| 1. |
- Nielsen, Jörn, et al.
(author)
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Allergy to methyltetrahydrophthalic anhydride in epoxy resin workers
- 1992
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In: British Journal of Industrial Medicine. ; 49:11, s. 769-775
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Journal article (peer-reviewed)abstract
- One hundred and forty four current and 26 former workers in a plant producing barrels for rocket guns from an epoxy resin containing methyltetrahydrophthalic anhydride (MTHPA; time weighted average air concentration up to 150 uglm') were studied. They showed higher frequencies of work related symptoms from the eyes (31 v 0%; p < 0-001), nose (53 v 9%; p < 0-001), pharynx (26 v 6%; p < 0-01), and asthma (11 v 0%; p < 0 05) than 33 controls. Also they had higher rates of positive skin prick test to a conjugate of MTHPA and human serum albumin (16 v 0%; p < 0-01), and more had specific IgE and IgG serum antibodies (18 v 0%; p < 0-01 and 12 v 0%; p < 0 05 respectively). There were statistically significant exposure-response relations between exposure and symptoms from eyes and upper airways, dry cough, positive skin prick test, and specific IgE and IgG antibodies. There was a non-significant difference in reaction to metacholine between exposed workers and non-smoking controls. In workers with and without specific IgE antibodies, differences existed in frequency of nasal secretion (54 v 23%; p < 0-05) and dry cough (38 v 12%; p < 0-05). Workers with specific IgG had more dry cough (38 v 12%; p < 0-05), but less symptoms ofnon-specific bronchial hyperreactivity (0 v 26%; p < 0-05). Atopic workers sneezed more than non-atopic workers (65 v 30%; p < 0-01). In a prospective study five sensitised workers who left the factory became less reactive to metacholine, and became symptom free. In 41 workers who stayed, there was no improvement, despite a 10-fold reduction in exposure. The results show the extreme sensitising properties ofMTHPA.
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| 2. |
- Welinder, Hans, et al.
(author)
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Exposure-response relationships in the formation of specific antibodies to hexahydrophthalic anhydride in exposed workers
- 1994
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In: Scandinavian Journal of Work, Environment and Health. - 0355-3140. ; 20:6, s. 459-465
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Journal article (peer-reviewed)abstract
- OBJECTIVES--Exposure-response relationships in the formation of specific antibodies to hexahydrophthalic anhydride (HHPA) was studied in exposed 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 was 7 (range 0.1-25) years. RESULTS--The specific immunoglobin E and immunoglobin 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 micrograms.m-3, 10--< 50 micrograms.m-3, or > or = 50 micrograms.m-3. No effects were found of atopy or smoking habits on the prevalence of RAST positives. Five out of seven workers positive for immunoglobulin E in the group with the lowest exposures reported frequent short-time (minutes per day) exposures exceeding 50 micrograms.m-3. A correlation was seen between specific immunoglobulin E and G antibodies (rs = 0.5). CONCLUSIONS--The results indicate that HHPA is a sensitizing compound even at low exposure levels and that short-time peak exposures may have an impact on immunoglobulin E sensitization.
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