Document zQM0Q1J4YDYYeVO3n03Zo7KM3

This Health Hazard Evaluation (HHE) report and any recommendations made herein are for the specific facility evaluated and may not be universally applicable. Any recommendations made are not to be considered as final statements of NIOSH policy or of any agency or individual involved. Additional HHE reports are available at http://www.cdc.gov/niosh/hhe/reports HETA 86-524-1851 NOVEMBER ! 987 FOUR WHEEL DRIVE CORPORATION CLINTONVHLF, WISCONSIN NIOSH INVESTIGATORS: Daniel Almagner, M.S. Thomas Matte, M.D, M.PJH. I. SUMMARY On September 22,1986, the National Institute for Occupational Safety and Health (NIOSH) received a request from the Allied Industrial Workers Union. Local 816 to investigate arptoyee exposures to adding fumes, pant, asbestos and complaints ofrespiratory and other health problems among workets at the Four Wheel Drive (FWD)5eagiave inaniifacturing facility in Clirttcnville, Wisconsin. Based on information collected during a walk-through survey ofthe plant on November 18-19,1986, the NIOSH investigatots determined tlrt a medical and industrial hygiene survey ofwelders and an industrial hygiene survey ofthe asbestos brake slxre machining operation were indicated These surveys were conducted from March 9 to March 12,1987. Personal samples were collected near die breathing zone of33 wekfcts and analyzed gravimetrically for total dust and analyzed by inductively coupled argon plasma-atomic emission spectroscopy for 28 metals. Total airborne welding fumeoonoentratons ranged from 0.7 milligrams per cubic meterofairfmg^T) to 62 mgM\ Two samples exceeded tire Occupational Safety and Health Administration (OSHA) permissible exposure limit (PEL) of 5 mg/M1 and 11 were greater titan 50% ofthe OSHA PEL Nickel concentrations ranged from 0.001 to 0.022 mg/M1; one sample exceeded the NIOSH recommended exposure limit (REL) of0.015 mg/M1 and 4 were greater than 50% ofthe NIOSH REL Silver was detected in 1 sample at a concentration of0.015 mgM1 which exceeds the OSHA PEL ofO.01 mg/M1. Production volume during the survey was tower than usual Airborne asbestos in personal and area samples in foe brake slioe machining area was below the analytical limit of detection Bulk samples ofbrake shoe sliavings contaminating die floor and equipment in that area contained 10 to 20% chiysotile asbestos. A questionnaire and spirometry were administered to 46 weldets and 36 non-welding machine shop employees. Welders had higlier prevalences than controls for 10 out of 12 work-associated symptoms ofirritation ofthe upper and lower respiratory tract, and for two ofthese symptoms (eye imtation and throat irritation) the differences between weldets and controls were statistically significant Among welders who had ever anoked, there was a statistically significant association between longer tenure as a welder at FWD and poorer performance on spirometric measures ofairflow (FEV1 and FEF 25-75) by multiple regression analysis. DEFENDANT'S 3 EXHIBIT HWBUI0007299 Based on these results, the NIOSH invesdgitors concluded that there was a health hazard from exposure to welding fume at the Four Wheel Drive Corporation, and that a potential for significant exposure to asbestos exists in file brake shoe machining area Reamnendatiorts for engineering controls to reduce exposure to welding fame and to asbestos dust arc included in Section IX ofthis repot KEYWORDS: SIC 3711 (Motor Vehicles), welding fame, nickel, silver, asbestos, chromium HWBUI0007300 INTRODUCTION On September 12,1986, The National Institute for Occupational Safety and Health (NIOSH) received a request from The Allied Industrial Workers Union, Local 816 to investigate exposures to welding Himes, paints, asbestos, and complaints ofrespiratory and other health problems among workers at tine Four Wheel Drive (FWDySeagrave manufacturing facility in Qirfcnvie, Wisconsin NIOSH investigators conducted a walk-through survey oftire plant on November 18-19,1986. Based on observations made at that time, the NIOSH investigator made prelininatyrecminiendatais and reviewed these in the interim letter dated December 8,1986. On Maich 9-12,1987, NIOSH conducted an industrial hygiene survey and a medical evaluation ofemployees at Four Wheel Drive Corporation, Qintonville, Wisconsin On April 20, 1987, a letter was 9ent to workers who participated in the medical survey, notifying them oftheir own pulmonary function test results. On July 27,1987, the NIOSH investigators sent an interim letter to the company and union officials summarizing toe results ofthe envkrnraTtal survey. During die initial walk-through visit, sixteen welders were interviewed infonnally. Several ofthese workers reported work-associated symptoms such as cough, sore throat and eye irritation, and nearly all expressed concern over long-term effects ofrepeated exposure to welding fume in areas tlrey considered poorly ventilated. Five full-time spray painters in the paint/body shop wen; aka interviewed Some reported occasional eye irritation when using uretlvane paints. None reported work-associated symptonas suggestive ofexcessive solvent exposure, and all wore supplied-air respirators or halfmask respirators equipped with an organic vapor cartridge while spray painting Copies ofprevious investigations conducted by the US. Efepartment ofLabor, Occupational Safety and Health Administration (OSHA), Appleton Area Office during March 1985 and September 1986 were obtained from toe oonpany and reviewed. During the March 1985 inspection, personal air samples for selected employees in the paint and body shop indicated exposures exceeding tire OS! IA pennissible exposure limit (PEL) forcadmium (spray painter), chromate (two spray painters and one body strop worker), nuisance dust (body shop worker), and lead (body shop worker). Additionally, FWD was cited for deficiencies in their respiratory protection program and medical surveillance program for lead-exposed workers. During the September 1986 OSHA investigation, personal breadling zone air samples collected from four painters indicated exposures in excess ofthe OSHA PEL of 50 micrograms per cubic meter (mcgTvf) for lead Ore body slwp worker was exposed to total nuisance dust in excess ofthe OSHA PEL of 15 milligrams pa cubic meter (nig/M'). Results from semi-annual blood lead monitoring ofworkers with potential lead exposure were retrieved and reviewed These included blood lead tests from 27 employees on December 10,1985, and from 23 employees on July 22,1986. No blood lead level exceeded 20 micrograms HWBUI0007301 per dra]ilff(mc^'dI)CnieOSHA action level is40 mcgdl). An inquiry to the OSHA office which approves laboratories for OSHA - mandated blood lead monitoring revealed, however, that in December 1985, the test lab was not approved, based on perfonnance on quarterly proficiency tests. The lab was .approved in July ! 986. It is this possible that true blood lead, levels may have differed from the reported lesuhs in Etecernber. During the initial walk-through, a potential for hazardous exposure to asbestos during a brake shoe machining operation was observed Hus potential hazard was described and recommendations made regarding its abatement in die interim letters to the company dated December 8,1986 and July 27,1987. Based on infcmiation obtained during the walk-througli visit and other information gathered, it was decided to conduct a medical and industrial hygiene slew/ focusing on welding operations and an industrial hygkme assessment ofdie brake shoe machining operation at the FWD5eagrave manufacturing facility. BACKGROUND A Plant Production and Workforce: FWD Corporation manufactures heavy duty, multiple-axle drive trucks and firetnicks at die FWD/Seagrave facility in Gintonville, Wisconsin Far hundred and thirty-five persons were employed there at the time of ar initial visit, 313 ofthese being union sliop employees. Major processes at the plant include machining of purchased forged and cast metal parts, cutting and stamping ofsheet metal, welding ofvarious frame and body assemblies, painting, and final assembly. B. Process Description and Employee Duties: Most