1、I. L I EFFECTS OF WELDING ON HEALTH .Ill L n i Effects of Welding on Health 111 An up-dated (June 1979-December 1980) literature survey and evaluation of the data recordedsince the publication of thefirst report, to understand and improve the occupational health of welding personnel. Research perfor
2、med by the Franklin Institute under contract with the American Welding Society and supported by industry contributions. BY Samir Zakhari and John Strange Franklin Institute Research Laboratory, Inc. A Subsidiary of the Franklin Institute The Benjamin Franklin Parkway Philadelphia, PA 191 O3 Prepared
3、 for: SAFETY AND HEALTH COMMITTEE AMERICAN WELDING SOCIETY P.O. Box 351040 Miami, Florida 33 135 - AWS EWH-3 3 ? 07842b5 0005042 8 ? International Standard Book Number: 0-87171-226-1 Library of Congress Number: 79-52672 American Welding Society, 550 LeJeune Road, Miami, FL 33126 01983 by American We
4、lding Society. All rights reserved. This report is published as a service and convenience to the welding industry and is the product of an independent contractor (Franklin Institute Research Laboratory) which is solely responsible for its contents. The materials in this report have not been independ
5、ently reviewed or verified and are only offered as information. AWS assumes no responsibility for any claims that may arise from the use of this information. Users must make independent investigations to determine the applicability of this information for their purposes. Printed in the United States
6、 of America Contents Personnel., . v Acknowledgements . vii Preface ix Introduction . xi Technical Summary xi11 . 1 . The Exposure . 1 1.1 Fumes 1 1.2 Gases . 4 1.3 Radiation . 4 1.4 Noise . 5 2 . Effects of Welding on Human Health 5 5 2.2 Mutagenicity of Carcinogenicity of the Fumes and Gases . 15
7、2.3 Epidemiologic Studies . 16 2.1 Toxicity to Various Organs . 3 . Toxicologic Investigations in Animals . 16 4 . In Vitro Studies 18 5 . Conclusions and Recommendations . 19 References . 21 . 111 AWS EWH-3 3 W 07842b5 0005044 I W- L_- Personnel Authors of the report by Franklin Research Center wer
8、e: Samir Zakhari and John Strange AWS Research Committee A. N. Ward, Chairman K. L. Brown, Vice Chairman M. E. Kennebeck, Jr., Secretary Caterpillar Tractor Company Lincoln Electric Company American Welding Society J.S. Gorski Kemper Insurance Companies E. Masrromatteo INCO Limited V 07A42b5 0005045
9、 3 W Acknowledgements The American Welding Society gratefully acknowledges the time and effort expended by the members of the Research Committee and the financial support of the program by industry contributions. Supporting Organizations Air Products and Chemicals, Inc. Airco Welding Products Allis-
10、C halmers Alloy Rods Division, The Chemetron Corporation AWS Detroit Section AWS New Orleans Section Arcos Corporation The Binkley Company Caterpillar Tractor Company Chicago Bridge and Iron Company Grove Manufacturing Company, Division of Kidde, Inc. General Electric Company The Heil Company Hobart
11、 Brothers Company Huntington Alloys, Inc. Lincoln Electric Company Miller Electric Manufacturing Company National-Standard Company A.O. Smith Corporation Teledyne-McKay, Inc. Trinity Industries, Inc. Truck Trailer Manufacturers Association Walker Stainless Equipment Company Weld Tooling Corporation
12、Many other organizations have made contributions to support the ongoing program from May 1979 to the present. vii Preface This literature review has been prepared for the Safety and Health Committee of the American Welding Society to provide an assessment of current knowledge of the effects of weldi
13、ng on health, as well as to aid in the formulation of a research program in this area, as part of an ongoing program sponsored by the Committee. Previous work has included studies of fumes and gases, radiation, and noise generated during various forms of arc welding. Conclusions based on this review
14、 and recommendations for further research are presented in Section 5 of the report. Section 1 summarizes the occupational exposures. Sections 2 and 3 contain information related to the effects of exposure to byproducts of welding operations on humans and laboratory animals. Section 4 covers in vitro
15、 studies. Referenced materials are available from the Franklin Institute. ix - AWS EWH-3 83 m 078LiZb5 - 0005047 7 m -_ Introduction The American Welding Society (AWS) has been concerned about the possible health hazards due to the exposure of welders to fumes, gases, radiation, and noise from vario
16、us welding processes. Although much has already been learned about welding processes and technology, the effects of welding on human health have not been fully understood. To help the studying and understanding of the welding environment and its effects on health, the AWS has undertaken a literature
17、 review entitled “Effects of Welding on Health” that was published in 1979, and has been updated to cover the period of January 1978 to May 1979. Since then, interest in studying the effects of the welding environment on the various physiological systems has continued and many articles have ap- pear
