processes. The dust content reaches 15 mg/m 3 . The occupational health risk of employees was assessed based on the indicators of morbidity with temporary disability, depending on their age and work experience. Conclusions. The implementation of advanced ventilation technologies, improvement of welding equipment, welding methods and materials, expansion of the use of laser welding, and introduction of effective personal protective equipment will help to minimize the risk factors for the health of welders while ensuring the safety of the air environment.

HEALTH INDICATORS IN CERTAIN OCCUPATIONAL GROUPS OF WORKERS

Introduction. Occupational health enforcement in workers as a part of corporate social programs remains an urgent challenge for business entities. Public benefits and economic efficiency of programs for health preservation/disease prevention depend on whether they are arranged well enough with regard to the health status of individual workers and occupational groups. Meanwhile, the regulation of personal data protection limits the ability of business entities to access information about the health status of their employees. Material and methods. We analyzed the physicians’ statements obtained in regular medical examinations of industrial workers for a 5-year period. Results. We identified occupational groups/units with the highest percentage of workers who need sanatorium-resort treatment (SRT). Electric gas welders and furnace operators were estimated to need SRT the most, twice as frequently vs the rest of the workers. Conclusion. Medical check-up examinations not only provide information about the workers with a high risk of occupational diseases, but they also allow identifying occupational groups with a high risk of temporary disability due to common non-communicable diseases. Information obtained from these statements can be used for indicative health assessment in occupational groups of workers. This may be used in detecting prior groups of individuals when planning health-promoting activities and other measures.

Индикаторы здоровья в отдельных профессионально-производственных группах

Introduction. Occupational health enforcement in workers as a part of corporate social programs remains an urgent challenge for business entities. Public benefits and economic efficiency of programs for health preservation/disease prevention depend on whether they are arranged well enough with regard to the health status of individual workers and occupational groups. Meanwhile, the regulation of personal data protection limits the ability of business entities to access information about the health status of their employees. Material and methods. We analyzed the physicians’ statements obtained in regular medical examinations of industrial workers for a 5-year period. Results. We identified occupational groups/units with the highest percentage of workers who need sanatorium-resort treatment (SRT). Electric gas welders and furnace operators were estimated to need SRT the most, twice as frequently vs the rest of the workers. Conclusion. Medical check-up examinations not only provide information about the workers with a high risk of occupational diseases, but they also allow identifying occupational groups with a high risk of temporary disability due to common non-communicable diseases. Information obtained from these statements can be used for indicative health assessment in occupational groups of workers. This may be used in detecting prior groups of individuals when planning health-promoting activities and other measures.

Incidence and yrend of occupational pneumoconiosis in Ankang city from 1974 to 2017

Objective: To understand the epidemiological feature and prevalent trend of pneumoconiosis in Ankang City, pertinently put forward the prevention and control strategy, and provide the basis for comprehensive prevention and treatment of pneumoconiosis. Methods: China Information System for Disease Control and Prevention has exported the network report data of "occupational diseases and occupational health information monitoring" from January 1, 2006 to December 312017 and has created the database; has investigated and supplemented the occupational disease reporting results from January 1, 1974 to December 31, 2005; has conducted the data cleansing through SPSS17.00; has conducted the statistical description and analysis according to pneumoconiosis diagnosis time, age, sex, length of service, industry, and etc. Results: From 1974 to 2017, Ankang City has accumulatively reported 1047 cases of various occupational pneumoconiosis; of which, 992 new cases and 55 stage development cases. Entities of pneumoconiosis include silicosis, coal workers pneumoconiosis, electric arc welders pneumoconiosis, cement pneumoconiosis and asbestosis; number of new cases of silicosis ranks first, the second is coal workers pneumoconiosis. Average length of employment of the occurrence of pneumoconiosis is (15.01±8.95) years; average length of age of the occurrence is (47.11±7.86) years. Distribution of pneumoconiosis involves 8 industries; the first is mining industry (54.23%) , the second is construction industry (27.52%) , and the third is public management, social security and social organization (12.70%) . Pneumoconiosis involves 24 types of work; the first is drillman (47.28%) , the second is main coal miners (15.52%) , and the third is blasters (13.31%) . Conclusion: Prevention and treatment of pneumoconiosis in Ankang City gives priority to silicosis and coal workers pneumoconiosis, puts emphasis on strengthening the prevention of pneumoconiosis of drillman in the mining industry; the occurrence of pneumoconiosis is in a linear upward trend from 2012.

