9 1 K o r e a n In d. H y g. A s s oc. J V o l. 9, N o. 1. M a y, 1 9 9 9, * * Abs tract Airborne Concentrations of W elding F ume and Metals of Workers Expos ed to Welding F ume Ho Chun Choi, Kangyoon Kim, Sun Hee An, Wha Me Park, So Jin Kim, Young Ja Lee*, Kyou Chull Chang Institute of Occupational Health, Korean Industrial Health Association, Seoul, Korea Departm ent of Industrial Safety, Seoul H ealth College, Sungnam, K orea* Airborne concentrations of welding fumes in which 13 different metals such as Al, Cd, Cr, Cu, Fe, Mn, Mo, Ni, Pb, Si, Sn, T i, and Zn were analyzed were measured at 18 factories including automobile assembly and manufactures, steel heavy industries and shipyards. Air samples were collected by personal sampler at each worker' s worksite(n=339). Blood levels of Cd, Cu, Fe, Mn, Pb and Zn were also measured from samples taken from 447 welders by atomic absorption spectrometry and compared with control values obtained from 127 non exposed workers. T he results were as follows ; 1. Among various welding types, CO2 welding 70.2 % were widely used, shielded metal arc welding(smaw) 22.1 % came next, and rest of them were metal inert gas(mig) welding, submerged arc welding(saw), spot welding(spot ) and tungsten inert gas(t IG) welding. * 1997. 56
2. Welding fume concentration was 0.92 / (0.02 15.33 / ) at automobile assembly and manufactures, 4.10 / (0.02 70.75 / ) at steel heavy industries and 5.59 / (0.30 91.16 / ) at shipyards, respectively, showing significant difference among industry types. Workers exposed to high concentration of welding fumes above Korean Permissible Exposure Limit(KPEL) amounted to 7.9 % and 12.5 % in CO2 welding and in SMAW at automobile assembly and manufactures and 62.7 % in CO2 welding, and 12.5 % in SMAW at shipyards, and 66.2 % in CO2 welding and 70.6 % in SMAW at steel heavy industries. 3. Geometric mean of airborne concentration of each metal released from welding fumes was below one 10th of KPEL in all welding types. Percentage of workers, however, exposed to airborne concentration of metals above KPEL amounted to 16.8 % in Mn and 7.6 % in Fe in CO2 welding; 37.5 % in Cu in SAW, 30 % in Cu in T IG; and 25 % in Pb in SPOT welding. As a whole, 76 workers(22.4 %) were exposed to high concentration of any of the metals above KPEL. 4. T here were differences in airborne concentration of metals such as Al, Cd, Cr, Cu, Fe, Mn, Mo, Ni, Pb, Si, Sn, T i and Zn by industry types. T hese concentrations were higher in shipyards and steel heavy industries than in automobile assembly and manufactures. Workers exposed to higher concentration of Pb above KPEL amounted to 7.4 % of workers(7/94) in automobile assembly and manufactures. In shipyards, 19.2 % of workers(19/99) were over exposed to Mn and 7.1 %(7/99) to Fe above KPEL. In steel heavy industries, 14.4 %(21/146), 7.5 %(11/146) and 13 %(19/146) were over exposed to Mn, Fe and Cu, respectively. As a whole, 76 out of 339 workers(22.4 %) were exposed to any of the metals above KPEL. 5. Blood levels of Cd, Cu, Fe, Mn, Pb, and Zn in welders were 0.11 /100, 0.84 /, 424.4 /, 1.26 /100, 5.01 /100 and 5.68 /, respectively, in contrast to 0.09 /100, 0.70 /, 477.2 /, 0.73 /100, 3.14 /100 and 6.15 / in non exposed control groups, showing significantly higher values in welders but Fe and Zn..,,. (Shielded Metal Arc Welding), (Metal Active Gas Welding, MAG, CO2 ), (Metal Inert Gas Arc Welding, MIG), (Submerged Arc Welding), (T ungsten Inert Gas Arc Welding), (Plasma Arc Welding),.,,, (Spot),,,,,,,.. 60 %, 30 % 10 % 57
(, 1997). 5500.,,., (Fe), (Mn), (Cu), (Cr), (Ni), (Zn), (, 1984). CO2,. (C) 2 % (Fe C). (Al),, (Co), (Cr Ni), (Cr Al),,, (Si), (W),,..,, (Siderosis) (Benign Pneumoconiosis),.. Bavaria (Radiographic findings) (Stokinger, 1981).,., (Shielded Metal Arc Welding), CO2 (Metal Active Gas Welding, ), (Submerged Arc Welding), (T ungsten Inert Gas Arc Welding) (Spot)., (Cd),, (Cu),,, (Mo),, (Pb),, (Sn), (T i) 13,,,,, 6. II. 1. 1997 7 1998 4,,,. 18 339 7 (94 ), 2 (99 ), 9 (146 ), 5 447 58
3 (373 ), 1 (35 ), 2 (39 ) 127.,,,,,,,,,,,, 13,,,,,, 6.. 2. 1) cellulose ester membrane (Millipore Corp., U.S.A., 37, 0.8 pore size) 3 piece cassette (MSA, Gillian, U.S.A.) 2 /min 240 452.,. 20. 2) ) 24, 0.01 (AE 240, Mettler, Switzerland),.. (Spectr AA 30, Varian, Australia).,, acetylene air, N2O acetylene air,,,,,,,, (Shimadzu AA 6701, Japan; Hitachi Z 8100, Japan),. T able 1,. (LOD; Limit of detection) /sample, 500 1.6 102 /, 1.1 106 /, 2.4 105 /, 2.6 106 /, 4.3 103 /, 1.5 103 /, 2.8 105 /, 3.3 106 /, 2.5 105 /, 2.0 105 /, 8.4 105 /, 1.0 104 /, 6.5 104 /. ) (matrix modifier) T riton X 100. D2 (SpectrAA 30, Varian, Australia),,,,, Zeeman (Z 8100, Hitachi, Japan),. T able 1 0.17 /100, 0.0005 /, 0.11 /100, 0.072 /100,, 0.0325 /, 0.0044 /. 3) statistical analysis system(sas, version 6.12), 59
Table 1. Analytical conditions of metals in airborne welding fume and blood samples Elem ents Parameters Al Cd Cr Cu Fe Mn Mo Ni Pb Si Sn T i Zn W av eleng th( ) 309.3 228.8 357.9 324.8 248.3 279.5 313.3 232.0 283.3 251.6 224.6 364.3 213.9 1. M etal in w elding fum e T em p. pr ogram ( ) Dry 120 250 120 250 120 250 120 250 120 250 80 120 80 120 80 120 A s hing 300 700 500 900 800 550 650 900 A tom izing 1500 2500 2500 2700 2500 2000 2700 3000 LOD ( / ) 1.6 102 1.1 106 2.4 105 2.6 105 4.3 103 1.5 103 2.8 105 3.3 106 2.5 105 2.0 105 8.4 105 1.0 104 6.5 104 2. M etal in blood T em p. pr ogram ( ) Dr y 70 120 80 120 60 140 80 120 A s hing 300 600 600 500 900 700 A tom izin g 1700 2700 2500 2300 LOD 0.017 / 100 0.0005 / 0.0325 / 0.11 /100 0.072 / 100 0.0044 / LOD: Limit of detection (shapiro wilk test) (geometric me an, GM) (geometric standard deviation, GSD)., (ANOVA).. 1. 18 < T able 2>.,. CO2 (Shielded Metal Arc Welding, SMAW), (Submerged Arc Welding, SAW), (T ungsten Inert Gas Arc Welding, T IG). CO2 (0.09 0.57 %) (0.02 1.50 %), (19.80 24.00 %), (9.50 13.00 %). CO2,, (0.40 0.75 %), (0.65 1.45 %), (0.00 2.28 %) (0.00 1.04 %). 2. CO2,,,, (MIG),, ( ). < T able 3> < Fig. 1> CO2 339 238 70.2 %, 75 22.1 % 92.3 % 60
