The environmental etiology of neurodegenerative disorders is of great research interest and pesticides have received special scrutiny because of their pervasive use in modem agriculture. The HAAS is a cohort of 8,006 Japanese-American men for whom extensive lifestyle, work, and health records have been collected since the late 1960s. Collection at autopsy of unfixed brain material from a subset of this group allows the measurement of brain levels of persistent chemicals in this cohort. Records from the Department of Agriculture were used to select compounds with specific agricultural/industrial uses in Hawaii. Organochlorines have been used extensively in Hawaii since the 1940s (e.g., DDT) and by the 1960s 4 of the most commonly used on plantations were chlordane, DDT, heptachlor, and lindane (SHC gamma). A capillary GC method with electron capture capable of detection in the parts per billion (PPB) range will be used to assay 80 mg of brain cortex from approximately 200 men for these 4 organochlorines as well as DDT and its metabolite DDE, oxychlordane, trans-nonachlor, dieldrin, BHC (alpha & beta), HCB, endrin, methoxychlor and mirex among others. A pilot evaluation of 15 men with an extensive history of plantation work found measurable levels of compounds with specific agricultural/industrial use (e.g., dieldrin, methoxychlor, trans-nonacblor) as well as compounds with more general usage (e.g., DDE, oxychlordane, g-chlordane). Levels ranged from 1.8 - 13.24, 2.13 - 26.05, 1.62 - 7.9, 2.66 - 93.66, 2.11 - 10.3, 4.17 - 12.38, PPB for dieldrin, methoxychlor, trans-nonachlor, DDE, oxychlordane and g-chlordane, respectively. These compounds deposit in lipids and the percentage of lipids in the brain tissue analyzed ranged from 1.8 - .7.1 % of the tissue weight (24 - 104 mg). The lowest quantifiable limit or the lowest, level of compound that can be detected with confidence by the method of analysis is 1.56 PPB for all compounds except methoxychlor for which the limit is 7.81 PPB. Analysis of brain tissue from the HAAS allows for determination of the relations between persistent chemicals in brain and degenerative disorders such as Parkinson's and Alzheimer's diseases.
Neurotoxicology. Emerging Issues in Neurotoxicology Little Rock, AR, USA, 18 - 21 November 2002