Uptake and fate of hexahydro-1,3,5-trinitro-1,3,5-triazine by Chrysopogon zizanioides

Hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) is a nitramine compound that has been used heavily by the military as an explosive. Manufacturing, use, and disposal of RDX have led to several contamination sites across the United States. RDX is both persistent in the environment and a threat to human health, making its remediation vital. The use of plants to extract RDX from the soil and metabolize it once it is in the plant tissue, is being considered as a possible solution. In the present study, the tropical grass Chrysopogon zizanioides was grown hydroponically in the presence RDX at 3 different concentration levels: 0.3, 1.1, and 2.26 ppm. The uptake of RDX was quantified by high performance liquid chromatography (HPLC) analysis of media samples taken every 6 hr during the first 24 hr and then daily over a 30-day experimental period. A rapid decrease in RDX concentration in the media of both controls and plant treatments was seen within the first 18 hours of the experiment with the greatest loss in RDX over time occurring within the first 6 hours of exposure. The loss was similar in both controls and plant exposures and possibly attributed to rapid uptake by the containers. A plant from one treatment at each of the three concentrations was harvested at Day 10, 20 and 30 throughout the experiment and extracted to determine the localization of RDX within the tissue and potentially identify any metabolites on the basis of differing retention times. Of the treatments containing 0.3, 1.1, and 2.26 ppm RDX, 13.1%, 18.3%, and 24.2% respectively, was quantified in vetiver extracts, with the majority of the RDX being localized to the roots. All plants not yet harvested were harvested on Day 30 of the experiment. A total of three plants exposed to each concentration level as well as the control, were extracted and analyzed with HPLC to determine amount of RDX taken up, localization of RDX within the plant tissue, and potentially identify any metabolites. Phytotoxicity of RDX to vetiver was also monitored. While a loss in biomass was observed in plants exposed to all the different concentrations of RDX, control plants grown in media not exposed to RDX showed the greatest biomass loss of all the treatments. There was also little variation in chlorophyll content between the different concentration treatments with RDX. This preliminary greenhouse study of RDX uptake 10 by Chrysopogon zizanioides will help indicate the potential ability of vetiver to serve as a plant system in the phytoremediation of RDX.

Adapting health-risk communication to the specific cultural contexts of diverse populations : an assessment of malaria-treatment programs in Liberia

Drawing on theories of technical communication, rhetoric, literacy, language and culture, and medical anthropology, this dissertation explores how local culture and traditions can be incorporated into health-risk-communication-program design and implementation, including the design and dissemination of health-risk messages. In a modern world with increasing global economic partnerships, mounting health and environmental risks, and cross-cultural collaborations, those who interact with people of different cultures have “a moral obligation to take those cultures seriously, including their social organization and values” (Hahn and Inhorn 10). Paradoxically, at the same time as we must carefully adapt health, safety, and environmental-risk messages to diverse cultures and populations, we must also recognize the increasing extent to which we are all becoming part of one, vast, interrelated global village. This, too, has a significant impact on the ways in which healthcare plans should be designed, communicated, and implemented. Because communicating across diverse cultures requires a system for “bridging the gap between individual differences and negotiating individual realities” (Kim and Gudykunst 50), both administrators and beneficiaries of malaria-treatment-and-control programs (MTCPs) in Liberia were targeted to participate in this study. A total of 105 people participated in this study: 21 MTCP administrators (including designers and implementers) completed survey questionnaires on program design, implementation, and outcomes; and 84 MTCP beneficiaries (e.g., traditional leaders and young adults) were interviewed about their knowledge of malaria and methods for communicating health risks in their tribe or culture. All participants showed a tremendous sense of courage, commitment, resilience, and pragmatism, especially in light of the fact that many of them live and work under dire socioeconomic conditions (e.g., no electricity and poor communication networks). Although many MTCP beneficiaries interviewed for this study had bed nets in their homes, a majority (46.34 percent) used a combination of traditional herbal medicine and Western medicine to treat malaria. MTCP administrators who participated in this study rated the impacts of their programs on reducing malaria in Liberia as moderately successful (61.90 percent) or greatly successful (38.10 percent), and they offered a variety of insights on what they might do differently in the future to incorporate local culture and traditions into program design and implementation. Participating MTCP administrators and beneficiaries differed in their understanding of what “cultural incorporation” meant, but they agreed that using local indigenous languages to communicate health-risk messages was essential for effective health-risk communication. They also suggested that understanding the literacy practices and linguistic cultures of the local people is essential to communicating health risks across diverse cultures and populations.