RESPIRATORY-DISEASE IN WORKERS EXPOSED TO COLOPHONY SOLDER FLUX FUMES- CONTINUING HEALTH CONCERNS

The objectives of this study were to establish the prevalence of respi ratory, eye, nose and throat symptoms of likely work-relation in worke rs exposed to colophony solder flux fumes and to assess their lung fun ction. A cross-sectional study was conducted in four medium-sized elec tronics firms in which control measures to capture solder flux fume we re absent or visibly ineffective. All female solderers and women worki ng adjacent to soldering stations completed an administered questionna ire concerning symptoms, work history and current soldering frequency. Measurements were made of their forced vital capacity (FVC) and force d expiratory volume in one second (FEV1) during the course of a workin g shift, using a Vitallograph-Compact portable spirometer. Using weekl y hours of soldering as a crude index of current exposure, workers wer e classified into high (greater than or equal to 37 h/wk) and low (les s than or equal to 20 h/wk) exposure groups, and their health response s were compared in the analysis. Individuals with symptoms suggestive of work-related asthma were also asked to provide serial peak flow mea surements over a further 2-week period, and adequate returns were char ted and read by two physicians experienced in the diagnosis of occupat ional asthma. Data were collected on 152 female workers (overall parti cipation rate = 97%). Symptoms of recurrent, persistent wheeze and/or chest tightness were reported by 75 (49%) of interviewees; 36 (24%) ga ve a history typical of occupational asthma and six more (4%) a histor y of pre-existing asthma worsened at work. Twenty-one (14%) of the wor kforce complained of recurrent breathlessness on moderate exertion; 41 workers (27%) had work-related symptoms of the nose or throat and 25 (16%) had work-related eye symptoms. The odds ratios for 'all wheeze', shortness of breath, and work-related eye, nose and chest symptoms we re all significantly greater (raised about 4-5 fold) in women who sold ered greater than or equal to 37 h/wk when compared with those solderi ng less than or equal to 20 h/wk. After adjustment by logistic regress ion for atopy, age and smoking status even higher risk estimates were generally obtained. The odds ratios (OR) and 95% confidence intervals (CI) for high vs. low were, for 'all wheeze', OR = 7.2, CI = 2.5-20.7; for work related eye symptoms, OR = 5.2, CI: = 1.4-19.8; for work-rel ated nasal symptoms, OR = 4.0, CI = 1.4-11.1 and for occupational asth ma symptoms, OR = 5.2, CI = 1.4-14.2. Mean FEV, and NC percentage diff erence from expected were slightly lower in full-time solderers than i n pari-time solderers, but the differences were not significant. Thirt y-seven of the 51 workers (73%) who were asked to carry out serial pea k flow measurements completed an adequate return: 27 of these records confirmed the presence of asthma, and in all of the cases the history suggested onset post-dating employment in soldering. Eleven peak flow records were indicative of occupational asthma. The health problems as sociated with colophony solder flux were documented over 18 years ago, but are still clearly apparent in situations where adequate control h as not been achieved.