Instrumental neutron activation analysis was used to determine the elemental concentrations in water and air solid samples
collected on Nuclepore and Whatman filters from the Walker Branch Watershed. The results from this study show that the trace
element concentrations removed by water from the watershed vary seasonally, as well as geographically. The data point up the
usefulness and versatility of absolute neutron activation analysis. The NBS Standard Orchard Leaves was assayed in a similar
manner, and good agreement was obtained between results here and standard values.