Effects of Land Use on the Spatial and Vertical Distribution of Arsenic in Soil Cores on Oahu
Effects of Land Use on the Spatial and Vertical Distribution of Arsenic in Soil Cores on Oahu
| dc.contributor.advisor | De Carlo, Eric | |
| dc.contributor.author | Thomas, Sara | |
| dc.contributor.department | Oceanography | |
| dc.contributor.department | Global Environmental Science | |
| dc.date.accessioned | 2020-08-18T23:59:36Z | |
| dc.date.available | 2020-08-18T23:59:36Z | |
| dc.date.issued | 2009 | |
| dc.description.course | OCN 499 - Undergraduate Thesis | |
| dc.identifier.uri | http://hdl.handle.net/10125/69399 | |
| dc.publisher.place | Honolulu | |
| dc.subject | soil | |
| dc.subject | chemistry | |
| dc.title | Effects of Land Use on the Spatial and Vertical Distribution of Arsenic in Soil Cores on Oahu | |
| dc.type | Thesis | |
| dcterms.abstract | Soil cores were analyzed using Inductively Coupled Plasma Mass Spectrometry (ICP-MS) to determine the effects of land use on spatial and vertical distribution of arsenic (As) in soils around the island of O’ahu, Hawai’i. Six cores were collected and divided into 10 cm increments at five locations. Two cores were obtained from a gardenia farm (WK1 and WK3) and one in a forested region of Manoa Valley (WK2), one from the Lyon Arboretum (LA), and two from fallow pineapple and sugarcane fields in Kunia (KU) and Waipahu (WAI), respectively. Concentrations of As were above 500 ppm in all three of the cores taken along the Waikeakua Stream in Manoa. The concentrations are consistent with the hypothesis that As is introduced to soils through anthropogenic activity, either the application of superphosphate fertilizers or pesticides. High concentrations in the forested area suggest prior human activity in Manoa Valley has left soils with elevated concentrations of As. Relatively low, yet still elevated over natural, concentrations of As measured in the WAI core suggest alternative methods of pest and weed control were applied to sugarcane crops in this field. Both the LA and KU core demonstrated concentrations of As similar to Hawaiian background levels. In cores with As contamination, concentrations decrease as a function of depth but maximum concentrations in the soil column occur at 10-20 cm depth. Drastic decreases in concentrations of As below this depth may be due to the strong affinity of As to iron oxides (FeOx) in soils at the surface where As is introduced through anthropogenic activity. Tilling of surface soils or the uptake of As from surface soils by plants may account for the observed subsurface peak in concentration of As. | |
| dcterms.extent | 65 pages | |
| dcterms.language | English | |
| dcterms.publisher | University of Hawaiʻi at Mānoa | |
| dcterms.rights | All UHM dissertations and theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission from the copyright owner. | |
| dcterms.rightsholder | Thomas, Sara | |
| dcterms.type | Text |
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