EXPOSURE-RESPONSE RELATIONSHIPS IN THE FORMATION OF SPECIFIC ANTIBODIES TO HEXAHYDROPHTHALIC ANHYDRIDE IN EXPOSED WORKERS

OBJECTIVES - Exposure-response relationships in the formation of speci fic antibodies to hexahydrophthalic anhydride (HHPA) was studied in ex posed workers. METHODS - The relation between exposure to HHPA and the levels of specific immunoglobin E [(radioallergosorbent test (RAST)] and immunoglobin G (enzyme-linked immunosorbent assay) antibodies was investigated in a cross-sectional study on 95 workers from two plants using epoxy resin with HHPA as a hardener; the mean time of exposure w as 7 (range 0.1-25) years. RESULTS - The specific immunoglobin E and i mmunoglobin G was significantly increased in exposed workers when they were compared with unexposed workers or external referents. There was no significant difference in the number of RAST positives [N = 23 (24 %)] between the groups of workers exposed to <10 mu g.m(-3), 10-<50 mu g.m(-3), or greater than or equal to 50 mu g.m(-3). No effects were f ound of atopy or smoking habits on the prevalence of RAST positives. F ive out of seven workers positive for immunoglobulin E in the group wi th the lowest exposures reported frequent short-time (minutes per day) exposures exceeding 50 mu g.m(-3). A correlation was seen between spe cific immunoglobulin E and G antibodies (r(s)=0.5). CONCLUSIONS - The results indicate that HHPA is a sensitizing compound even at low expos ure levels and that short-time peak exposures may have an impact on im munoglobulin E sensitization.