Table 2. Metal components by welding rods Welding rod Base metal N Metal components, weight % Mn Si Cr Ni Mo MAG SMAW SMAW T IG MAG SMAW T IG MS MS SS SS MA MA MA 6 5 2 3 3 6 2 1.05 1.50 0.02 1.10 1.30 1.33 0.98 1.96 0.65 0.86 0.67 1.20 0.75 1.45 0.41 0.55 0.09 0.57 0.54 0.68 0.38 0.48 0.40 0.58 0.48 0.53 0.41 0.75 23.70 24.00 19.80 19.96 1.05 2.21 2.26 1.32 0.00 2.28 12.00 13.00 9.50 9.95 0.00 2.70 0.53 1.04 0.13 0.55 0.00 1.00 MAG: Metal active gas welding, CO2 welding SMAW: Shielded metal arc welding T IG: Tungsten inert gas welding MS: Mild steel, SS: Stainless steel, MA: Metal alloy Table 3. Airborne concentrations of fume by welding types Welding types MAG SMAW SAW SPOT T IG N(%) 238( 70.2) 75( 22.1) 8( 2.4) 8( 2.4) 10( 2.9) Concentrations of welding fume GM( / ) GSD Range( / ) 3.84 2.09 1.36 0.15 2.23 4.41 4.17 2.22 3.56 2.97 0.02 91.17 0.02 61.53 0.62 5.75 0.02 0.55 0.59 33.16 No. of exceeded KPEL (%) 106(44.5) 17(22.7) 1(12.5) 0(. ) 1(10.0) T otal 339(100.0) 2.99 4.66 0.02 91.17 125(36.9) F value 12.33*** *** P< 0.001 MAG: Metal active gas welding, CO2 welding T IG: Tungsten inert gas welding SPOT : Spot welding, a kind of pressure welding KPEL: Korea permissible exposure limits SMAW: Shielded metal arc welding SAW: Submerged arc welding. CO2 3.84 / (0.02 91.17 / ), 2.09 / (0.02 61.53 / ), 1.36 / (0.62 5.75 / ), 0.15 / (0.02 0.55 / ), 2.23 / (0.59 33.16 / ) (p< 0.001). CO2 5 / CO2 44.5 %, 22.7 %, 12.5 %, 10.0 %, 339 125 36.9 %. 0.02 91.17 /. 3. 61
Fig. 1. Airborne concentrations of fume by welding types, 90 % CO2.,,,,,. 0.92 / (0.02 15.33 / ), 4.10 / (0.02 70.75 / ), 5.59 / (0.30 91.16 / ) < T able 4>. CO2 (p< 0.001). 94 8 8.5 %, 146 63 43.2 %, 99 54 54.5 %, 339 125 (36.9 %). 4. 13, 1/10. (0.0001 / ), (0.0002 0.0008 / ), (0.0001 0.0013 / ) (0.0002 0.0005 / ). Fig. 2. CO2,,,,,,, (p< 0.001),, (p<0.01), (p<0.05). < T able 5>. CO2 238 40 16.8 %, 18 62
7.6 %, (37.5 %) (30.0 %).
Fig. 2. Airborne concentration of metals by welding types. (* P<0.05, ** P<0.01, *** P<0.001) Table 5. Samples of exceeded Korean permissible exposure limit of metals by welding types Welding types N No. of exceeded Korean permissible exposure limit*(%) Al Cd Cr Cu Fe Mn Mo Ni Pb Si Sn T i Zn T otal(%) MAG 238 11(4.6) 18(7.6) 40(16.8) 1(0.4) 4(1.7) 1(0.4) 61(25.6) SMAW 75 1(1.3) 4(5.3) 1(1.3) 6( 8.0) SAW 8 3(37.5) 3(37.5) SPOT 8 2(25.0) 2(25.0) T IG 10 1(10.0) 3(30.0) 1(10.0) 4(40.0) T otal 339 2(0.6) 21(6.2) 18(5.3) 40(11.8) 2(0.6) 7(2.1) 1(0.3) 76(22.4) * Korean permissible exposure limits( / ): Al(5.0), Cd(0.05), Cr(0.5), Cu(0.1), Fe(5.0), Mn(1.0), Mo(10.0), Ni(1.0), Pb(0.05), Si(10.0), Sn(2.0), T i(10.0), Zn(5.0) 64
