APPLICATION OF AN EVENT MARKER IN THE OCCUPATIONAL EPIDEMIOLOGIC-STUDY OF ACUTE IRRITANT SYMPTOMS

Field studies of occupational exposure to airborne irritants have pred ominantly relied on symptom surveys of study participants. As part of a new approach to the study of acute irritant symptoms, subjects expos ed to sodium borate dusts recorded their symptom responses at hourly i nterviews as well as instantaneously on an electronic device called an event marker. Overall, the unprompted marks indicated fewer irritant events than the interviews. Marks were more frequent in the presence o f more than one type of symptom and also appeared to reflect more seve re symptoms. A proportion of the marked events occurred in time interv als when no symptoms were recalled during the interview. The exposure- response relations were similar regardless of whether they were based on the interview reports or the electronically marked symptoms. The ev ent marker provided a means to examine the time of onset of the acute symptom event. It also made it possible to examine directly the timing profiles of symptom response in relation to changes in exposure level s in a field setting. Despite some inconsistencies, the finding sugges ts that the event marker may provide an alternative to frequent interv iews of exposed workers to obtain irritant symptom responses for expos ure-response modeling.