1、EFFECTS OF WELDING ON EALTH IV Effects of Welding on Health IV An up-dated (December 1980- June 1982) literature survey and evaluation of the data recorded since the publication of the first report, to understand and improve the occupational health of welding personnel. BY Winifred G. Palmer Submitt
2、ed by: Tracor Jitco 1776 E. Jefferson Street Rockville, MD 20852 Submitted to: SAFETY AND HEALTH COMMITTEE 550 N.W. LeJeune Road Miami, FL 33126 AMERICAN WELDING SOCIETY International Standard Book Number: 0-87 171-230-X American Welding Society, 550 LeJeune Road, Miami, FL 33126 01983 by American W
3、elding 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 (Tracor Jitco) which is solely responsible for its contents. The materials in this reporthave not been independently reviewed or verified
4、 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 of America I AWS EWH-4 83
5、 0784265 000508L - 7 W . f/ * I? . / Contents Personnel v Acknoruledgements vii Preface . i Introduction . xi Executive Summary . xi11 Technical Summary . xv . 1 . The Exposure i 1.1 Fumes . 1 1.2 Gases 5 1.3 Protective Coatings 7 1.4 Electromagnetic Radiation 9 1.5Noise . 10 2 . Effects of Welding
6、on Human Health 11 2.1 Respiratory Tract 11 2.2 Cancer 15 2.3 Effects on the Ear and Hearing . 19 2.4 Effects on the Eye and Vision 19 2SEffectsontheSkin . 20 2.6 Effects on the Cardiovascular System . 21 2.7 Effects on the Nervous System . 21 2.8 Effects on the Liver . 22 2.9 Effects on the Musculo
7、skeletal System 22 2.10 Effects on the Urogenital Tract 23 2.1 1 Effects on the Teeth and Oral Cavity 23 2.12 Metal Fume Fever . 23 2.13 Sensitivity to Fume Components 23 2.14 Biochemical Changes 24 2.15 Human Fatality . 25 2.16 Occupational Medicine . 25 3 . Toxicologic Investigations in Animals an
8、d in Cell Cultures 25 3.1 Animai Studies 25 3.2 In Vitro Studies 29 References 31 Bibliography 37 iii Personnel The author of the report by Tracor Jitco was: Winifred G. Palmer AWS Research Committee A.N. Ward, Chairman K. L. Brown, Vice Chairman M. E. Kennebeck, Jr., Secretary Caterpillar Tractor C
9、ompany Lincoln Electric Company American Welding Society J.S. Gorski Kemper Insurance Companies E. Mastromatteo INCO Limited 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 pr
10、ogram by industry contributions. Supporting Organizations Air Products and Chemicals, Inc. Airco Welding Products Allis-Chalmers Alloy Rods Division, The Chemetron Corporation AWS Detroit Section AWS New OrIeans Section Arcos Corporation The Binkley Company Caterpillar Tractor Company Chicago Bridge
11、 and Iron Company Grove Manufacturing Company, Division of Kidde, Inc. General Electric Company The Heil Company Hobart Brothers Company Huntington Alloys, Inc. Lincoln Electric Company Miller Electric Manufacturing Company National-Standard Company A.O. Smith Corporation Teledyne-McKay, Inc. Trinit
12、y Industries, Inc. Truck Trailer Manufacturers Association Walker Stainless Equipment Company Weld Tooling Corporation Many other organizations have made contributions to support the ongoing program from May 1979 to the present. AWS EWH-4 83 0784265 0005083 O vi i - /,- k,. / ;j Preface This literat
13、ure 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 welding on health, as well as to aid in the formulation of research projects in this area, as part of an ongoing program sponsored by the S
14、ociety. Previous work has included studies of the fumes, gases, radiation, and noise generated during various forms of arc welding (see Bibliography). Conclusions based on this review and rec- comendations for further research are presented in the introductory portions of the report. Section 1 summa
15、rizes recent studies of the occupational exposures. Section 2 contains information related to the human health effects of exposure to byproducts of welding operations. Section 3 discusses studies of the effects of welding emissions on laboratory animals and in vitro cell systems. Referenced materias
16、 are available from Tracor Jitco, Inc. Introduction The health of workers in the welding environment is a major concern of the American Welding Society. To stay abreast of this subject, the health literature is periodically reviewed and published in the report Effects of Welding on Health. Three vol
17、umes have been published to date (Refs. 135, 143, and 144); the first covered data published prior to 1978, while the latter two covered the periods 1978 to May, 1979 and June, 1979 to December 1980, respectively. The current report included information that was pub- lished between December, 1980 an
18、d June, 1982, and should be read in conjunction with the previous volumes for a comprehensive treatment of the litera- ture on the Effects of Welding on Health. Included in this volume are studies of the charac- teristics of welding emissions that may have impact on the control technologies necessar
