PH05 Fate and Effects of Energetic Compounds
Exhibit Hall
8:00 AM - Thursday
(PH028) Rapid assessment of plant responses to explosive materials in groundwater.
Winfield, L.1, Davis, J.1, Wade, R.1, Inouye, L.1, Ragan, D.2, Graham, T.2, 1 US Engineer research and Developmental Center, Vicksburg, MS, USA2 Contractor, US Army Engineer Research and Development Center, Vicksburg, MS, USA
ABSTRACT- Groundwater contaminated with explosive materials is a potential problem at sites where they are manufactured, utilized, or disposed. Rapid screening bioassays using plants sensitive to explosives would be useful for evaluating the efficacy of groundwater remediation activities. A plant bioassay developed to assess terrestrial plant responses to RDX and HMX was modified for use with groundwater samples. Sunflower plants were previously identified as sensitive to explosive materials. They were used during the preliminary assessments of groundwater samples from 23 wells contaminated with RDX_CR__LF_(< 310 ppb), HMX (< 49 ppb), MNX (< 2.3 ppb), and 3-4, DNT (< 5.1 ppb). A completely randomized experimental design (5-replicates per treatment) was used. The plants were germinated and grown for either 5-days or 2-weeks in the groundwater using Ottawa sand as the support media. Growth (biomass, plant height, root length), adverse developmental effects (abnormal morphology, early senescence, atypical pigmentation, etc.), and physiological responses (chlorophyll and carotenoid concentrations) were assessed. Statistically significant differences between control and treatment means were observed in the physiological responses and developmental effects, but not in growth responses. The significant differences were measured in the chlorophyll and carotenoid concentrations, while adverse developmental effects were observed in plant leaves, stems, and roots. The 2-week exposure was determined to be the optimum exposure duration and will be used during future remediation activities. The bioassay was not designed to determine which explosive in the mixture caused the adverse impacts, however exposure to several of the groundwater samples elicited similar physiological responses._CR__LF_
Key words: explosives, groundwater, plants, bioassay