Fig. 3. Airborne concentration of metals by industry types(* P 0.01). Table 6. Samples of exceeded Korean permissible exposure limit of metals by industry types Industry types Automobile assembly & manufacturing Steel structure manufacturing N No. of exceeded Korean permissible exposure limit(%) Al Cd Cr Cu Fe Mn Mo Ni Pb Si Sn T i Zn T otal(%) 94 1(1.1) 7(7.4) 8(8.5) 146 2(1.4) 19(13.0) 11(7.5) 21(14.4) 2(1.4) 49(33.6) Shipyards 99 1(1.0) 7(7.1) 19(19.2) 1(1.0) 19(19.2) Total 339 1(0.3) 15(4.9) 18(5.8) 40(13.0) 1(0.3) 5(1.6) 1(0.3) 76(22.4) * Korea permissible exposure limits( / ): Al(5.0), Cd(0.05), Cr(0.5), Cu(0.1), Fe(5.0), Mn(1.0), Mo(10.0), Ni(1.0), Pb(0.05), Si(10.0), Sn(2.0), T i(10.0), Zn(5.0) 2 /100 46 (12.3 %), 7 (17.9 %), 10 (28.6 %) 63 (14.1 %). 40 /100 3 (0.8 %). 1 /100 28 (22.0 %), 2 /100 2 (1.6 %), 40 /100. 65
Table 7. Concentration of blood metals of controls and welding workers by industry types Groups Industry types N Concentration of metals in blood Cd( /100 ) Cu( / ) Fe( / ) Mn( /100 ) Pb( /100 ) Zn( / ) Automobile assembly & manufacturing 373 0.11(1.75) LOD 0.48 0.84(1.16) 0.41 1.39 426.7(1.22) 166.4 630.4 1.24(1.56) 0.28 5.26 5.09(1.57) 1.50 92.20 5.77(1.24) 2.52 11.20 Exposure Steel heavy industry 39 Shipyard 35 0.10(1.85) LOD 0.38 0.17(2.27) 0.03 0.56 0.80(1.11) 0.69 1.06 0.85(1.11) 0.59 1.01 389.3(1.2) 282.8 524.2 441.0(1.1) 377.6 531.4 1.11(1.72) 0.31 2.97 1.70(1.45) 0.83 4.33 5.02(1.41) 2.90 16.30 4.26(1.31) 2.21 8.20 5.92(1.19) 4.06 10.86 4.62(1.12) 3.36 5.80 Subtotal 447 0.11(1.82) LOD 0.56 0.83(1.15) 0.41 1.39 424.4(1.2) 166.4 630.4 1.26(1.58) 0.28 5.26 5.01(1.54) 1.50 92.20 5.68(1.24) 2.52 11.20 Control 127 0.09(1.78) 0.03 0.37 0.70(1.12) 0.44 1.21 477.2(1.1) 298.4 648.0 0.73(1.59) LOD 2.14 3.14(1.42) 1.50 8.51 6.15(1.17) 4.28 9.16 ANOVA table of among industry types ANOVA table of between exposure and control group 9.16*** 1.94 4.96** 9.51*** 2.69 19.69*** 16.85*** 138.15*** 43.79*** 142.11*** 124.15*** 15.29*** ** P< 0.01, *** P< 0.001 LOD: less than limit of detection Table 8. No. of exceeded 1.0 /100 MnB, 2.0 /100 MnB and 40 /100 PbB Groups Industry types N No. of exceeded limits 1.0 / 100 1) MnB4)(%) 2.0 /100 2) MnB(%) 40 /100 3) PbB(%) Exposure Automobile assembly & manufacturing 373 272(72.9) 46(12.3) 3(0.8) Steel heavy industry 39 23(59.0) 7(17.9) Shipyard 35 33(94.3) 10(28.6) Sub total 447 328(73.4) 63(14.1) 3(0.7) Control 127 28(22.0) 2( 1.6) 1) 1.0 /100 MnB: reference value by Lauwerys & Hoet(1993) 2) 2.0 /100 MnB: WHO(1986) 3) 40.0 /100 PbB: BEI by Ministry of Labor in Korea(1994) 4) MnB: manganese in blood.,.,,,,,, 66