welding operations occur in three departments: fabrication (32 welders), cab assembly (8 welders), and ladder shop (13 welders). Most welding is MIG welding (metal inert gas) on mild steel, with some galvaneal, stainless steel and aluminum also being welded A small amount ofSMA (shielded metal arc, or "stick") welding is also done in the fabrication department Six welders work in other areas ofthe plant (mostly assembly), including two part-time welders in the machine slop. C. Engineering Controls: Local exhaust ventilation (LEV) systems were available at sane welding stations in the fabricator department but these woe not used routinely. HWBUI0007302 IV. EVALUATION DESIGN AND METHOD A Envircxirnenial: Air samples for welding fumes were collected on pre-weighed polyvinyl chloride (PVC) filters. Personal samples were cdlectedby placing the filter cassettes near the breathing-zone ofthe workers. The filter media were connected via tygon tubing to battery operated sampling pumps operating at an air flow rate of 15 liters per minute (LPM). Hie pre-weighed PVC filters were analyzed gravimetrically for total dust and were analyzed via inductively' coupled argon plasma-atonic emission spectroscopy 0CP-AES) according to NIOSH Method No. 73001, a technique that provides fbrthe simultaneous analysis of28 metals of toxicological importance. A list ofthe^ebnents and toeircorrespordir^ analytical liinhs ofdetection is presented in Table 1. Sampling for asbestos was conducted at die brake shoe operation to evaluate employee exposures to airborne asbestos fibers, Personal samples were collected near the breathing zone oftlie anployee responsible for assembling brake shoes and general area air samples were collected in an area where employees woe likely to enter. Both personal and general area air samples were collected on AA 25 millimeter filters connected via tygon tubing to battery powered sampling pumps operating at 3.0 (LPM). All asbestos samples were analyzed via pliase contrast microscopy according to NIOSH method #7400.' Additionally, a bulk material sanple ofshavings from the brake shoe pads was collected and analyzed via polarized light iniooscopy. B. Medical: A structured questionnaire and a spirometry test (a type oflung function test) were administered to study participants. The questionnaire was administered by NIOSH interviewers, and contained questions about respirator/ and other symptoms, smoking history, demographic variables, and occupational history. The respiratory symptom portion ofthe questionnaire was a modified version ofare used in previous NIOSH studies.2 For the purpose ofthis report, a symptom which a worker indicated to be 'better on days away from work" is referred to as a "work-associated symptom." Spirometry was measured with an Ohio Medical Instruments Model 822 dry-rolling seal spirometer connected to a Spirotech dedicated computer. The following spirometric measurements were recorded for each participant the forced vital capacity (FVQ, the forced expiratory volume in 1 second (FEV1), FEV1 /FVC ratio ((FEV1 /FVC)%). and the FEF 25-15%. For a detailed explanation ofdie interpretation ofindividual spirometry' results, see Appendix A HWBUI0007303 Ail current welders at the FWD/5eagrave facility, as determined by company personnel lists, were invited to participate in the study. Current machine shop employees who were not welders (two machine shop employees performed welding on a part-time basis and are included in the welding group) were used as a comparison or "control" group for the welders. On the basis ofthe walk-through inspection, the machine shop work aivironment was considered relatively free ofie^airatory irritants, and it was assumed that welders and machine shop workers would be similar in terms ofother factors that might affect reporting of symptoms. Forty-six current welders and 36 controls completed both the questionnaire and spirometry, and one welder and one control completed the questionnaire, but declined spirometry. Participation rates were 80% for welders and 95% for controls. Six other workers who participated in tire study are not included in the data analysis. Two ofthese workers worked in welding areas but woe not themselves wdders and four had been machine shop employees when the initial list ofstudy participants was created but had been transferred to other departments when the study was performed. For each symptom a prevalence ratio, tire proportion ofwelders reporting a symptom divided by the proportion ofcontrols reporting tire same symptom, was calculated. The prevalence ratio was adjusted fer tile proportion ofament smokers in each group to compute a "snxrking-adjusted prevalence ratio" (PR) with a 95% confidence interval (95% CO, using the Mantel-Haenzel estimate and test-based method, respectively.1 For explications oftlie prevalence ratio, smoking-adjusted prevalence ratio, and 95% confidence interval, see Appendix B. For analysis, symptoms were grouped into 4 categories: 1) lower respiratory tract irritative symptoms; 2) wok-associated lower respiratory tract symptoms - i.e., symptoms which improved on days away from wok; 3) work-associated mucous membrane irritation symptoms - symptoms related to irritation ofthe eyes, nose, and throat that improved on days away from work; 4) other work-associated symptoms-other symptoms, "constitutional'1 in nature, that improved on days away from wok. To analyze the pulmonary function data tire spirometry results ofwelders and controls were compared, using t-tests and analysis ofcovariance4, and an assessment was made ofwhether, among welders, pulmonary function was associated with tire total time worked as a welder at FWD/Seagrave, using multiple linear regression4 "Residual''' spirometry values (observed minus predicted), rather than percent ofpredicted values (oteervedjiredicted times 100), for study participants were used throughout the analysis to adjust for age and height (see Appendix C). Because previous studies have suggested that welding fume may affect smokers and non-smdeers differently, spirometry' data were analyzed separately fix ever-smokers and never-smokeis. HWBUI0007304 EVALUATION CRITERIA A Emironira'italEvahaton Criteria As a guide to the evaluation ofthe hazards posed by workplace erqposures, NIOSH field staffemploy enviOTiiailalevalualimCTheriaforassessiT^ofanirrberofchaTiical and physical agents These cntena are intended to suggest levels ofexposure to which most workers may be exposed up to 10 hours per day, 40 hours per week for a vvortengfif^rKwithait experiencing adverse health effects. It is, however, important to note that not all workers will be protected from adverse health effects iftheir exposures are maintained below these levels. A small percentage may experience adverse health effects because of individual susceptibility, a pre-existing medical condition, anchor a hypersensitivity (allergy). In addition, some hazardous substances may act in cxrmbination with other workplace exposures, the general environment, a- with medications or personal habits ofthe worker to pradice health effects even if tire ocaipational exposures are controlled at the levels set by the evaluation criterion These combined effects are often not considered in tlx: evaluation criteria Also, some substances are absorbed by direct contact with tire skin and mucous membranes, and thus potentially increase the overall exposure. Finally, evahotion criteria may change over the years as new infonralion on the toxic effects ofan agent become available The primary sources ofenvironmental evaluation criteria for the workplace are: 1) NIOSH Recommended Exposure Limits (RELs), 2) tire American Conference ofGovernmental Industrial Hygienists (ACGIH) Threshold Limit Values (TLVs/', and 3) tire U.S. Department of Labor/Oocupational Safety and Health Administration (OSHA) occupational health standards. Often, the NIOSH RELs and ACGIH TLVs are lower than the corresponding OSHA standards. Both NIOSH RELs and ACGIH TLVs usually are based on more recent information than are the OSHA standards. The OSHA standards also may be required to take into account