Little is known about the relationship between perceived and objective measures of the built environment and physical activity behavior among rural populations. Within the context of a lifestyle-change intervention trial for rural women, Strong Hearts, Healthy Communities (SHHC), we examined: (1) if Walk Score (WS), an objective built environment measure, was associated with perceived built environment (PBE); (2) if WS and PBE were associated with moderate-to-vigorous physical activity (MVPA); and (3) if MVPA changes were modified by WS and/or PBE. Accelerometers and questionnaires were used to collect MVPA and PBE. Bivariate analyses and linear mixed models were used for statistical analyses. We found that WS was positively associated with perceived proximity to destinations (p < 0.001) and street shoulder availability (p = 0.001). MVPA was generally not associated with WS or PBE. Compared to controls, intervention group participants increased MVPA if they lived in communities with the lowest WS (WS = 0), fewer perceived walkable destinations, or extremely safe perceived traffic (all p < 0.05). Findings suggest that WS appears to be a relevant indicator of walkable amenities in rural towns; results also suggest that the SHHC intervention likely helped rural women with the greatest dearth of built environment assets to improve MVPA.

Understanding interactions between iron (oxyhydr)oxide nanoparticles and plutonium is essential to underpin technology to treat radioactive effluents, in cleanup of land contaminated with radionuclides, and to ensure the safe disposal of radioactive wastes. These interactions include a range of adsorption, precipitation, and incorporation processes. Here, we explore the mechanisms of plutonium sequestration during ferrihydrite precipitation from an acidic solution. The initial 1 M HNO3 solution with Fe(III)(aq) and 242Pu(IV)(aq) underwent controlled hydrolysis via the addition of NaOH to pH 9. The majority of Fe(III)(aq) and Pu(IV)(aq) was removed from solution between pH 2 and 3 during ferrihydrite formation. Analysis of Pu-ferrihydrite by extended X-ray absorption fine structure (EXAFS) spectroscopy showed that Pu(IV) formed an inner-sphere tetradentate complex on the ferrihydrite surface, with minor amounts of PuO2 present. Best fits to the EXAFS data collected from Pu-ferrihydrite samples aged for 2 and 6 months showed no statistically significant change in the Pu(IV)-Fe oxyhydroxide surface complex despite the ferrihydrite undergoing extensive recrystallization to hematite. This suggests the Pu remains strongly sorbed to the iron (oxyhydr)oxide surface and could be retained over extended time periods.