NIOSH 2,3,7,8-tetrachlorodibenzo-p-dioxin exposure matrix.
Organohalogen Compounds. Dioxin '97: 17th International Symposium on Chlorinated Dioxins and Related Compounds, Indianapolis, Indiana, August 25-29, 1997. Volume 3: Toxaphene Transport and Fate Ecotoxicology Human Exposure. Hites RA, ed., Bloomington, IN: Symposium Secretariat, DIOXIN '97, 1997 Aug; 33:510-514
In the 1980's the National Institute for Occupational Safety and Health (NIOSH) constructed a 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) Registry of 5,172 workers from 12 U.S. plants with exposure to TCDD, In 1991, NIOSH investigators published a cohort mortality study of these workers which used duration in TCDD-contaminated processes as a surrogate for TCDD exposure. The NIOSH TCDD, Exposure Matrix was constructed to permit additional analyses using estimated TCDD exposure levels. The matrix was constructed for the years 1942-1984 for a sub-cohort of 3,661 workers at 9 plants with sufficient data to characterize level of exposure. A TCDD exposure score was estimated for each job title for each day which a worker was assigned to a TCDD contaminated process. The daily TCDD exposure score was the product of 1) the concentration of TCDD (microg/g) present in process materials, 2) the fraction of the work day exposed to TCDD contamination, and 3) a qualitative factor to account for the extent of worker contact with TCDD. The sum of the daily exposure scores constituted an individual's cumulative occupational exposure score. These exposure scores have no direct interpretation such as micrograms per gram-days. Rather, the cumulative TCDD exposure scores permit the relative ranking of workers in the cohort by intensity of exposure. The daily TCDD exposure scores ranged from 0.001 to 1,250.
Exposure-levels; Exposure-assessment; Information-systems; Dioxins; Analytical-processes
David A. Marlow, National Institute For Occupational Safety and Health 4676 Columbia Parkway, Cincinnati, Ohio 45226 USA
Organohalogen Compounds. Dioxin '97: 17th International Symposium on Chlorinated Dioxins and Related Compounds, Indianapolis, Indiana, August 25-29, 1997. Volume 3: Toxaphene Transport and Fate Ecotoxicology Human Exposure