the feasibility ofcontrofling exposures in various industries where tire agents are used; the NIOSH RELs. by contrast are based primarily on concerns relating to the prevention ofoccupational disease. In evaluating the exposure levels and the reoarnTerdalions for reducing these lewis found in this report, it should be noted that industry is required by the Occupational Safely and Health Act of 1970 (29 USC651,et seq.) to meet those levels specified by an OSHA standard. A time-weighted average (TWA) exposure refers to the average airborne concentration ofa substance during a normal 8 to 10-har workday. Some substances hav e recanmended short-tenii exposure limits (STEL) or ceiling values which are intended to supplement tire TWA where there are recognized toxic effects from high, short-tenn exposures. HWBUI0007305 Infonnalion on possible heahh effects ofexoessive exposure to welding fume and selected metals that may be found in voiding fume are provided below: 1. Total Welding fame, not otlierwise classified^7 The health effects associated with exposure to welding fumes are dependant on the toxicity of individual cotrponent metals. This classification applies to welding environments where concentrations oftoxic metals (Le, dranium, cadmium, zinc) are not in excess oftheir respective exposure criteria Usually in these situations the major component ofthe fame is iron oxide or aluminum oxide, depending on whether the base metal is carbon (mild) steel oraluminum. Oxides of these metals are considered nuisance particulates based on their 5 mg/M3 2. Chromium7-8-9 Qiromium compounds can act as allergens in some workers to cause dermatitis to exposed skin. Acute expoaire to chromium dust and mist may cause irritation ofthe eyes, ncee and throat. Chromium exists in clnumales in one ofthree valence states 2+, 3+, and 6+-. Qiromium compounds in the 3+ state are ofa tow order oftoxicity, in tlie 6+ state, chromium coumpounds are irritants and corrosive. This hexavalent fonn may be carcinogenic or norvcarcinogarric depending on solubility, lire less-soluble forms are carcinogenic. Workers in the chromate-producing industry have been reported to hive an increased risk oflimg cancer. Hie known health hazards from excessive exposure to chromium welding fumes are dermatitis, ulceration and perforation ofthe nasal septum, irritation ofdie mucous membranes of die larynx, pliaiynx. conjuctiva and chronic asthmatic bronchitis. 3. Iron oxide fame7-8 Inhalation ofiron oxide feme or dust causes an apparently benign pneumoconiosis tamed siderosk Iron oxide alone does not cause fibrosis in die lungs ofanimals, and the same probably applies to humans. Exposures of6 to 10 years are usually considered necessary before changes recognizable by x-ray can occur, die retained dust gives x-ray shadows that may be indistinguishable from fibrodc pneumoconiosis. 4. Nickel 7AI Metallic nickel and certain soluble nickel compounds as dust or fame can cause sensitization resulting in dermatitis anchor asthma Nickel Rime in high concentrations is a respiratory irritant. Nickel is carcinogenic in animals, and several epidemiologic studies have shown an increased incidence of HWBUI0007306 cancer ofthe paranasal sfousesard lungs arrwng workers in nickd refineries and factories. Suspicion ofraranogmdty has been focused primarily cm respirable particles ofnickel nickel subsulfide, nickel oxide, and on nickel carbonyl vapor. 5. Silver11 Inhalation or ingestion ofsoluble silver (xtmpounds over many years may cause a generalized bluish-black discoloration ofthe skin known as argyria Silver deposits (argyrosis), in the conjunctiva, cornea and lens ofthe eye have also resulted from silver exposure, and decreased night Vision was reported by some affected workers, but no objective irrational deficits could be demonstrated. B. Effects ofArc Welding on Respiratory Symptoms and LungFtrncfion Previous studies hive noted a variety ofacute and chronic health problems associated with arc welding, which have not clearly been attributable to any sinde metal fume or gas exposure, but which may be related to the combined effects ofdifferent exposures created try arc welding. Some metal fumes and gasses generated by welding are respiratory irritants, and symptoms ofeye, nose, and throat inflation as well as cougli, and phlegm production have been repented by welders in association with their work shift12 Welders have been reported to have an increased prevalence ofchronic bronchitis.13-14-15 Some studies have also sliown udders to hue lower pulmonary Unction values than non-wekkrs, including lower total lung capacity (TLCf' and lower FVC and FEV1 .ai(l However, it has not been possible to attribute changes in pulmonary function to specific exposures, aid not all studies have found fewer pulmonary function in welders.15 In addition, it is not known wlietlierdianges in lure: function associated with welding can, in the abserocofsTiokingorotherexpaain^leadtodraicallysignificart Exposures encountered by welders vary' with tlie type ofwelding process, die material welded, and the use oflocal ventilation and personal protective equipment Therefore, it is not possible to make reliable generalizations about health effects ofwelding in all workplaces. Differences in exposures may explain why various studies ofwelders have not produced consistent results. RESULTS AND DISCUSSION A Erreiromiertal; Qualitative and quantitative analypeal results for metals via 1CP-AES and total welding fitnie via gravimetric analysis are presented in Table 2 'I here results drew the presence ofaluminum, barium, calanm, chromium copper, km magnesium, manganese, molybdenum, nickd silver, titanium, and zinc. The range ofairborne concentrations for each ofthese nietals are presented abng with their corresponding environmental criteria HWBUI0007307 Individital air samplirg results ftx the various dqMitmeras are pe^ifed inTables 3 to 6. Environmental fixcurcmtratans are provided for total welding fume, iron oxide, and those other metals (nickel and silver) that were present at concentrations greater than 50% oftheir respective most stringent occupational exposure limits. Additionally, results for total dnomiurn are presented to flbstraie the fact that higher concaifirations ofchromium are present in areas where welding ofstainless steel was performed. The higher concentrations are most likely attributable to chromium VI, a form ofchromium that is present in stainless steeL Total welding fume levels ranged from 0.7 milligrams per cubic meter ofair (mgM1) to 62 mgM'1. One-third ofthe samples had quantities oftotal welding finne greaterthan 50% ofthe AOGIH TLV and OSHA PEL of5 rngM1, and two ofthese sarrpies exceeded these criteria Nickel concentrations ranged from 0.001 to 0.022 mgM1; 1 ofthe 33 samples exceeded the NIOSH RELof0.015 mgM'1 and 4 of33 were greaterthan 50% oftheir most restrictive occupational exposure limit; none exceeded the OSHA PEL of 1.0 mgM1. Silver was detected on 1 of33 samples at an airborne concentration ofO.Ol 5 mgM1, which exceeded tlie OSHA PEL of0.01 mgM\ All other detected metals did not exceed any ofthe environmental criteria Some welding on stainless steel was conducted during the collection ofthree samples. Total chromium in tliese samples ranged from 0.023 to 0.051 mgVn1. Chromium concentrations were 0.010 mg/m1 a less in all other samples. Results ofpersonal and general area air sampling for asbestos in the brake shoe assembly area indicated that airborne concentrations ofasbestos were below tlie analytical limit ofdetection. However, a bulk sample of material shavings fan tlie bake shoe pads were collected and submitted foranalysis. This bulk sample showed that this material contained 10 - 20% chiysotile asbestos. Medical Table 7 summarizes a comparison ofwelders and controls with respect to sociodemographic characteristics. The welders were somewhat younger than tlie controls with 57.5% and 37.8%, respectively, being 45 years old or less A higher proportion ofwelders (85%) had mere than 12 years of education compared with controls (2.7%). Fewer welders (255%) than controls (40.5%) were current