.,.,,,. (National Institute for Occupational Safety and Health, NIOSH),,, 6.., (Siderosis),,,. 40 % (Wallace etal, 1997).,,, (, 1989),,, (NO2), (O3) (asbestos), (chromium, Cr), (nickel, Ni), (cadmium, Cd), (lead, Pb), (aluminum, Al), (iron oxide, Fe2O3) (Rom, 1992). (T LV=5 / ) Fe2O3 Fe3O4 (siderosis), ferrosilicon silicon dioxide. 3, 6,,, (Matczak Chmielnicka, 1993),,, (Kilburn etal. 1990). Fairfax(1994) 0.32 0.73 /, 11.3 /. S tokin g er (1981) 2.1 nmol/mmol creatinine 0.7 nmol/mmol creatinine,..,,, (, 1994;, 1997; Karlsen, 1994).,,,,, (Shielded Metal Arc Welding), CO2 (Metal Active Gas Welding, ), (Submerged Arc Welding), (T ungsten Inert Gas Arc Welding),,. (Spot).,,., NIOSH,,,,,,,,,,. (Shielded Metal Arc Welding, SMAW),, CO2, 67
(T ungsten Inert Gas Arc Welding, T IG) < T able 3>., 9.50 24.00 %. 1.05 2.28 % 0.13 1.04 %. (1991) 50 44 (88.0 %) 5 / 9.73 / (2.14 24.86 / ) 2.99 / (0.02 91.17 / ), (1998) 0.88 1.35 /. (1997) 6 (n=40) 3.0 /, (n=5) 7.8 /, (n=44) 13.2 /, (n=58) 15.1 /. 40 % (1991), (1997) < T able 4, p< 0.001>.,,,,,,,,,,,,, < Fig. 2>. 1/10. (1997) (25.5 %), (4.5 %), (3.6 %), CO2 28.2 %, 9.1 %, 7.8 %,,. CO2, CO2 40,. CO2 18,. CO2. CO2,,,,,. CO2 CO2.,. < Fig. 3>.,,,,,,.,,,,,,,,,,,,.,,,,., < T able 6>.,... 68
(Roels etal 1987; Elias etal, 1989; Kilburn etal, 1990;, 1994).,,,,,,, < T able 7> (p< 0.001).,,,, (P< 0.01, p< 0.001).. 40 /100 3 (0.8 %) (1.1 2.7 ),.. 3.,. Stok in ger (1981),.,.. (5.68 /, n=447) (6.15 /, n=127). 6.48 1.04 / (n=145) (, 1986)...., 2.. 1:1 4:1. (Stokinger, 1981)., 2. WHO(1986) 2 /100, Lauwerys Hoet(1993) 1 /100. (1994), Roels etal.(1987), Elias etal(1989), Kilburn etal.(1990), Symth etal.(1973). (1998) (r=0.3183), (cumulative exposure index, ) (r=0.3542). (American Conference for Industrial Hygie ne Association, ACGIH, 1997). 1.0 / 339 40 (11.8 %), 2 /100 14.1 %, 10.0 /100 (, 1994). 10.0 /100, 69
..., 18 339,,,,,,,,,,,, 13, (n=447),,,,, (n=127). 1. CO2 3.84 /, 2.09 /, 1.36 /, 0.15 /, 2.23 /,. CO2 44.5 %, 22.7 %, 12.5 %, 10 %, 339 125 36.9 %. 0.02 / 91.17 /. 2. 0.92 / (0.02 15.33 / ), 4.10 / (0.02 70.75 / ), 5.59 / (0.30 91.16 / ). 8.5 %, 43.2 %, 54.5 %. 3. 1/10. CO2 16.8 %, 7.6 %, 37.5 %, 30 %, 25 %, 22.4 %(76 ). 4.,,,,,,,,,,,,. 94 7 (7.4 %), 99 19 (19.2 %), 7 (7.1 %), 146 21 (14.4 %), 11 (7.5 %), 19 (13 %). 339 76 22.4 %. 5. 0.11 /100, 0.09 /100, 0.83 /, 0.70 /, 424.4 /, 477.2 /, 1.26 /100, 0.73 /100, 5.01 /100, 3.14 /100, 5.68 /, 6.15 /. 6. 1 /100 72.9 %, 59.0 %, 94.3 %, 2 /100 12.3 %, 17.9 %, 28.6 %. 40 /100 0.8 %. REFERENCES, :. 1991; 1(1): 68 72.,,, :. 1994; 6(1): 98 112. 70
:,,, 1984, 1 25., :. 95 3 6.,, 1994.,, :. 1996; 8(3): 383 391.,,,,,,, :. 1997; 7(2): 181 195. :,, 1984; 1 25., :. 1994; 4(1): 71 80., :. 1998; 31(1): 104 111.,, :,. 1989; 22(4): 486 494.,,, :. 1998; 10(4): 534 547. :. 97 4 13,, 1997. ACGIH : 1997 T LVs and B E Is. 1997. Bennett PA, Rothery E : Introducing A tomic A bsorption A nalysis. Mulgrave, Varian Publication. 