УСЛОВИЯ ТРУДА И ПРОФЕССИОНАЛЬНЫЕ РИСКИ В СТРОИТЕЛЬНЫХ ОРГАНИЗАЦИЯХ ИРКУТСКОЙ ОБЛАСТИ

Construction belongs to a range of production processes characterized with high risks for direct executors of working operations. Its share of industrial incidents is up to 35 %. The development of occupational diseases is caused by unfavourable labour conditions of builders, mobile character of builder’s work, absence of permanent work place, movement of working places and construction materials, combining a complex of similar professions, working in various climate zones and outdoors, irregular working hours. The register of construction organizations of the Irkutsk Region comprises 6,745 big and medium construction organizations of various forms of incorporation, which deal with both industrial and civil construction. The object of study were organisations included in TOP 10 as per the scope of commissioned residential buildings. The source data for assessment of professional risks were the results of special assessment of labour conditions of the studied organisations, as well as data of annual reports on occupational injuries and occupational diseases The calculations revealed that the risk of getting an injury in the construction sector of the Irkutsk Region is comparable to the level of builders’ getting injuries across Russia, and is quite high; the risk of getting an injury in Russia and in the Irkutsk Region within a year equals 0.022 and 0.016 respectively, and during the years of service (25 years) the risk of getting an injury in Russia equals 0.055, and in the Irkutsk Region equals 0.041. It is shown that medium-risk professions include masons, electric and gas welders, carpenters and concrete workers, at all the enterprises under study; the highest specific risk as calculated per one square meter of a constructed residential building was registered for OJSC ISK Vysota.

RISK FACTORS FOR HEALTH DISORDERS IN COPPER-NICKEL MINERS IN THE KOLA POLAR REGION

It is known that copper-nickel miners constitute a group of workers with an increased risk of common and occupational diseases due to the influence of a complex of harmful factors of the working environment and working process The purpose of the study was to investigate the effect of working conditions and duration of work on the formation of health disorders in 1151 miners, engaged in production of copper-nickel ore in the Kola Polar region. It was found that the workers engaged in tunneling and blasting are at the highest risk of developing health problems, particularly diseases of the musculoskeletal system (36.0 % of all cases). The number of diseases diagnosed in one worker of different occupations ranges from (3.22 ± 0.32) cases (in sinkers) to (2.29 ± 0.28) cases (in electric welders). An important risk factor for health problems among miners of all professions is the length of seniority. Compared to the initial period of labor activity (up to 5 years), the prevalence of all health disorders per 100 workers increased by 1.50, 2.09, 2.70 and 3.47 times for the seniority of 6-10 years, 11-15 years, 16-20 years and more than 20 years, respectively. A direct correlation was established between the duration of the employee's experience and the number of his health disorders (r = +0.486). The conclusion is made about the need to prevent health disorders, especially diseases of the musculoskeletal system, from the very beginning of the miners professional career.