smokers, bit welders had a higher proportion ofever-smokers and more pack-years ofsmoking Controls had a slightly longer average length ofemployment at FWD. Among welders, the average number ofyears welding was 20. Land a high proportion ofthose years (17.7, on average) was spent welding at FWD Corp. None ofthe controls had ever worked as a welder. Table 8 shows a comparison ofsymptom frequencies in welders and ocntrols, stratified by current smoking status, and tb sneking-adjusted prevnlenoe ratio for each symptom Welders were slightly less likely than controls to have a usual cough (PR=0.7,95% Cl 05 -12) or usual phlegm (PR=0.8,95% Q 05 -1.4) than controls However, welders were more likely to report symptoms ofchronic bronchitis (PR=27 95% HWBUI0007308 Cl = 0.7 - 9.9). As expected, chronic bronchitis w more frequalanwng current smokos than current non-smokers, bit 14% ofrovsiiiokir^ welders iqxxtedchOTicbroreiiitisocxrpired with rone ofthe non-smoking controls. Welders were also more likely id report having had a chest illness that kept than from their usual activities for as much as a week during the past three years (PR=3.6,95% Q 0.9 -14.5). None oftoe differences was statistically significant, as shown by the 95% confidence intervals, which include 1.0. Welders were more likely than controls to report lower respiratory tract symptoms that improved on days away from work. The PRs for this group ofsymptoms ranged from 12 for weak-associated phlegm to 3.9 for work-associated dyspnea None ofthese PRs differed significantly from 1.0. Three wok-associated mucous membrane irritation synptoms were more common in welders than in controls, irrespective ofsmoking status. For eye-irritation (PR=6.4,95% Cl 1.7 - 23.9) and throat irritation (PR = 3.8,95% Cl 1.0-143), the differences between welders and controls were statistically significant Work-associated nasal congestion was also more frequent in welders (PR=22,95% Cl 0.9 5.3). Work-associated nausea and headacltes were more frequent among welders than controls, and tliese differences were accounted for by non-smokers. Work-associated fever was only reported by 2 workers, both welders. Overall, the prevalence ratio exceeded 1.0 for 10 ofthese 12 work-associated symptoms, although only two oftoe elevated prevalence ratios were statistically significant The frequencies ofsymptoms reported by welders in the fabrication, cab assembly, and ladder departments are town in Table 9. For most symptoms, the fewest prevalences were reported by ladder shop employees. This group also had the fewest proportion ofsmokers. Thirty-one patent offabrication department employees reported synptoms ofchronic bronchitis and thirty-eight percent reported work-associated cough None oftire welders in the other two departments reported these symptoms. Results for spirometry test residuals (observed minus predicted) fa welders and controls are summarized in Table 10. As indicated by tire negative values ofthe residuals, current and ex-smokers had lower pulmonary function than predicted for tlieir age, height race, and sex. Comparing ever-anokmg welders to ever-smoking controls, the welders had lower resided spirometry results (greater negative deviation from predicted) titan controls for FEV1, (FEV1 /FVC)% and FEF 25-75. However, the differences woe generally small and not statistically significant controlling for current smoking and pack-years smoked Among never-smokers, welders had lower spirometry residuals than controls for FEV 1, FVC, FEV 1/FVC% and FEF 25-75, and tliese differences were also not statistically significant Fewer welders than controls had abnormal spirometry according to the criteria described in Appendix A Three welders and four oontrols had obstructive abnormalities, one welder and three controls had restrictive HWBUI0007309 abnonnalities, and one wider and one control had mixed (obstructive and restrictive) ahxxmalities. All subjects with abnormal results were current or ex-smokets. The differences in the proportions ofwelders and controls with various types ofabnonnal test results were trot statistically significant by Fisher's exact test Table 11 summarizes the regression analysis ofspirometry residuals (dependent variables) among welders in terms ofthe estimated regression coefficients (Us) for years worked as a welder at Four Wheel Drive Corporation These are estimated separately for ever-smokers and never-smokers. For ever-smokeis, the coefficients are adjusted for current smoking status and pack-years smoked Among ever-smokers, there was a statistically significant, inverse relationship between years worked as a welder at FWD Cap. and the following residual spirometry results: 1) residual FEV1 (observed FEV1 minus predicted FEV1) (G = -36cc per year, 95% Cl -56 - -16cc/year); 2) residual (FEV1/FVC)% (6 = -0.35% per year, 95% Cl -0.68 - -0.04% per year); and 3) residual FEF 25-75 (B= -65ccfyear, 95% Cl -111 --19co(year). The regression coefficient for years welding at Fair Wheel Drive was negative, but not significantly different from 0, when residual FVC was the dependant variable. Figure 1 shows FEV1 residuals plotted against years worked as a welder at Four Wired Drive for ever-snoking welders, and tire "best-fitting" line from the relationship between those two variables asjustod for smoking status and pack-yeais. Figure 2 shows a similar plot with (FEV1/FVC)% on the y axis. From this plot, it is apparent tint the negative slope oftire regression line for all observations is largely due to 1 observation with 41 years welding at FWD Cotp. and (FEV1/FVC)% 34% less than predicted Hie regression line drown excluding that "outlier" observation has a slope of-0.13% per year (95% ofCl -0.44 - 0.18% per year). Among weldets who were never-smokers, there were no statistically significant associations between spirometry residuals and yens worked as a welder at Four Wired Drive, but all regression coefficients were positive DISCUSSION A. Environmental: It should be noted that during tire environnrental survey ofMarch 1987 conditions were not representative of everyday operations. Production rates were below nonnal and the tack welder was not in use in the ladder slrop during the day sampling was conducted in that area The tack welding operation was not ventilated and oaildbea significant source ofnrctal fumes in that drop wlren operating. Two ofthe metals detected nickel and chromium, have NIOSH RELs that are relatively stringent compared to other applicable environnrental entena Nickel compounds are considered by NIOSH to be suspect carcinogens. Analyses ofsanples collected show the presence ofnickel above the NIOSH REL. The results ofanalyses for total chromium are all below tire applicable environmental criteria However, the analyses performed do not distinguish between hexavaknt chromium (chromium VI) and other fonnsof chromium In each instance where welding was corductedon stainless steel the amounts ofdiromiumwae HWBUI0007310 aYisiderably higher than in areas where stainless Seel was rirt iced. This difference would most likely be due to die presence ofchromium VI which is oommonly found in stainless steel and is considered by NIOSH to be a suspect human carcinogen Despite the feet to the brake shoe machining process was equipped with local exhaust ventilation, the accumulation ofvisible particulate material machined Iran the brake shoes was noted throughout the area This creates the potential for the qjread ofasbestos-containing materials to other areas ofthe plant Abo,the worker observed in this area was not wearing appropriate personal protective equipment Medical: The medical survey was intended to assess any relationship between work as a welder at Four Wheel Drive and respiratory' symptoms and pulmonary function. A higher proportion ofweldets tittn controls reported most ofthe symptoms surveyed, controlling for the effect ofsmoking The association between work as a welder and symptoms was especially consistent for work-associated symptoms. Although elevated prevalence ratios were statistically significant for only two work-associated symptoms, ten ofthe 12 work-associated symptoms