Pulmonary function abnormalities and airway irritation symptoms of metal fumes exposure on automobile spot welders.
BACKGROUND
Spot or resistance welding has been considered less hazardous than other types of welding. Automobile manufacturing is a major industry in Taiwan. Spot and arc welding are common processes in this industry. The respiratory effects on automobile spot welders exposed to metal fumes are investigated.


METHODS
The cohort consisted of 41 male auto-body spot welders, 76 male arc welders, 71 male office workers, and 59 assemblers without welding exposure. Inductivity Coupled Plasma Mass Spectrophotometer (ICP-MS) was applied to detect metals' (zinc, copper, nickel) levels in the post-shift urine samples. Demographic data, work history, smoking status, and respiratory tract irritation symptoms were gathered by a standard self-administered questionnaire. Pulmonary function tests were also performed.


RESULTS
There were significantly higher values for average urine metals' (zinc, copper, nickel) levels in spot welders and arc welders than in the non-welding controls. There were 4 out of 23 (17.4%) abnormal forced vital capacity (FVC) among the high-exposed spot welders, 2 out of 18 (11.1%) among the low-exposed spot welders, and 6 out of 130 (4.6%) non-welding-exposed workers. There was a significant linear trend between spot welding exposure and the prevalence of restrictive airway abnormalities (P = 0.036) after adjusting for other factors. There were 9 out of 23 (39.1%) abnormal peak expiratory flow rate (PEFR) among high-exposed spot welders, 5 out of 18 (27.8%) among the low-exposed spot welders, and 28 out of 130 (21.5%) non-welding-exposed workers. There was a borderline significant linear trend between spot welding exposure and the prevalence of obstructive lung function abnormalities (P = 0.084) after adjusting for other factors. There was also a significant dose-response relationship of airway irritation symptoms (cough, phlegm, chronic bronchitis) among the spot welders. Arc welders with high exposure status also had a significant risk of obstructive lung abnormalities (PEFR reduction). There was also a significant dose-response relationship of airway irritation symptoms (cough, phlegm, chest tightness, and chronic bronchitis) among the arc welders.


CONCLUSIONS
These findings suggest that restrictive and obstructive lung abnormalities, and airway irritation symptoms are associated with spot and arc welding exposures.
Luo
Jiin-Chyuan John
JC
Department of Public Health, Chang Gung University, Tao-Yuan, Taiwan, Republic of China. Luo5485@giga.net.tw
Hsu
Kuang-Hung
KH
Shen
Wu-Shiun
WS
D000328:Adult; D000395:Air Pollutants, Occupational / Q000633:toxicity*; D001336:Automobiles; D029481:Bronchitis, Chronic / Q000139:chemically induced*; D016022:Case-Control Studies; D015331:Cohort Studies; D003371:Cough / Q000139:chemically induced*; D006801:Humans; D008173:Lung Diseases, Obstructive / Q000139:chemically induced*; D008297:Male; D019216:Metals, Heavy / Q000633:toxicity* / Q000652:urine; D009784:Occupational Diseases / Q000139:chemically induced; D016273:Occupational Exposure / Q000009:adverse effects; D012129:Respiratory Function Tests; D012907:Smoking / Q000009:adverse effects; D013624:Taiwan; D014896:Welding
D000395:Air Pollutants, Occupational; D019216:Metals, Heavy