Pulmonary Embolism in a Young Adult: A Case Report

SESSION TITLE: Pulmonary Vascular Disease SESSION TYPE: Case Report Poster PRESENTED ON: Sunday, April 17, 2016 at 11:45 AM - 12:45 PM INTRODUCTION: We report the case of a young male adult with PE secondary to deep venous thrombosis that developed during his work as a long-haul truck driver. He was successfully treated with aggressive anticoagulation and antiplatelet treatment. CASE PRESENTATION: A 27-year-old male long-haul truck driver was admitted to our hospital after a 4-day history of severe chest pain and a 1-day history of sputum contained some blood and swollen left lower extremity. Ambulatory pulmonary computed tomography showed a patchy shadow in the lingula of the left lung, and the edges of both lower lobes showed decreased sharpness. Routine blood test results showed a white blood cell level of 13.17 × 109/L, neutrophil percentage of 72.0%, D-dimer level of 1.11 μg/mL, and fibrinogen level of 5.00 g/L. Color Doppler ultrasound of the veins of both lower extremities demonstrated acute-phase thrombosis in the left common femoral vein, superficial femoral vein, and popliteal vein and lymphedema in the left lower leg. Considering all of these findings, we could not exclude the possibility of acute PE. Computed tomography angiography revealed an intraluminal filling defect low-density transect in the basal segment of the left and right lower pulmonary artery branches and transects low density in the lumen of the left upper lobe pulmonary artery branch, which established the diagnosis. Because his condition was classified as low-risk PE. Anticoagulant therapy was administered. The patient’s chest pain was resolved after 5 days, and the anticoagulant therapy was continued. DISCUSSION: PE treatment and diagnosis are frequently delayed because of the complex and nonspecific clinical manifestations[1]. Only 30% of patients are diagnosed to PE who accepted to normal test[2]. Young patients have little basic disease, making it more difficult to diagnose PE, so prevention of PE should be paid more attention. The main risk factors for PE are external injuries, bone fractures, and thrombosis in the veins of the lower extremities. Research indicates that 70% to 90% of thrombi in patients with acute PE originate in the peritoneal cavity, pelvic cavity, and deep veins [3]. Thus, we could reduce the incidence of PE if we remove the risk factors. For young patients, external injuries and bone fractures have been evaluated, but vocational factors have been largely overlooked, such as long-haul truck drivers, electric welders, office workers, pipeline fabricators, therfore those in similar professions should exercise their lower extremities often and take regular physical examination. CONCLUSIONS: It is very important to identify vocational risk factors associated with the development of PE, especially in young adults. Reference #1: Konstantinides, SV. Acute pulmonary embolism revisited: thromboembolic venous disease. Heart. 2008;94:795-802. Reference #2: Blann, AD, and Lip, GY. Venous thromboembolism. BMJ. 2006;332:215-219. Reference #3: Somarouthu, B, Abbara, S, and Kalva, SP. Diagnosing deep vein thrombosis. Postgrad Med. 2010;122:66-73. DISCLOSURE: The following authors have nothing to disclose: Ying Liu, Lianlian Zhang, Luyao Sun, Qianqian Yu, Zhenxiang Yu No Product/Research Disclosure Information

Occupational Risk And Health Status Of Workers In The Production Of Heat

Summary The health status of 1515 workers employed in heat production was investigated. The subjects studied were divided in four groups according to occupation and occupational risk factors: vibration, noise, dust, metal aerosols, overloading of the musculoskeletal and peripheral nervous system, and organic solvents. The control group included 152 administrative staff members. High prevalence of socially significant diseases – cardiovascular, endocrine and metabolic was detected in all the groups surveyed. The frequency of diseases of the cardiovascular system and the respiratory system was 2.7 times higher than that in the control group. Statistically reliable higher prevalence of lung diseases in the studied risk groups was found, especially in the group of welders and chemists: 45.3% и 17.4% respectively, as compared to 4.3% in the controls. These finding corresponded to the occupational risk. The following occupation diseases were diagnosed: pneumoconiosis in 26.6% and toxic pneumofibrosis in 5.1% of electric welders. As regards the group of chemists, toxic pneumofibrosis was found in 6.5%. toxic effects of irritants - in 6.5 %, and chronic intoxication with organic radicals - in 0.7 % of them. Occupational auditory neuritis was diagnosed in 1% of the turbine operators and crane operators. The relative share of workers with peripheral nervous system pathology (radiculopathies, polyneuropathies, distal sympathetic neuropathy, mononeuropathy) was reliably higher than that in the control group, and the frequency increased among the workers with more than ten years of service and older than 40.

Health related quality of life and influencing factors among welders.

BackgroundOccupational exposure to welding fumes is a serious occupational health problem all over the world. Welders are exposed to many occupational hazards; these hazards might cause some occupational diseases. The aim of the study was to assess the health related quality of life (HRQL) of electric welders in Shanghai China and explore influencing factors to HRQL of welders.Methods301 male welders (without pneumoconiosis) and 305 non-dust male workers in Shanghai were enrolled in this study. Short Form-36 (SF-36) health survey questionnaires were applied in this cross-sectional study. Socio-demographic, working and health factors were also collected. Multiple stepwise regress analysis was used to identify significant factors related to the eight dimension scores.ResultsSix dimensions including role-physical (RP), bodily pain (BP), general health (GH), validity (VT), social function (SF), and mental health (MH) were significantly worse in welders compared to non-dust workers. Multiple stepwise regress analysis results show that native place, monthly income, quantity of children, drinking, sleep time, welding type, use of personal protective equipment (PPE), great events in life, and some symptoms including dizziness, discomfort of cervical vertebra, low back pain, cough and insomnia may be influencing factors for HRQL of welders. Among these factors, only sleep time and the use of PPE were salutary.ConclusionsSome dimensions of HRQL of these welders have been affected. Enterprises which employ welders should take measures to protect the health of these people and improve their HRQL.

