RT Journal Article
SR Electronic
T1 Retrospective exposure assessment for a cohort study into respiratory effects of acid anhydrides.
JF Occupational and Environmental Medicine
JO Occup Environ Med
FD BMJ Publishing Group Ltd
SP 692
OP 696
DO 10.1136/oem.55.10.692
VO 55
IS 10
A1 M J van Tongeren
A1 R D Barker
A1 K Gardiner
A1 J M Harris
A1 K M Venables
A1 J M Harrington
A1 A J Newman Taylor
YR 1998
UL http://oem.bmj.com/content/55/10/692.abstract
AB OBJECTIVES: To estimate past exposure to phthalic (PA), trimellitic (TMA) and maleic anhydride (MA) in three alkyd resin and one cushioned flooring factory to estimate exposure-response relations in a retrospective cohort study. METHODS: Personal exposure measurements were carried out in 1992 and quantitative and qualitative information on past exposure and production processes were collected. Job titles were ranked by decreasing exposure and amalgamated into job categories and exposure groups. Multiplication factors for back calculating past exposure levels were estimated with past exposure data, or if no such data were available these factors were estimated by a panel of occupational hygienists. Exposure levels were back calculated starting with the exposure levels in 1992. RESULTS: High exposures to PA were estimated to have occurred among workers operating the PA melting pots in factory 1 (estimated exposure in 1960-9 was 2480 micrograms.m-3). Highest concentrations of TMA were estimated to have occurred among the ink mixers in factory 2 from 1979 to 1986 (554 micrograms.m-3). Exposure in most other job titles was thought to be fairly constant over time for PA, TMA, and MA. CONCLUSIONS: Exposure to acid anhydride at these factories has fallen during the period covered by the study. However, it is estimated that in only one job in factory 2 did past exposure to acid anhydride exceed the current occupational exposure standard. Accuracy of the estimated exposure is limited by a paucity of reliable past exposure data.