Distribution and Abundance of Arsenic in the Soils and Sediments of O‘ahu, Hawai‘i

• Published in: Aquatic geochemistry Vol. 20; no. 2-3; pp. 87 - 113
• Main Authors: De Carlo, Eric Heinen, Tomlinson, Michael S, deGelleke, Laura E, Thomas, Sara
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer-Verlag 2014; Springer Netherlands
• Subjects: anthropogenic activities; arsenic; Earth and Environmental Science; Earth Sciences; Geochemistry; Hydrogeology; Hydrology/Water Resources; marine environment; marine sediments; Original Paper; soil depth; stream channels; Water Quality/Water Pollution; Soils; Hawai‘i; O‘ahu; Sediments; Arsenic (As)
• ISSN: 1380-6165; 1573-1421
• DOI: 10.1007/s10498-013-9212-9

Lack of high-spatial-resolution soil and sediment arsenic data for Hawai‘i has generated substantial disagreement between researchers and regulators regarding the magnitude of natural levels of arsenic in Hawai‘i and rendered difficult the defining of areas of anthropogenically elevated arsenic. Our earlier research into the occurrence of arsenic in terrestrial and marine environments revealed widely disparate concentrations of arsenic with no apparent spatial pattern. To better understand the distribution and abundance of arsenic in soils and sediments of O‘ahu, we collected an additional 64 samples at locations chosen to represent different environments with varying degrees of human impact. We found surface arsenic values that ranged from 0.28 to 740 ppm with a median concentration of 8.1 ppm, which is above the global median of 5 ppm and US soil median of 5.2 ppm. Higher concentrations of arsenic (up to 913 ppm) were encountered at depth in soil cores. The median arsenic in streambed sediments from one of our earlier studies of 6.1 ppm was comparable to the conterminous US median of 6.3 ppm; however, we encountered arsenic concentrations as high as 43.9 ppm (median = 8.60 ppm, n = 75) in marine sediments in recent work off the leeward coast of O‘ahu. Overall, arsenic in the soils and sediments of O‘ahu is elevated relative to world and national values, but there still is no readily discernible pattern in the distribution of arsenic to explain these elevated values.