Welding of Attachments in Orthodontics: Technique Recommendations based on a Literature Search

Joining of fixed appliance components has several applications in orthodontics. Joining attachments to archwires allows the clinician to transfer the point of force application to a location that is more advantageous from a biomechanical standpoint. Although several methods of joining attachments have been proposed, resistance spot welding and soldering have been the most commonly used procedures. Despite its common use, the literature regarding spot welding has been scarce and the technique improperly applied. The aim of this article is to describe the theory behind the use of electric spot welders and achieving an optimum weld joint. Recommendations have been made for the correct application of the parameters involved in electric resistance spot welding so that a clinically useful weld joint can be obtained.

Effect of health education intervention on the awareness and use of personal protective equipments among small scale electric arc welders in Ilorin, Nigeria.

Introduction:Welding is associated with workplace hazards that can affect the health of those who engaged in it as they are exposed to harmful dust.Subjects and Methods:This was a health education intervention study carried out among self-employed electric arc welder. Data were collected using an interviewer administered questionnaire and health education intervention was carried out between the preintervention and postintervention stages. Epi-info version 3.5.1 software package was used for data analysis and Chi-square analysis was used to determine the statistical significance of observed differences between the study and control groups before the intervention and after intervention. Level of significance was set at a P < 0.05.Results:At the preintervention phase, 285 respondents were interviewed in each of the study and control groups, while 280 study respondents and 275 control respondents were available for the postintervention phase of the study. Before the intervention, 279 (97.9%) of the respondents in the study group were aware of eye goggles as a means of protection, 20 (7%) were aware of welding helmet, 206 (72.3%) were aware of hand gloves and 4 (1.4%) were aware of face mask. All showed a significant increase in awareness postintervention (P < 0.05) while there was no significant increase in awareness in the control group.Conclusion:Health education brought about a significant increase in awareness and use of personal protective equipment among the welders. There is a need for proper education of welders on workplace hazards, the types and use of different protective devices in other to safeguard their health.

Pattern of Ocular Injuries and Use of Protective Eye Devices among Welders

The aim of this study was to determine the pattern of ocular injury amongst welders in Egor Local Government Area of Edo State, Nigeria. A crosssectional study was conducted between February and June 2007, with the aid of pre-tested questionnaires. Ocular examination was performed on all subjects. A total of 271 welders comprising 220 electric welders (81.2%) and 51 gas welders (18.8%) were seen. All subjects were males. Their ages ranged from 12 to 61 years with a mean age of 27 years + 8.49 (SD). Among the 104 welders (38.4%) who had a history of work related ocular injury, the gas welder was more likely to have a history of work-related injury 2 compared to the electric welder (x 2 = 13.339, df=1, p-0.000). Superficial foreign body (78.8%) was the commonest type of injury. The agents causing injury were metal chips, welder's arc ray and sand. A total of 234 welders (86.3%) used protective eye wear while 37 (13.7%) did not use. Welders should be educated on the regular use of protective eye devices in order to prevent ocular injury.

Association between polymorphism of dopamine β-hydroxylase and neurological dysfunction hereditary susceptibility of electric welders

To investigate the relationship between genetic polymorphism of dopamine β-hydroxylase (DBH) and manganese-induced nerve injury. In a cross-sectional study, 402 electric welders who had worked over one year in relatively fixed sites were recruited, and the concentration of manganese in which they worked was stable. These samples was divided into high exposure group (CEI > 1) and low exposure group (CEI < 1) by CEI. Between the two groups, the groups were divided into abnormal group and normal group according to the result of neurologic check (there were 81 workers with abnormal neurological dysfunction in high exposure group and 28 workers in low exposure group, P < 0.05). Polymorphism of DBH gene was analyzed with polymerase chain reaction-restriction fragment length polymorphism. The distribution of A2A2 genotype and A2 allele of DBH was significantly different. In high exposure group, the distribution of A2A2 genotype and A2 allele of DBH in abnormal group was significantly wider than in normal group (A2A2 genotype, OR = 1.248, P < 0.05, A2 allele, OR = 1.103, P < 0.05). In low exposure group, the distribution of A2 allele of DBH in abnormal group was significantly wider than in normal group (OR = 1.176, P < 0.05). The individuals who carry A2A2 genotype and A2 allele of DBH have increased risk of neurological dysfunction after explosion to manganese for a certain time, which suggests that polymorphism of DBH (intron 5 Taq I) would play a great role in hereditary susceptibility of neurological dysfunction cause by manganese.

