Symptoms, lung function, and diurnal variation in peak expiratory flow rate among female solderers in the electronics industry.

The purpose was to determine if solderers had increased diurnal variation (DV) in peak expiratory flow rate (PEFR) and chronic impairment of lung function. A cross-sectional study of 150 female operators doing manual soldering using flux-cored (rosin-based) solder wire and 52 administrative staff from two electronics factories was carried out. They answered a questionnaire, had their forced expiratory volume in 1 sec (FEV1) and forced vital capacity (FVC) measured and their 3-hourly PEFR monitored for 5 working days. The DV in PEFR was the difference in the daily maximum and minimum PEFR expressed as a percentage of the maximum. Six solderers with smoking history were excluded from the analysis. Solderers had a significantly higher prevalence of work-related eye (14.6%) and nose (10.4%) irritation. The prevalence of cough, breathlessness, and wheezing was low. There was no overt case of occupational asthma. The DV in PEFR of 6.0% was not increased. The analysis of FEV1 and FVC was restricted to Chinese only (101 solderers and 51 controls): these were not significantly different. Solderers with 5 or more years of exposure had a significantly lower FEV1/FVC (%) of 88.4% after adjustment for age. In conclusion, solderers with 5 or more years of exposure may have a mild obstructive effect apart from smoking, asthma, or age.