1983; 74. Bergman I, Casswell C. Lung dust and lung iron contents of coal workers in different coal fields in Great Britain. Brit J Ind Med 1972; 29: 160 168. Elias Z, Mur JM, Pierre F, Gilgenkrantz S, Schneider O, Baruthio F, Danière MC, Fontana JM : Chromosome aberrations in peripheral blood lymphocytes of welders and characterization of their exposure by biological samples analysis. J Occup Med. 1989; 31(5): 477 483. Fairfax RE : Manganese exposure during welding operations. Am Ind Hyg Assoc J 1994; 9(8): 537 538. Freedman RW, Sharkey AG : Recent advances in the analysis of respirable coal dust for free silica, trace elaments, and organic constituents. Ann NY Accad Sci 1972; 200: 7 16. Hewitt PJ, Madden MG : Welding process parameters and hexavalent chromium in MIG fume. Ann Occup Hyg. 1986; 30(4): 427 434. Jahr J, John BK : N ickel E xposure and E excretion during W elding of Stainless Steel. International Institute of Welding, Document No. 587 74. London, 1974; 327 331. Karlsen JT, T orgrimsen T, Langard S : Exposure to solid aerosols during regular MMA welding and grinding operations on stainless steel. Am Ind Hyg Assoc J 1994; 55(12): 1149 1153. Kilburn KH, Warshaw R, Boylen CT, T hornton SM, Hopfer SM, Sunderman FW, Finklea J : Cross shift and chronic effects of stainless steel welding related to internal dosimetry of chromium and nickel. Am J Ind Med. 1990; 17(5): 607 615. Lauwerys RR, Hoet P : Industrial Chem ical E xposure Guidelines for B iological M onitoring 2nd E d. 1993, Lewis Publishers. Matczak W, Chmielnicka J : Relation between various chromium compounds and some other elements in fumes from manual metal arc stainless steel welding. Brit J Ind Med. 1993; 50(3): 244 251. Roels H, Lauwerys R, Genet P, Sarhan MJ, Hanotiau I, Buchet JP : Relationship between external and internal parameters of exposure to manganese in workers from a manganese oxide and salt producing plant. Am J Ind Med 1987; 11: 297 305. 71
Sawatari K, Serita F : Determination of chromium speciation in fumes prepared by a plasma metal sprayer as a model of actual welding fumes. Ind Health. 1986; 24(1): 51 61. Slavin T J : W elding Operations. In In plant P ractices for J ob R elated H ealth H az ards Control volume 2 Engineering A spects. by Cralley LV and Cralley LJ. NY, John wiley & sons, 1989. 507 540. Stokinger HE : T he Metals. In Patty' s Industrial Hygiene and T oxicology. Vol 2A. Clayton GD & Clayton FE. JNY, ohn Wiley & Sons, 1981, 1494. Wal JF : Further studies on the exposure of welders to fumes, chromium, nickel and gases in Dutch industries: Plasma welding and cutting of stainless steel. Ann Occup Hyg. 1986; 30(2): 153 161. Wallace ME, Fischbach T, Kovein RJ : Control technology assessment for the welding operations. In depth survey report. NIOSH, 1997. WHO : Disease Caused by Manganese and Its T oxic Compounds. In Early Detection of Occupational Disease. WHO, Geneva, 1986; 69 73. 72