19、y to protect the welding worker (Section i), Considerable discussion is devoted to ozone which may become a greater problem to welders as improved ventilation and decreased fume exposures reduce the rate of degenera- tion of this hazardous gas. Much recent research has focused on chromium and nickel
20、, since exposure to certain chemical forms of these metals may cause serious chronic health problems. In keeping with previous volumes, the health studies are organized according to the organ system affected. The respiratory tract, the primary route of entry of welding fumes and gases into the body,
21、 also is a major target organ of a number of components of these emissions. Acute (e.g., metal fume fever, cadmium poisoning) as well as potential chronic respiratory effects (e.g., emphysema, cancer) of welding emissions are of concern. The latter are far less well understood and whether or not the
22、re is an excess risk of cancer from these exposures has not been established. Con- tinued research in the form of epidemiologic studies, investigations with laboratory animals, and in vitro genotoxicity studies will help to resolve this question. Executive Summary A problem inherent in research conc
23、erning the health effects of welding is that there is a great deal of variability in both welding processes and in working conditions which makes it difficult to perform studies on homogeneous populations of sufficient size to permit statistical analysis. These variations may be less critical when e
24、xamining causes of acute physiological responses to welding exposures (e.g., metal fume fever, burns, photokeratitis). However, the association between chronic exposures to welding emissions and disease conditions whose causes are less well under- stood, or which occur at a low incidence, remains am
25、biguous in many cases. The Respiratory Tract Of the five metals (Cr, Ni, As, Be, and Cd) that have been shown by epidemiologic studies to be related to an increased cancer incidence in workers in certain industries, chromium and nickel are present in signifi- cant quantities in fumes released during
26、 welding certain metals (e.g., stainless steel and nickel alloys). However, only some chemical compounds containing these metals are carcinogenic, and it is not known if these compounds are present in welding fumes. The available epidemiologic evidence is insufficient to determine whether or not wel
27、ders are at an increased risk of developing lung cancer from exposure to chromium and nickel in welding fumes. Most of the reports of the effects of welding on health which appeared during the period of this review dealt with effects of welding on the respiratory tract. Metal deposits have frequentl
28、y been found in welders lungs by chest X-rays and at autopsy. The use of magnetopneumography enables rough estimates to be made of the quantities of metals retained in the lungs, However, the association between this retention of metals and impaired lung function is not clear. For this reason, it is
29、 important to develop more accurate methods for the determination of lung function. Of the six studies using pulmonary function tests of welders which appeared during this report period, three indicated impaired lung function among welders, and three reported no differences between welders and contr
30、ols. Four epidemiologic studies of the lung cancer incidence among welders have appeared in the recent literature. Two of these indicated an elevated lung cancer risk. One of these two studies focused on welders of stainless steel, but the size of the study cohort was too small for the results to be
31、 considered conclusive. The second was a death record study of welders selected from the rosters of a trade union in Seattle, Washington. A significant increase (SMR*=174) in the lung cancer rate was found when deaths that occurred more than 20 years from the initial date of exposure were considered
32、. A study of welders exposed to nickel-rich welding fumes did not indicate an elevated lung cancer risk; however, the investigator emphasized the need for a follow-up study of this cohort to allow more time for the appearance of tumors. There is a great need for further well- planned epidemiologic s
33、tudies of welders. Because of the high cost of these studies and the limited resources available to the welding community, Stern suggested *Standardized mortality ratio xiii AWS EWH-4 83 M 07842b5 0005087 8 that such studies focus on exposure to welding processes in which it is suspected that genoto
34、xic or carcinogenic materials, such as nickel and chromium compounds, are released (Ref. 122). Other Organ Systems Reports of recent health studies that examined the effects of welding on organ systems other than the respiratory tract are highlighted below. - With the exception of cutaneous burns an