had prevalence ratios greater than 1.0. If(lie "tree" frequencies ofwork-associated symptoms among weldets and control workers under the conditions at FWD Corp. were equal one would expect, on average, 6 ofthe 12 prevalence ratios to exceed 1.0 and 6 to be less than 1.0. The probability of 10 or more symptoms occurring more frequently in welders by chance is 0.019 (exact biixmiual probability). Most ofthese work-associated symptoms are suggestive ofexposure to reqairatory tract irritants. This finding is consistent with the known properties of some components ofwelding fume and with symptoms reported by other workers exposed to welding fume12 Symptoms ofchronic bronchitis were reported more often by welders than controls, though the difference was not statistically significant Chronic bronchitis is a known consequence ofcigarette smoking17, and may be caused by repeated airway irritation by cigarette smoke. Chronic bronchitis symptoms have been associated with welding in otiier studies1-'1415 and may be due to repeated exposure to respiratory irritants present in welding fume. Cough and chronic bronchitis appeared to be associated with work m the fabricating area This may be related to tire finding ofthe higlies levels oftotal welding fume exposure in this department during the survey. Among ever-smoking welders there was an association between longer tenure as a welder at FWD Corp. and poorer performance on spirometric measures ofairflow (FEV1 and FE25-75). In this group, negative, but non-significant, regression coefficients were also estimated for years welding at FWD ootp. when FVC and (FFVl/FVQK) woe the dependent variables (excluding 1 outlier from the (FEVl/FVQP/o regression analysis). Becattse oflhe limited bettoyofpulrnaiaiyluncticxi tests we cxxM reasonably cany oit in a fidl setting we woe unable to determine whether reduced king volumes, reduced airflow, orboth, amounted for HWBUI0007311 (he association observed between yeais ofwelding at Four Wheel Drive Corporation and lower spirometry results (see Appendix A). We did not find a similar association between welding and pulmonary function among never-snokers. These findings suggest that past exposure of1welding fume at Four Wheel Drive Corp. and cigarette smoke may have "interacted" to cause a combined adverse effect on pulmonaiy function which is greater than oq^eded from their individLtd effects. This does not mean that smoking is the "cause" ofthe tower pulmonaiy function seen among ever-smoking welders with longer duration ofwelding. The association between pulmonaiy function and yeais welding at FWD Cap. was present after controlling fathe effects ofsmoking in the group ofever smokers. Tlie apparent interaction between cigarette smoke and welding observed in this study is consistent with some cither studies.16,18 More oonirois than weldas had abnormal spirometry results, but the numbers ofabnormal results were small, and this observation is consistent with a chance finding. Our study was not designed to attribute a cause to any individual test result and focused only on group comparisons. Several limitations ofair survey need to be mentioned This was a cross-sectional study ofcurrently employed welders. Since workers who develop adverse health effects from welding may be mote likely to diangejobs, observations limited to current workers may imderestiinate tlie advene effects ofwelding. Such a study cannot directly measure dinnges in health due to an exposure, because individuals ate only studied once. No ever-smoking welders with toween 9 and 18 years oftenure at FWD Coip. were available fa testing nor were historical data on welding fume exposure available. Therefore, the relative effect ofpast versus more recent welding fane exposure on lung fimetion cannot be assessed VIII. CONCLUSIONS 1. Employees waking in tlie fabrication area (department #02) were exposed to concentrations oftotal welding fume in excess ofthe ACGIH TLV mid tlie OSHA PEL and to concentrations ofnickel and silver in excess ofdie NIOSH REL and OSHA PEL, respectively. 2. Welders at Far Wheel Drive currently report more wotk-associated symptoms ofirritation oftlie mucous membranes ofthe eye; nose, tliroot and lower respiratory tract and have a higher prevalence ofchronic bronchitis symptoms tlian do txm-welding workers, and these symptoms are likely to be caused by excessive exposure to welding fume. 3. Duration ofwork as a welder at Far Wheel Drive Corporation was associated with lower values of FEV1 and FEF 25-75 among ever-smokers. Tltis finding suggests that tlie cumulative effect ofpast exposure to welding fumes, under conditions at this facility, have interacted with cigarette smoking to cause a decrease in those lung function tests. 4. Eiwironmenlal measurements suggested a potential fa significant exposures to dramim VI during stainless HWBUI0007312 steel adding. Observations suggested a potential for significant exposures to asbestos in the brake shoe assembly area RECOMMENDATIONS The following rraxirnendations woe discussed with representatives ofthe management and tlie union during the closing conference on March 12,1987. These iraaiTrnendatxxts should be Hipfarientedifthey have not already been completed 1. General and local exhaust ventilation (LEV) systems should be installed in all welding departments to reduce the levels ofmetal fume. 2. Since welding and other firaie-prodiicing operations are routinely perfomed in tlie cab assembly area (dept #03), the fabrication area (dept. #02), and the ladder shop (dept #04), exhaust ventilation should be used to remove metal fumes. Ideally, freely moveable fume hoods with flexible deling should be used which would allow tlie welder to position the hood as dose as practicable to the piece being welded 3. An LEV system should be installed in tlie ladder sliop at the tack welding operation This type system could be easily installed and would significantly reduce airborne ootxentrarions ofmetal fumes wlien this operation is running. 4. Ureal exlmust ventilation (LEV) systems oftie type discussed above were available at the welding bootlis in the fabrication area (dept #02) however, tliese systems were old and were not being used during tlie time of our survey. These systems slxxild be repaired or replaced as necessary, and employees should be instructed in the correct usage oftliese systems and encouraged to use the systems. 5. Portable LEV systems should be used wIxti welding or anting in confined areas, such as inside cabs. In non-confined areas LEV systems shoukl be used, partiatLnrly when working with stainless steel, a primary source ofcarcinogenic hexavaJcrit chromium (Cr VT), nickel and oilier toxic metals. When using LEV systems, the hood should be placed as close as practical to the arc site. Provisions should be made to ensure that welding fumes ofthe toxic metals are not exhausted into an area where other workers are present Additionally, make-up air for amfined spaces where LEV systems are used should be clean 6. In situations where the use ofLEV systems is impractical workers slxxild be provided with appropriate respiratory protection Supplied air respirators arc required in confined graces in the absence ofsufficient contaminant removal and'or make-up air. This type ofrespirator should also be used when welding on stainless steel in non-confined work spaces wiierc use ofan LEV system is impractical 7. These wcikers welding for prolonged periods of'nine m one location should use a fan or LEV system to prevent fumes from entering hisher breathing zone. HWBUI0007313 8. Welding curtains should be putdiasedand used as much as possible to minimize ifavbld (UV^ exposure ofother workets in the area 9. All welding ardainirgqKralkreshaildoaTpIy with the requirarients outfitted in (he General Industry Occupational Safety and Health Standards, OSHA (29 CFR1910252). 10. The asbestos brake shoe area should be isolated from other areas ofdie facility to prevent the spread of asbestos fibers. 11. All accumulated asbestos fibers in the brake shoe areas should be cleaned up using appropriate procedures and a regular housekeeping schedule should be implemented to prevent future accumulation of asbestos containing materials. 