Epidemiological investigation of welder's pneumoconiosis in two container manufacturing industries in Guangdong province

To investigate the incidence of welder's pneumoconiosis in container manufacturing industries in Guangdong province and present some preventive and curative strategy. Occupational epidemiology study methods were used to study the incidence of welder's pneumoconiosis in two container manufacturing enterprises (enterprise A and enterprise B). Before 2004, the rate of up-to-standard of weld fume concentration in the workplaces was relatively low (< or = 40%), and the maximum value of time weighted average (TWA) was 26.7 mg/m(3). After 2004, with the system of dust control, the rate of up-to-standard was 85% in the enterprise A. Of the 813 weld workers examined, 19 were diagnosed as welder's pneumoconiosis (stage I was 15, while I (+) was 4 ) and the incidence was 2.34% (19/813). The age of electric welders suffering from welder's pneumoconiosis and the duration of dust exposure were (33.45 + 4.64) and (8.04 + 1.97) years respectively. Chest radiographic examination showed mainly small round opacities "p". The value of MVV, FEF25%, FEF50% and FEF75% in lung function tests were significantly lower than those of the control group (P < 0.05 or P < 0.01). The main features of welder's pneumoconiosis in container manufacturing industries are the short duration of dust exposure, and small round opacities "p" in the chest radiographs. Therefore, it should be the key point of the prevention and treatment of occupational diseases in this industry to control the harmful weld fume.

Aerosols of low cytotoxic metal oxide condensates as an etiological factor of occupational cardiomyopathy

Smelters working with aluminum and brass-bronze alloys and electric welders working with carbide and low-alloyed steel develop primary myocardial injury independent on hypertension and coronary atherosclerosis. This injury is characterized by structural disorders such as myocardial concentric and eccentric hypertrophy, concentric remodeling left heart myocardium, non-coronarogenic pain, changes of T-wave in ECG, and cardiac arrhythmias. According to the 10th International classification of diseases, such signs should be considered as cardiomyopathy caused by environmental exposure, namely by fine-particle aerosols of condensates of zinc, aluminum and iron oxides having slow solubility and cytotoxity.

The Health of Electric Arc Welders and the Adoption of Arc Welding in the British Shipbuilding Industry, 1930–1951

The Health of Electric Arc Welders and the Adoption of Arc Welding in the British Shipbuilding Industry, 1930–1951

Ultraviolet radiation and human health

The sun is responsible for the development and continued existence of life on Earth. We are warmed by the sun’s infrared rays, and we can see with eyes that respond to the visible part of the sun’s spectrum. More importantly, visible light is essential for photosynthesis, the process whereby plants, necessary for our nutrition, derive their energy. Besides serving as the ultimate source of food and energy for humans, sunlight also acts on them to alter their chemical composition, control the rate of their maturation, and drive their biological rhythms; however the ultraviolet component, which comprises approximately 5% of terrestrial solar ultraviolet (UV) radiation, is largely responsible for the deleterious effects associated with sun exposure. Prior to the beginning of this century, the sun was our only source of exposure to UV radiation; but with the advent of artificial sources, the opportunity for additional exposure has increased. Exposure may be elective (eg sunbathing, cosmetic tanning with sunbeds, or medical therapy), or adventitious, often as a consequence of occupation (eg electric arc welders). Both the quality (spectrum) and quantity (intensity) of terrestrial ultraviolet radiation varies with the elevation of the sun above the horizon, or solar altitude. The solar altitude depends on the time of day, day of year, and geographical location. On a summer’s day, WB (290-320 nm) comprises approximately 5% of terrestrial ultraviolet, and WA (320-400 run) the remaining 95%. But since WB is much more effective than WA at causing biological damage, solar WB contributes about 80% towards the harmful effects we associate with sun exposure, with solar WA contributing the remaining 20%. The quality and quantity of solar UV are modified on its passage through the atmosphere. The principal interactions in the stratosphere (-10 to 50 km above sea level) are absorption by ozone and scattering by molecules such as nitrogen (NJ and oxygen (0,). In the troposphere (0 to -10 km above sea level), absorption by pollutants such as ozone, nitrogen dioxide (NO,)

Epidemiological studies on occupational eye pathology.