35、d erythema of the neck which were more common in welders, no significant differences between the fre- quency of skin and eye disorders were found between welders and nonwelders from the same fabrication facility. Good safety and health measures were prac- ticed in this plant. - An excess of inflamma
36、tion of the oral mucous membranes, including periodontal disease, was observed in two separate studies of welders. - No differences were observed in the morphology, number, and motility of sperm produced by welders and by workers in other occupational groups. Biological Monitoring of Exposure to Wel
37、ding Emissions The development of methods for the accurate determination of personal exposures are needed to establish and measure the effectiveness of control xiv technologies. In conjunction with devices that collect personal air samples for determining the welders actual exposure, biological moni
38、toring affords a means for estimating the actual dose of contaminants taken up by the body. Such tests are useful for the support of population and epidemiologic studies and for the evaluation of the effectiveness of industrial hygiene measures introduced to reduce worker exposure. Finally, biologic
39、al monitoring during routine medical examinations may play an important part in alerting the occupational physician to indivi- duals who may be exposed to unacceptable levels of welding emissions. The importance of this area of research is witnessed by the number of studies that have been published
40、on this subject. Studies using magnetopneumography have demonstrated that the amount of materials retained in the lung correlates with the number of years spent welding, the extent of siderosis, and the relative quantity of fumes generated by the welding process. In other work, the relationship betw
41、een urine concentrations and breathing zone levels was linear for fluorine, suggesting that this element may be useful for monitoring the exposure of welders who use basic- coated electrodes. Although urine chromium levels tended to increase during the work week, this metal nevertheless may be usefu
42、l for estimating exposures to fumes generated by welding of stainless steel, Urine nickel levels tend to fluctuate widely and are apparently not a useful measure of nickel exposures. Technical Summary of sample collection, storage, and extraction pro- cedures may affect the analytical results (Refs.
43、 11,49, and 128). Gases The of toxic gases, e,g., nitrogen oxides, ozone, and carbon monoxide, during welding are discussed. Johansson (Ref, reported that the addition of helium or hydrogen to shield gases reduced the ozone levels released during GMAW or GTAW of stainless steel, and Smars (Ref. 117)
44、 reported that the addition of nitric oxide, but not helium, significantly reduced ozone levels during GTAW of aluminum. Fumes The major objectives of research on fume emissions are to evaluate health hazards, to develop welding methods which produce less toxic fumes, and to enable estimation of air
45、 exchange rates required to bring fume concentrations to acceptable levels. Total fume emissions are greatest with shielded metal arc welding and flux cored arc welding and vary with the electrode used and welding parameters. To determine the airflow requirements of ventilation systems, Alekseeva et
46、 al. examined the emissions released during gas tungsten arc welding of manganese- _,_ /D -4 containing from 2 to 70% nickel (Ref. 5). Pokhodnya et al. (Ref, 102) found that the rate of manganese vaporization from rutile or basic electrodes increased with the alkalinity of the slag. Oleinchenko et a
47、l. (Ref. 98) determined that fluoride emissions from electrode coatings increased with the moisture of the coating during automatic aluminum welding. A large portion of the solid phase of welding aerosols consists of respirable particles. Particles may exist as single entities or as chains or agglom
48、erates (Refs. 12,23,51,70 and 81). When present, chromates appear to be condensed on the surface of metal oxide particles (Refs, 70 and 81). Two major interlaboratory studies are currently examining methods for the determination of soluble and insoluble hexavalent chromium in welding emissions (Refs
49、. 11 and 51). Variations in the methods oxide in shield gases may be a greater hazard than the ozone whose formation it prevents. The presence of magnesium, but not silicon, in aluminum alloys significantly reduces the production of ozone during GMAW of aluminum (Ref. 117). Prod uc t ion Coat i ng s Primers or paints on metal surfaces may contribute significant quantities of formaldehyde, carbon monoxide, hydrogen cyanide, and other organic vapors to welding emissions (Ref. 21). These vary primarily with the characteristics of the binders used in the coatings. Electromagnetic Rad