12. The removal ofaccumulated asbestos fibers in the brake shoe area should be accomplished by the use ofa vacant) system, dry sweeping teclmiques should not be used. Ideally', a central vacuum system equipped with a ltigli efficiency particulate air (HEPA) filter should he installed A portable vacuum systan equipped with a META filter oould be used as an alternative to the installation ofa central vacuum system. Vacuum "collectors" shark! be emptied and their contents disposed ofusing appropriate procedures. 13. Appropriate protective coveralls sharld be provided and worn by anptoyees working on the brake shoe machining operation or dean-up ofthat area These slxxild be laundered or disposed ofproperly, depending on the type used. 14. Until effective engineering controls are 'installed, the use ofan appropriate respirator should be required and enforced 15. When the installation ofengineering controls is completed, die areas should be monitored for airborne concentrations oftotal welding fume, chromium VI, nickel and other metal fumes in all welding areas and for asbestos at the brake shoe operation to determine the effectiveness ofthese controls. 16. Hie present respirator program shaild be thoroughly reviewed and updated to ensure that the respirator program is in compliance with all requirements of29 CFR 1910.134. 17. The present program for blood lead monitoring should be reviewed to ensure that it is in compliance with all requirements of29 CFR 1910.1025,19 including the use ofan OSHA-approved laboratory to perform the blood lead measurements. HWBUI0007314 REFERENCES 1. National Institute for Occupational Safety and Health. NiOSH manual ofanalytical methods, 3rd Edition Cincinnati, Ohio 1984. (DHHS (NIOSH) publication no. 84-100). 2. Petersen M, Custelian RM. Prevalence ofChest Symptoms in Nan-Exposed Blue-Collar Workers. JOM 1984;26:367-74. 3. Kleinbaum DG. Kupper LL and Morgen-stern H. Epidaruolqgic Research Lifetime Learning Publications, Belmont, California 1982. 4. Keinbaum DG and Kupper LL Applied Regression Analysis and Other Multivariable Metliods. Duxbury Press; Boston, 1978. 5. Fbnkinson.IL Pulmonary function tesdr^j; in tlie screening ofworkers: guidelines for instrunientation, perfonnance, and interpretation J. Occup. Med. 1986; 28:1081-92. 6. American Conference ofGovernmental Industrial Hygienists. Tlueshold limit values for diemical substances and physical agents in the workroom environment and biological exposure indices whit intended changes for 1987-88. Cincinnati, Ohio: ACGfH, 1987. 7. American Conference ofGovernmental Industrial Hygienists. Doannentation ofThreshold Limit Values and Biological Exposure Indices. Fifth Edition Cincinnati, Olio: ACGIH. 1986. 8. Proctor NH and Hughes JP. Chemical hazarels ofthe workplace. Philadelphia: IB. Lippencott Company, 1978. 9. National Institute for Occiipational Safety and Health. Criteria for a recommended standard: occupational exposure to chromium VI. Cincinnati, Olio. National Institute for Occupational Safety and Health, 1976 (DHHS (NIOSH) Publication No. 76-129). 10. National Institute for Occupational Safety' and Health Criteria for a recommended standard: occupational exposure to inorganic nickel. Cincinnati, Oliio. National Institute for Occupational Safety and Health 1977 (DHHS (NIOSH) publication no. 77-164). 11. National Institute for Occupational Safety and Health Occupational diseases: a guide to derecognition. Revised ed. Cincinnati Oliio. National Institute for Occupational Safety and Health, 1977 (DHEW (NIOSH) publication no. 77-181). 12. National Institute for Occupational Safety and Health Health Hazard Evaluation Report No. HETA 85-030-1693. Cincinnati. Ohio. National Institute for Occupational Safely and Health, 1986. HWBUI0007315 13. Alkborkhanzadeh F. Long-term Effects ofWelding Fumes Upon Respiratory Symptoms and Pulmonary Function J. Occup. Med 1980; 22:33741. 14. OxhojH, Bake B, dal Effects ofElecJric Arc Welding In Ventilatory Lung Function. AichEnvHeaMi 1979;34:211-217. 15. Sjogren B, Uliuaraon U, and Tech D. Respiratory Symptoms and Pulmonary Function Among Welders Working with Aluminum, Stainless Steel and Railroad Tracks. Scand J Wok Environ Health 1985;11:27-32. 16. Peters JM, Murphy RL, et aL Pulmonary Function in Shipyard Welders. Arch Env Health 1973; 26:28-31. 17. Parkes WR. Occupational Lung Disorders, Buttetworks, London, 1984. 18. Mur JM, Teculesai D, et al. Lung Function and Qinical Findings in a Cross-Sectional Study ofArc Welders. Int Arch Occup Environ Health 1985:57:1-7. 19. Occupational Safety and I lealtli Administration OSHA safety and liealth standards, 29 CFR 1910. Occupational Safety and Health Administration, revised 1983. 20. Knudson RJ, Slatin RC, et al. Hie Maximal Expiratory How-Volume Curve. Am Rev Resp DLs 1976: 113:587-600. HWBUI0007316 XI. Al JTHQRSHIP AND ACKNOWLEDG iffliasii Report Prepared by; Thomas Matte, M.D., M.P.H. Medical Officer Surveillance Coordinating Activity Office ofthe Director Daniel Almaguer, MS. Industrial Hygienist Industrial Hygiene Section Hazard Evaluation and Technical Assistance Branch Originating Office: Division ofSurveillarce, Hazard Evaluations & Field Studies Hazard Evaluation and Tedinical Assistance Branch Laboratory Analyasis: Utali Biomedical Laboratory xii. Salt Lake City, Utah rnoNdistribi and ayah abii tty of detcrmination report Copies ofthis Dwennination Report are currently available upon request Iran NIOSH, Division ofStandards Development and Technology Transfer, Resources and Dissemination Section, 4676 Columbia Pathway, Cincinnati, Ohio 45226. After 90 days the report will be available through the National Tedinical Information Services (NTIS), Port Royal Road, Springfield, Virginia 22161. Information regarding its availability through NTIS can be obtained from NIOSH publications office at the Cincinnati address. Copies ofthis report have been sat to the following: A Four Wheel Drive Corporation B. Allied Industrial Workers Union, Milwaukee, Wisconsin C. Allied Industrial Workers. Local 816 D. U.S. Department ofLabor, OSHA - Region V E NIOSH, Cincinnati For the purposes ofinforming the affected employees, copies ofthe report should be posted in a prominent place accessible to the employees, for a period of30 calendar days. HWBUI0007317 Ebnenl Table 1 Elements Analyzed by ICP-AES and Their Corresponding Analytical Limits ofDetection Four Wheel Drive Corporation Clintonville, Wisconsin HETA 86-524 Analytical Limit ofDdection (miaograms per sample) Akininm Artnrmy Arsenic Boron Barium BuyUiun Calcium Cadmium Cobalt Grramium Copper Iron LTnlhanum Magnesium Manganese Molybdenum Nickel Lead Selenium Sihvr Tm Tefluiim Tkdlium Titimm Vanadmin Yttrium Zir Zirconium Note l(XX)micK]grarns=lnTiIlignm 10 10 5.0 10 1.0 1.0 5.0 1.0 1.0 1.0 . 1.0 1.0 5.0 1.0 1.0 1.0 1.0 2.5 10 2.5 10 10 10 10 10 1.0 1.0 10 HWBUI0007318 Tabie2 Metals defected on pereonal breathing zone air samples Four Wheel Drive Corporation CHntorrville, Wisconsin HETA 86-524 March 9-12,1987 Substance (Metal) Ran< (mg/M-) Number ofsamples detected on NIOSH REL (mg/M3) ACGIH TLV (mg/M3) OSHA PEL (mg/M3) Total udding furre 0.7 -6.2 Aiininm 0.017-0.16 33/33 9/33 ... 5 5 -- 5 ... Barium 0.001 - 0.005 9/33 -- 0.5 0.5 Calcium Chromiinn 0.011-0.22 0.002-0.051 3233 21/33 --2 5 * 0.5 1 Copper 0.003-0.022 32/33 -- 0.2 0.1 Iron Magnesium Manganese 0.17 -2.6 0.003 - 0.063 0.014-0.44 33/33 3233 3333 -- 5 10 ... 10 15 ... 1 5-C Molybdenum 0.002 - 0.010 1633 --5 5 Nickel 0.001 -0.022 1733 0.015 1 1 Silver Titanium 0.015 0.091 133 133 -- 0.1 0.01 ... 