BACKGROUND: A job exposure matrix was developed to estimate the 2,3, 7,8-tetrachlorodibenzo-p-dioxin exposure of 3,538 workers who produced 2,4,5-trichlorophenol and its derivatives. METHODS: Daily TCDD exposure scores that were plant, process, and period specific were estimated for each job title as the product of 1) the concentration of TCDD (microg/g); 2) a qualitative factor to account for the extent of worker contact and 3) time exposed to TCDD contamination. Daily scores were summed to compute individual cumulative TCDD exposure scores. RESULTS: Daily TCDD exposure scores ranged from 0.001 to 1,250. Cumulative TCDD scores ranged from 0.002 to 1,559,430. The 393 workers with records of chloracne in the TCDD exposure cohort (11%) had markedly higher cumulative scores than those with no record of chloracne (a median score of 11,546 vs. 77). CONCLUSIONS: The cumulative TCDD exposure scores incorporate both duration and level of exposure, and permit the relative ranking of worker exposures for the evaluation of exposure-response relationships between TCDD exposure and mortality in an updated cohort study analysis. Copyright Published 2000 Wiley-Liss, Inc.
BACKGROUND: A job exposure matrix was developed to estimate the 2,3, 7,8-tetrachlorodibenzo-p-dioxin exposure of 3,538 workers who produced 2,4,5-trichlorophenol and its derivatives. METHODS: Daily TCDD exposure scores that were plant, process, and period specific were estimated for each job title as the product of 1) the concentration of TCDD (microg/g); 2) a qualitative factor to account for the extent of worker contact and 3) time exposed to TCDD contamination. Daily scores were summed to compute individual cumulative TCDD exposure scores. RESULTS: Daily TCDD exposure scores ranged from 0.001 to 1,250. Cumulative TCDD scores ranged from 0.002 to 1,559,430. The 393 workers with records of chloracne in the TCDD exposure cohort (11%) had markedly higher cumulative scores than those with no record of chloracne (a median score of 11,546 vs. 77). CONCLUSIONS: The cumulative TCDD exposure scores incorporate both duration and level of exposure, and permit the relative ranking of worker exposures for the evaluation of exposure-response relationships between TCDD exposure and mortality in an updated cohort study analysis. Copyright Published 2000 Wiley-Liss, Inc.
Authors: Elizabeth M Ward; Paul A Schulte; Steve Bayard; Aaron Blair; Paul Brandt-Rauf; Mary Ann Butler; David Dankovic; Ann F Hubbs; Carol Jones; Myra Karstadt; Gregory L Kedderis; Ronald Melnick; Carrie A Redlich; Nathaniel Rothman; Russell E Savage; Michael Sprinker; Mark Toraason; Ainsley Weston; Andrew F Olshan; Patricia Stewart; Sheila Hoar Zahm Journal: Environ Health Perspect Date: 2003-01 Impact factor: 9.031