18、ed in the published literature. The present effort represents a continuation of assessing the effects of welding on health and presents an update to include information published from June 1979 to December 1980. The reader is cautioned that the papers reviewed were examined only for consistency. No
19、independent checks of the experiments or findings were performed. This report must be read in conjunction with “Effects of Welding on Health” by Villaume et al., and the update by Zakhari and Anderson (Vol II). References are listed at the end in alphabetical order based upon first author. xi AWS EW
20、H-3 83 = 0784265 0005048 7 m _ Technical Summary The objective of this report is to evaluate and pres- ent the state-of-knowledge of the effects of welding on health, to point out gaps in this knowledge, and to provide recommendations to the American Welding Society for future studies. This report c
21、overs the period of June 1979 to December 1980, and must be read in conjunction with the previous literature review (Villaumeet al. 1978) and the updatewhich covers the period January 1978 to May 1979 (Zakhari and And- erson, 1981). This report, as is the case of the previous two reports, is divided
22、 into 4 sections entitled: i) The Exposure, 2) Effects of Welding on Human Health, 3) Toxicologic Investigations in Animals, and 4) In Vitro Studies. The Exposure In this chapter, studies performed on welding fumes, gases, radiation, and noise are summarized. Fumes During welding, particulate matter
23、 is generated from the base metal, welding rod, the flux, any coat- ings or contaminants of the metal surface, or any com- bination of these. The rate of fume generation and the composition and particle size distribution of the fumes vary according to the metal being welded and the welding method us
24、ed. The components that are of special concern to welders include silicon compounds, chromium, nickel, fluoride, copper and manganese. Because of the potential health hazard of hexavalent chromium to man, several efforts have been made either to minimize the amounts of chromium in weld- ing fumes, o
25、r to develop sensitive methods of continu- ously monitoring its concentrations in the ambient atmosphere of welders and in their biological fluids. Potential health hazards from welding fumes are determined not only by the composition of the fumes and their concentration in air, but also by the dura
26、tion of exposure as well as the particle size distribution. Fortunately, these hazards can be overcome by the use of appropriate protective devices and by engine- ering controls. Gases Contrary to the common belief that ozone is found in high concentrations in the vicinity of welding areas, studies
27、conducted by Press (1978) revealed that very low concentrations of ozone are formed during plasma arc cutting. These low concentrations were ascribed to the reaction of ozone with nitrous oxide and the disin- tegration of ozone due to the presence of dust particles. Radiation Welding produces electr
28、omagnetic radiation that can be divided into visible, ultraviolet, and infrared. Radiation of wavelength shorter than 175 nm are rarely encountered during welding due to their absorp- tion by atmospheric oxygen (Lunau, 1967). Theuse of thoriated tungsten welding electrodes (GTAW pro- cess) could res
29、ult in the exposure to thorium and daughters contained in these electrodes. The magni- tude of the radiation to which welders may be exposed was estimated to be between 20 millirem and one rem. xiii AUS EWH-3 83 W 07842b5 0005047 O Noise Dixon (1978 a) found that the noise of an electron beam weldin
30、g machine was directly proportional to the beam voltage and current. Effects of Welding on Human Health In this chapter, the effects of welding on human physiological systems are discussed. Data about carci- nogenicity of welding fumes and gases, and epidemio- logical studies are summarized. Toxicit
31、y to Various Organs Respiratory System Keskinen et al. (1980) reported on two asthmatic patients in whom attacks were precipitated by welding fumes. Examination of the occupational history of these patients revealed previous employment at a cement factory and an iron foundry where cement dust, clay
32、dust, and iron fumes were prevalent. Chronic exposure to gases and particulates in welding atmos- phere could result in interstitial fibrosis of the lungs (Loriot et al. 1979). On the other hand, Gola et al. (1980) found that only 7 persons out of a group of 73 arc welders, exhibited symptoms of chr
33、onic non- specific bronchopulmonary disease. Chronic bronchi- tis was also reported in welders with up to 30 years of exposure to welding fumes (Candarella et al., 1979). Other chronic effects reported included inflammatory changes of the mucosa (Kup, 1979), and pneumoconi- osis (Rabenda, 1980). Lun