We examined 522 persons exposed to different types of non-ionizing radiation (UV, IR lasers) in the working environment. The control group consisted of 250 persons. The clinico-statistical analysis of occupational eye pathology depending on etiological factors, exposure time and age is presented. Specific cataracts were found in 38.37% of electric welders and in 11.4% of metal workers. The number of cataracts increased with exposure time and in elderly workers. We also observed six macular incidents when working with lasers. The results show the potential hazardous factors of the working environment and the corresponding eye impairments.

Comparision of Chest Radiographs and Pulmonary Function in Coal Workers' Pneumoconiosis and Welders' Lung

Background: Chest X-ray of coal workers' pneumoconiosis and shipyard welders' lung show similar and regular opacities mostly, it is very difficult that we distinguish the former from the latter by only chest X-ray. so we performed this study to understand the progression of the disease and to provide the disease by considering pulmonary function and other factors in proportion to the profusion of small regular opacities of chest X-ray in both groups. Method: 430 coal workers' pneumoconiosis were compared with 311 shipyard welders' lung by the number, the age, the duration of dust exposure, %vital capacity(%VC), %FEV1.0, the type of ventilatory impairment, the combined pulmonary disease according to the profusion of small regular opacities on the chest radiographs, which were classified into category 0/1, category 1, and category 2. Result: 1) the percent of category 2 in coal workers' pneumoconiosis was 54.4%. the percent of category 1, and category 2 in welders' lung were 60.0%, 7.4%. the progression to the category 2 was higher in coal workers' pneumoconiosis than in welders' lung 2) The mean age was higher in coal workers' pneumoconiosis than in welders' lung, significantly increased in proportion to the progresion of profusion of small regular opacities in both groups 3) There was no difference in the duration of dust exposure by category 1/0, but the duration of dust exposure by category 1, 2 in coal workers' pneumoconiosis more significantly increased than in welders' lung. the duration in the proportion of category 2 to category 0/1, 1 significantly increased in the proportion to small regular opacities in coal workers' pneumoconiosis. but there was no significant difference in the proportion to small regular opacities in duration of dust exposure in welders' lung. 4) There was no significant difference of mean values of %VC(%vital capacity)in both groups except for category 1. the mean values of %VC had no relationship between the progression of small regular opacities in both groups. 5) The mean values of %FEV1.0 decreased more significantly in coal workers' pneumoconiosis than in welders' lung except for category 0/1. and decreased significantly in proportion to the profusion of small regular opacities in coal workers' pneumoconiosis. there was significant difference of %FEV1.0 in the proportion of category 2 to category 011 in welders' lung. 6) there were no significant difference of %FEV1.0, %VC in smoker and nonsmoker in both groups. 7) With regard to the type of ventilation in both groups in coal workers' pneumoconiosis 21.4 percent of patients belonged to the restrictive type, 11.6 percent to the obstructive type, 5.6 percent to the combined type, but in welders' lung 21.8 percent to the restrictive type, 2.9 percent to the obstructive type, 1.9 percent to the combined type. 8. in the pulmonary disease, the incidence of the pulmonary tuberculosis was the most in both groups, was more in coal workers' pneumoconiosis than welders' lung Conclusion: If we compare coal workers' pneumoconiosis with electric arc welders'lung by considering pulmonary function and other factors in proportion to the profusion of chest X-ray, I think that we will have the better result in understanding the progression of the disease and provision of the disease in both groups.

Identification of the magnetic fields generated by welding machines

Welding-process devices are one of the major sources of strong magnetic fields. The circuits' currents can reach values of many kiloamperes. Taking into account the fact that the work place of the welding-machine operator is located a small distance from the circuit of the high current and that the operating worker is under the influence of strong magnetic fields, one has to assume that electric welders may be a real danger to the health of the workers. Using the theory of vector potential, the magnetic fields generated by a typical configuration of electrodes were calculated. To experimentally verify the proposed procedure of calculation, the magnetic fields near a typical welding machine were measured. All measurements were made with the aid of an H-meter equipped with a coil flux probe. Statistical verification of the theoretical calculation and measurements for all components and total magnetic fields are presented.