10 15 Zinc 0.003- 1.2 3333 5 55 C - an arptoyee's exposure shall at no time exceed the ceiling value *The NIOSH RELs for chraniiurn rompounds distinguishes chromium (VI) compounds which are carcinogenic (REL 0.001 mg/m*) and chromium (VI) compounds which are rornairinogenic (REL 0.025 mg/m3). These RELs are not applicable for total chromium, which was measured in this study. HWBUI0007319 Tabic 3 Personal air sampling results for WckSiig Fumes in Department #03 Four Wheel Dive Cotporation Ginttnvilb, Wicordn HETA 86-524 March 9-12,1987 Ditc Job (type steel) SmpleTimc (minute;) Stimplc Volume (litas) EnviiaiiiwTtalCaieaTlr.tliCTtlnTt'M1) Toed Tool Iron Wdding Giarmrn Oxide Fume 3.1 MW vmi 3/09,87 3.1 MW 3/09/87 3.1MW 3/09W 3,09,87 Ctili asset nbly (stainless) Gib ttssembly (mikl gilv.inca]) Rnofttssoibly (mild, gahtmil) Gib assembly (mild, pilv.trcil) Gib assembly, side panel (mild, gylvtineal) Cab assembly (mikl jsihancul) MLsc. Misc. 436 431 428 425 430 424 415 414 654 646 M2 638 645 636 622 621 3.8* 0.029 0.83 22 0.006 0.70 2.4 0.005 0.83 1.4 ND 0.33 1.4 0.002 0.43 2.6* 0.004 0.85 3.2* 0.005 1.5 3.0* 0.004 0.76 ENVIRONMENTAL CRITERIA NIOSH REL ACCIHTLV OSHA PEL * - greater dun 50! 0 ofdie most stringent occupttmil cntcra lor diis substance ND - not detected -- 5 5 -- 5 10 Nickel Silver 0.010* 0.002 0.002 ND ND ND 0.002 ND ND ND ND ND ND ND ND ND 0.015 0.1 1 -- 0.1 0.01 HWBUI0007320 Table 4 Pasonal air sampling icults for Welding Fumes in Department #02 Four Wheel Driue Cotporanon Obonvi!li Wkmtin HETA 86-524 March 9-12,1987 Dale Job (type steel) Sample Tine (minutes) Simple Volume (liters) EiivTCmioitilCcnOTir.iiioa(nMM,1l_ Total Total Iron Welding Chromium Oxide Fume Nickel SiKcr 3/MW 3/!()W 3/I0W 3/MW 3/MW 3/MW 3/I0W 3/10/87 3/I0W 3/l()W 3/10.87 3/10W 3/1OW Fnmx')iv(mikl) Fnmx-line(mikl) Frame lbtjmiki) Booth 15 (tjihtinea]) Booh `/(gnlv.meal) Bcxtlt K(ahmhiin) Bootli 11 (aluminum, bus) Funix- Ihx-fgutvjxaL stainbs) Fr.uix- lit; (mild) Bootli 2. sick welding " (milti jaiNuixsil, sciinlcss) Boodi 12. stick wekiirg (mild) Next to Boodi 12(gal\aixal) 475 300 470 463 453 455 450 446 448 155 285 441 437 ENVIRONMENTAL CRITERIA * - greater thin 50%ofdt mot stringait occupational email for tliis substance - exawh stritwtt acaipatiatial entail for diis subtext ND - not detected 712 450 705 694 6X0 682 675 669 672 232 428 662 6.% NIOSH REL ACGIHTLV OSHA PEL 3.9* 3.4* 5.6** 6.2** 2.2 I.S 1.9 22 3.3* 1.7 4.5* 2.1 3.1* .... 5 5 O.iXU ().(X)8 0.(X)7 O.IXM O.fXM 0.005 0.003 0.051 0.010 ND 0.023 0.004 0.008 1.1 1.1 2.6* 0.79 0.60 0.29 0.25 0.79 1.4 0.69 1.5 0.60 0.90 0.002 0.008* 0.003 0.1X12 0.002 (1.002 0.001 0.022** 0.003 ND 0.008* 0.005 0.005 ND ND ND ND ND ND 0.015' ND ND ND ND ND ND __ 5 die most ** 10 0.015 1 __ HWBUI0007321 Djc Job (t)pc steel) 3/1I/X7 3/11/87 3/1I/S7 3/11/87 3/11/X7 3/11/K7 3/11/87 3/11*7 3/11*7 Lxkkr <4xp (mild) Ladder shop (mild) Ladder sirqp(mikl) Lxklershop(mikl) Ladder drop (mild) Ladlershop (mild) Ladder shop (mild) Ladder shop (mild) Lrdderslicp(mild) ENVIRONMENTAL CRITERIA ND-not detected Table 5 Personal air sampling results for Wekfing Fumes in Depmntrt #04 Four Wlieel Drive Corporation Giitttiville, Wrcorcan HETA 86-524 March 9-12,1987 Sample Tint (minues) S:myL* Volume (lilCJN) Fnvimtunertnl Ponccutr.ilioti (nts^M3) Total Total Iron Wcklhig Omnium Okie Fune 4,SI 722 47S 717 475 712 470 705 466 699 433 650 463 694 457 686 455 682 0.7 1.0 1.7 1.0 1.3 1.5 1.8 1.5 1.1 NiOSH REL ACGIHTLV OSHA PEL -- 5 5 ND 0.21 ND 0.31 ND 0.55 ND 0.28 ND 0.49 ND 0.48 ND 0.46 ND 0.4S ND 0.31 ... 5 10 Nickel SiKcr ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND 0.015 0.1 1 -- 0.1 0.01 HWBUI0007322 Tabic 6 Personal air sampling results for Welding Furres in Departments #23, #22, and #16 Four WkI Drive Corporation Ginniville, Wktruin HETA 86-524 March 9- 12,1987 Qtfe loh (type slctl) Simple Tine (minutes) Simple Volume (facts) Enviramxntil CaxenmiticntnyAT) Total Total Iron Wei.Hit; Oraimmi Oxide Fume 3/12/87 3/12/87 3/12/87 Final tK'xinbly, dpt, #23, (misc. welding) Final assembly. dpt. #22 (misc. vvckJirc) Find assembly, dept # 16, (mire, welding) 460 459 455 m 688 682 0.8 0.003 0.17 0.9 ND 0.19 1.0 0.003 0.31 ENVIRONMENTAL CRITERIA ND-noteletccted NIOSH REL acgihtlv OSHA PEL ... 5 5 5 10 Nicke-I Sibcr 0.002 ND ND ND ND ND 0.015 0.1 1 -- 0.1 0.01 HWBUI0007323 TABLE7 Comparison ofDenTOgraph.se Variables, Smoking, and Occupational History in Welders and Controls Age % 35 years or less % 36 to 46 years % 46 to 55 years % 55 years and older Welders (N = 47) 28.8% 21.1% 14.9% 27.7% ET n Controls 16.2% 21.6%> 32.4%, 29.1% Education % less than 12 years % 12 years % more than 12 years 25.5%) 66.0% 8,5%. 27.0% 70.3%, 2.1% Stinking % current smokers % ex-smokers % never smokers 25.5%, 42.6%, 31.9% 40.5%, ' 32.4%, 27.0% Pack-years (mixing ever snxikeis) mean S.D. 23.7 24.6 18.1 15.0 Years worked at FWD mean S.D. 19.0 21.2 11.3 9.6 Years worked as welder mean S.D 20.1 11.1 -0-- Years worked as Welder at FWD main S.D. 17.7 11.3 -0-- Years worked as Machinist at FWD mean S.D. 0.7(1) 3.0 19.9 10.2 (1) Three current welders worked as machinists in the past HWBUI0007324 TABLE 8 Comparison of Symptom Frequencies In Welders and Controls CURRENT SMOKERS Welders Controls CURRENT NON-SMOKERS Welders Controls Number of participants 12 15 35 22 Lower Respiratory Tract Symptoms: usual cough usual phlegm episode of cough and phelgm coughed up blood wheezing chest Illness dyspnea 5B* 33* 33* 17* 25* 17* 25* 73* 60* 13* 13* 27* 7* 40* 29* 41* 37* 36* 29* 18* 6* 5* 23* 18* 20* 5* 31* 23* Chronic Bronchitis 25* 20* 14* 0* Work-associated (3) Lower Respiratory Symptoms: cough phlegm' dyspnea wheezing 42* 17* 8* 17* Work-associated Mucous Membrane Irritation: nasal congestion eye Irritation nosebleeds throat Irritation 33* 33* 0* 25* Other Work-associated Symptoms: nausea headache lightheadedness fever 8* 25* 17* 8* (1 ) prevalence ratio (2) 95* confidence Interval (3) "better on days away from work" (4) zero In denominator 13* 42* 7* 13* 13* 13* 0* 7* 7* 27* 20* 0* 14* 9* 31* 13* 9* 0* 14* 5* 29* 14* 26* 0* 3* 5* 17* 5* 11* 0* 29* 9* 11* 9* 3* 0* Smoking -Ad justed PR 95* Cl (1) (2) 0.7 0.8 l.B 1.3 1.1 3.6 1.0 2.7 (0.5 1.2) (0.5 - 1.0 (0.8 4.1) (0.1 - 13.1) (0.6 - 2.2) (0.9 - 14.5) (0.5 - 2.1) (0.7 < 9.9) 2.3 (0.8 - 6.2) 1.2 (0.5 - 2.5) 3.9 (0.4 - 36.4) 2.0 (0.5 - 7.6) 2.2 (0.9 - 5.3) 6.4 (1.7 - 23.9) 0.6 (0.0 - 9.6) 3.8 (1.0 - 14.7) 4.7 (0.5 - 40.7) 1.8 (0.7 - 4.5) 1.0 (0.3 - 3.2) (4) HWBUI0007325 TABLE 9 Comparison of Symptom Frequencies for Welders In Fabrication. Cab Assembly, and Ladder Departments Fabrication Cab Assembly Ladder Shop Number of participants 26 Current Smokers 31* Lower Respiratory Tract Symptoms usual cough usual phlegm period of increased cough and phelgm coughed up blood wheezing chest illness dyspnea 62* 66* 31* 31* 27* 23* 35* Chronic Bronchitis 31* Work-associated (1) Lower Respiratory Symptoms: cough phlegm dyspnea wheezing 38* 35* 12* 19* Work-aasoc1st ed Mucous Membrane Irritation nasal congestion 38* eye irritation 31* nosebleeds 4* throat irritation 23* Other work-associated Symptoms: nausea headache lightheadedness fever 15* 4* 4* 8* (1) "better on days away from work." 8 25* 0* 38* 38* 0* 38* 25* 50* 0* 0* 25* 13* 25* 38* 50* 0* 25* 38* 13* 13* 0* 7 14* 14* 29* 29* 29* 0* 0* 29* 0* 0* 29* 0* 0* 14* 14* 0* 0* 14* 0* 0* 0* 0 HWBUI0007326 TABLE 10 Comparison ofSpirometiy Test Residuals (1) in Weldeis & Controls Number Tested FEV1 Residual (cc's) Smoking Status Welders Controls Current Ex Never 11 15 20 11 15 10 Smoking Status Current Mean -97 (S.E.MX2) (211) Mean -91 Ex -182 (116) -69 Never 137 (131) 241 (S.E.M.) (176) (200) (111) P Value 0.88(3) 0.58(4) FVC Residual (cc's) Current Ex Never 100 - 17 115 (228) (116) (140) -72 6 192 (202) (211) (212) 0.71(3) 0.70(4) (FEV1/FVC) Residua] (%) Current Ex Never -6.5 -5.3 -0.7 (2.4) (2.0) (1.4) -3.2 -4.5 0.2 (2.6) (2.5) (0.7) 0.52(3) 0.61(4) FER25-75) Residual (cc/second) Current Ex -1284 -1418 (446) (249) -845 -1186 (356) (460) Never -447 (389) -300 (273) (1) (cbervodRHA-pniksxlieiit]*halcnsochasita.aijEi2 (2) SerchdsnrctffTssn (?) pvakrRrp^J FwofcSflbmrhm^baw^wddKirdcmlriii^nT^ami^a^ii^a^infcfcrQimTnd^asiBadpKkAejsmTkBd (4) p \tiki? kr R>s airpRr\: men n wAiis arri arn^ ami; iwrsnim. 