34、g function tests have been used to assess the effects of acute and chronic exposure to welding fumes. However, results of the lung function tests were inconsistent and contradictory. For instance, Oxhoj et al. (1979) found that welders showed a significantly higher closing lung volume and capacity t
35、han the con- trols; on the other hand, McMillan and Heath (1979) found that welders showed obstructive lung diseases, whereas controls showed restrictive lung diseases. However, individuals with most abnormal patterns were smokers. The degree of contribution of smoking or welding fume to the conditi
36、on is unknown. Al- though McMillan and Heaths study was well designed and executed, the statistical significance could vary by changing the size of the population. Ross (1978) exam- ined 926 welders and controls for lung function tests and found that, on several occasions, welders had significantly
37、better results than the controls. Radiographic changes in lungs of welders have been very studied by Attfield and Ross (1978) who found few abnormalities until the worker had been employed for 15 years; the prevalence of pneumoconi- osis steadily increased thereafter. Ear and Hearing burns due to sp
38、arks or foreign bodies. Jarzebski (1979) reported on cases of middle ear Eyes and Vision Alkali fumes produced during welding can cause con- siderable eye irritation. Exposure to ultraviolet radia- tion causes very little immediate discomfort on expo- sure but might, in severe cases, cause irreversi
39、ble photochemical reaction in the pigment layer. Perman- ent damage could be caused by thermal effects which might be aggravated by the simultaneous photochemi- cal reaction due to ultraviolet radiation. Lovsund et al. (1979 b) found no evidence of any “a1arming”effect on thevisual system from short
40、 term exposure to magnetic fields generated during welding processes. Effects of welding on readaptation time (RAT, time that elapses from the moment of exposure to a bright light until a certain object reappears) was studied by Linde (1980) who found a marked increase in RAT with fumes from basic e
41、lectrodes but not from rutile electrodes. Welders who wear contact lenses should use other means for adequate safety protection, and a qualified person should be available to remove the lenses in an emergency. Skin Most of skin injuries are caused by flying hot metal particles and exposure to ultrav
42、iolet radiation. Con- tact eczema was reported in unprotected electric welders (Weiler, 1979). An Epidemiological study of 200,000 cases of skin cancer failed to link this condi- tion to welding. Musculoskeletal System An epidemiologic study was conducted by Nau- Wald in 1980 on 100 welders in the s
43、hipbuilding indus- try. Although the sample is too small to allow any significant conclusion, the author claimed that welders are at an increased risk of developing knee joint diseases. Biochemical Effects Heavy metals were found in various biological fluids and tissues of welders in higher concentr
44、ations than the control group. Grund (1980) found high manganese contents of hair samples obtained from shipyard welders; Bernacki et al. (1976) found high nickel concentrations in the urine of arc welders; expo- sure to welding fumes also resulted in a decrease in xiv AWS EWH-3 _ 83 W 07892!0005050
45、 7 W plasma proline, alkaline phosphatase, and lactate dehydrogenase; and an increase in plasma hydroxy- proline (Mlynarczyk and Senczuk, 1980; Wysocki et al, 1980). Mutagenicity and Carcinogenicity Bloom(1979) studied theeffects of ozone on human chromosome response in blood samples taken from 247
46、welding trainees. A slight rise in the percentage of cells with single chromatid and isochromatid gaps was demonstrated after 6 weeks of exposure, but declined by the twelfth week. However, no statistically signifi- cant increases were seen in any category of other chromosome-type abberations studie
47、d. Epidemiologic Studies Beaumont (1980) studied the mortality of welders and other trade workers in the Greater Seattle area. No definitive conclusions could be reached by Beau- mont as to the cause and effect relationship of various diseases in welders; higher incidence of cancer of the respirator
48、y system and pneumonia was found in welders. Since records of these welders showed that they performed various jobs (e.g. in shipyard, metal fabrication, field construction, etc.) in the same year, Beaumonts findings cannot be ascribed to a given occupational exposure. McMillian (1979,1980) conducte
49、d anepidemiologic study on the health of welders in the Royal Dockyards and found no evidence of anexcess of chronic respira- tory diseases. Toxicologic Investigations in Animals Rats were exposed to 1,178 mglm3 of fumes gener- ated by SMAW process using flux coated electrodes for 45.8 minutes. The concentration of iron in the lung tissue was 2,185 ug/g of lung tissue immediately after exposure. This concentration was reduced to 1,085 ug/g 30 hours later, and 657 ug/g 30 days later. The overall elimination rates of iron was less than those of chromium and cobalt. However, t
