T8 AM Ecological Fate and Effects of Explosives and Related Compounds
Tuesday, 15 November 2005: 8:00 AM - 11:40 AM in 337-338

(SAM-1117-816958) Development of soil-to-plant tissue bioaccumulation models for energetic compounds and metabolites.

Sample, B.E.¹, Tsao, C.L.¹, Johnson, M.S.², ¹ CH2M HILL, Sacramento, CA, USA² US Army Center for Health Promotion and Preventive Medicine, Aberdeen Proving Ground, MD, USA

ABSTRACT- Concentrations of contaminants in tissue are needed to estimate exposure of birds and mammals. In the absence of measured data, models are used. Empirical models based on measured relationships are better than models based on chemical characteristics (i.e., Kow). We developed soil-to-plant tissue bioaccumulation models for 10 energetic compounds [HMX, perchlorate, RDX, tetryl, TNB, TNT, and its metabolites (2-ADNT, 4-ADNT, 2,4-DNT, and 2,6-DNT] representing 4 plant tissue types (leaf, root, fruit, and seed). These models were based on data from journal papers and the gray literature. The studies were pooled by chemical and tissues to determine whether linear relationships between chemical concentrations in soil and in plant tissues existed. Six chemicals (2-ADNT, 2,6-DNT, HMX, RDX, and TNT) had significant log-linear relationships between soil to at least one plant tissue compartment; inversely proportional relationship were found for TNT and 4-ADNT in soil to plant root. For the remaining chemical-to-tissue combinations, summary statistics of BAFs (ratio of soil to tissue) were generated.. Only 2,4-DNT and 4-ADNT had median soil-to-plant foliage BAFs of less than one; the remaining chemicals (2,6-DNT, 2-ADNT, HMX, perchlorate, RDX, tetryl, TNB, TNT and its metabolites) all had median foliage uptake values greater than one. Three chemicals had soil-to fruit uptake values (RDX, tetryl, and TNT). RDX is the only chemical that had a median uptake value of soil-to-fruit greater than one. For soil-to-root uptake values, RDX, tetryl, and TNT had median uptake values greater than one. Among the four chemical uptake data from soil-to-seed (perchlorate, RDX, tetryl, and TNT), only RDX had median uptake value greater than one.

Key words: explosives, exposure, bioaccumulation model, plant uptake