0.47(3) 0.78(4) HWBUI0007327 TABLE 11 Regression Coefliderts for Spirometry Test Residuals (1) versus Years Worked as a Welder at FWD Corporation Dependant Variable Units of Coefficient FEV1 Residual cdyear FVC Residual cdyear (FEV1/FVC) % Residual `I'Vyear FEF 25-75 Residual cdyear Current & Ex-Smokers (2) R2 Coefficient 95% Cl -36 (-56--16) 0.34 -20 (-44-4) 0.11 -0.35 (-0.68--0.04) 0.17 -65 (-111 --19) 0.24 Never Smokers Coefficient 95% Cl 19 (4-42) 17 (-9-34) 0.12 (-0.15-0.39) 26 (-50-102) R: 0.19 0.14 0.06 0.04 (1) [observed test result - predicted test result (based on sex, age, race, and height31)] (2) Adjusted for current smoking status and pack-years ofsmoking HWBUI0007328 FEV1, (Observed - Predicted), liters Graph 1 FEVi, Observed - Predicted Value, Versus Years Worked as a Welder at FWD, Ever Smokers 1 .2 1 o.e 0.6 0.4 02 O -0.2 -0 4 -0.6 -o.e -1 -1.2 -1.4 -1.6 HWBUI0007329 (FEYI/FYOX, Observed - Predicted Value Graph 2 (FEVi/FVC)%, Observed - Predicted Value, Versus Years Welding at FWD, Ever-Smokers lines HWBUI0007330 Appendix A Interpretation oflndividual Spirometry Tests The purpose ofthepulinonaiy function tests was to determine iflong-term aupbyees, as a group, had evidence ofreduced lung function that could be attrihled to exposures, including welding fame, at Four Wheel Drive. The following spirometric measures were used to determine whetheran individual had prfa>onaiyfarK*ai results outside the conventional range ofnormal: forced vital capacity (FVQ, 1-second forced expiratory volume (FEV1) and calculation ofthe ratio (FEV1 /FVC)%. FV'C is the total amount ofair that can be forcibly exhaled after a full inspiration; FEV1 is the amount ofairexhaled during the first secaxl ofa forced expiratioa Any condition shat impairs FVC also impairs FEV1 (but not necessarily (FEV1/FVC)%), but tine reverse is not true. Conditions that impair FEV 1 do not necessarily impair FVC. FEV1 and FVC are evaluated by comparing them to "predicted" values tint take into account age, height, sex, and race. Pulmonary function is considered "nonnal" ifthe FVC and FEV 1 arc 80% or more- oftlxir predicted values and (FEV1/FVC)% is 70% or more. Generally speaking, a low (FEV1/FEV)% (less tlian 70%) indicates an "obstructive" impainnent to exhaling rapidly, and a tow FVC (less than 80% of predicted) indicates a "restrictive" impainnent oflung opacity. Ifboth FVC and (FEV1/FVC)% are low a "mixed" impainnent (both obstructive and restrictive) is said to be present Sane individuals with moderate or severe obstructive impainnent are not able to empty their lures fully during tlie time forced vital capacity is usually measured (6 seconds). In such cases, the FVC may be below nonnal, indicating a restrictive or mixed impainnent, when, in fact, only an obstructive impainnent exists. Additional pulmonary function tests, not suitable for "field" administration, are needed to characterize accurately tlie type ofabnonnality in such persons. Ihe forced expiratory flow rate during tlie middle half of expiration (Fir!-25-75) ls usually ak) reduced when an obstructive impainnent is present However, since it can vary widely in between nonnal individuals and between different tests in die same individual it is not generally' used to diagnose an impairment on an individual bask In tills .survey', the FEF25-75 was used oily for group comparisons. Various occupational and rwn-occupationa] conditions can aflect the results ofpulmonary function tests. Cigarette-related bronchitis and emphysema are probably tlie most common causes ofa low FEV 1 /FVC ar nong the general working population, although certain occupational chemical and dust exposures can also cause or contribute to it A low FVC Is more suggestive ofthe effects ofoccupational exposures such as crystalline silica, asbestos, and hard metal dust Abnormal test results, by themselves, should be intopreted wily as an indicator ofimpaired lung function, not as diagnoses ofspecific diseases. Furtliennore. tliey should not necessarily be interpreted in any individual case as being due to either occupational exposures in general or specific exposures at Farr Wheel Drive. Iks ctemiinafion can only be made after a more conplete medical evaluation than NIOSH provides. HWBUI0007331 APPENDIX B Explanation ofPrevalence Ratios and Smoking-Adjusted Prevalence Ratios A prevalence ratio was calculated by dividing She prevalence ofa symptom (proportion ofpersons reportin'' that symptom) among welders by the prevalence ofa symptom in controls. A prevalence ratio of 1.0 means that the same proportion ofwelders and controls repotted the synptorn; a prevalence ratio ofgreaterthan 1.0 means that higher proportion ofwelders reported the symptom; a prevalence ratio ofless than 1.0 means that fewer welders than controls reported a symptom. To estimate a single prevalence ratio comparing all welders to all controls while accounting forte influence ofcurrent smoking, we computed a "smoking-adjusted prevalence ratioThis is a weighted average ofthe prevalence ratios for smokers and non-smokers, but has the same interpretation as the prevalence ratio for each smoking category (Le., prevalence ratio greaterthan 1.0 means a symptom is more prevalent in welders). The smoking-adjusted prevalence ratio was computed using te "Mantel Hanzel estimate1'1, which refers to a specific method of statistical adjustment For each smoking-adjusted prevalence ratio, we computed a 95% confidence interval which reflects te lower and upper limits ofpossible values ofte "trie" prevalence ratio (te prevalence ratio that would be obtained from averaging the results ofa large number of studies ofwelders and controls under te same conditions as in this study) that the data we collected would be consistent with. We used a statistical technique called te "test-based" method to compute tliese confidence intervals A property ofthese confidence intervals is that ifte value 1.0 Erlls within a given confidence interval, te corresponding prevalence ratio estimate is not "statistically significantly" different from 1.0. For example; ifte prevalence ratio estimate fora symptom is 1.8 and the 95% confidence interval is (0.8 - 4.1 % welders in the study population were more likely (1.8 times more likely) to report tint symptom. However, te difference between welders and controls could have occurred by chance 5% or more ofthe time even if, on the average, welders and controls have the same prevalence ofsymptoms. If cm te other hand, te 95% (confidence interval for a prevalence ratio does not include 1.0,te corresponding estimate ofthe prevalence ratio is "statistically significantly" different from 1.0. For example, ifte prevalence ratio estimate for a given synptorn is 6.4 and te 95% confidence interval is (1.7 23.9), welders were 6.4 time mere likely to report tint symptom than controls. Such a Large prevalence ratio would be expected, by chance, less than 5% ofthe time, ifthe "true" prevalence ratio were 1.0. HWBUI0007332 APPENDIX C Computation ofSpirometry Test Residuals5 (Observed minus Predicted) Spirometry results were adjusted for height and ays as folbws: Using an equation derived from a study ofheahhy, non-smoking individuals 3) (see below'), the value ofeach lung function parameter measured which would be expected, based on a subject's height and age was computed. This "predicted" value was subtracted from the value ofthe parameter "observed" (Le, actually measured) in to individual. The result was tlie "residual" value for that lung function parameter. Forexanple, ifa given subject's FEV1 was 236 liters and the FEV1 expected based on his height and age was 3.08 liters, then his residual FEV1 would be -0.72 liters. In this case the subject's FEV1 is less then the average expected A positive residual FEV1 indicates the FEV 1 is greater tlian expected The residual values forFEVl, FVC, FEF 25-75 and (FEV1/FVC)% were used in subsequent analysis. Equations used to compute predicted values for spirometry: Males, greater than or equal to 25 years ofage: Predicted: FEV 1 (liters) = 4203 + 0.052 * freight (cm) - 0.027 * age (yrs) FVC (liters) = -5.459 + 0.065 * height - 0.029 * age FEF 25-75 (liters per second) = -1.864 + 0.045 * height -0.031 * age (FEV 1 /FVC)% = 103.64 - 0.087 * freight -0.140* age Males, less than 25 years ofage: Predicated FEV 1 (liters) = 4.808 + 0.046 * height + 0.045 * age FVC (liters) = -5.508 + 0.050 * Height + 0.078 * age20 FEF 25-75 (liters) = -5334 + 0.059 * height (FEV1/FVC)%= 103.64-0.087 * height-0.140 * age HWBUI0007333