![Anomalous [As] were seen in bed
sediments during USGS NAWQA Study
A = Agriculture
F = Forested
U = Urban
M = Mixed](https://image.slidesharecdn.com/6135159d-c5d2-48dd-b52e-d95bf74f3589-150418162249-conversion-gate02/85/Oahu-Soil-Sediment-As-4-320.jpg)
![Anomalous
[As] were
reported in
soil data
compiled
by HIDoH](https://image.slidesharecdn.com/6135159d-c5d2-48dd-b52e-d95bf74f3589-150418162249-conversion-gate02/85/Oahu-Soil-Sediment-As-7-320.jpg)
![Conclusions
As occurs in nearshore O併ahu sediments
NMDS indicates a loose association with
terrestrial elements (probably from runoff)
As occurs in some NAWQA stream
sediments associated with agriculture
PCA of NAWQA sediments indicate a loose
association with petrogenic elements but
not anthropogenic elements
HIDoH data show elevated [As] but the
distribution is spotty](https://image.slidesharecdn.com/6135159d-c5d2-48dd-b52e-d95bf74f3589-150418162249-conversion-gate02/85/Oahu-Soil-Sediment-As-16-320.jpg)
![Conclusions (continued)
Some As may be associated with past
sugarcane and/or pineapple agriculture
(arsenical pesticides ceased late 1940s,
super-phosphate fertilizers, etc.)
The highest [As] on O併ahu, however, are
found in mixed land use/forested areas
Arsenical pesticides & micronutrient
fertilizers (e.g., Ironite速) used in nurseries
may explain some As
And, finally](https://image.slidesharecdn.com/6135159d-c5d2-48dd-b52e-d95bf74f3589-150418162249-conversion-gate02/85/Oahu-Soil-Sediment-As-17-320.jpg)
Oahu Soil & Sediment As
- 1. Distribution & Abundance of Arsenic (As) in the Soils & Sediments of O併ahu, Hawai併i Michael S. Tomlinson, Eric H. De Carlo, Sara Thomas, & Laura E. deGelleke
- 2. O併ahu, Hawai併i O併ahu Hawai併i Maui Kaua併i Moloka併i Lna併i Kaho併olawe Ni併ihau Ordnance Reef Remedial Investigation Diamond Head HonoluluBarbers Point Ka併ena Point Kahuku Point Makapu併u Point Kailua Kne併ohe Mmala Bay Wai併anae
- 3. Ordnance Reef RI Where did the As come from? Nonmetric Multidimensional Scaling (NMDS)
- 4. Anomalous [As] were seen in bed sediments during USGS NAWQA Study A = Agriculture F = Forested U = Urban M = Mixed
- 5. Anthropogenic Trace Elements? ??? Arsenical Pesticides (e.g., NaAsO2), Super-phosphate Fertilizers?
- 7. Anomalous [As] were reported in soil data compiled by HIDoH
- 8. Arsenic Sources & Transfer
- 9. O併ahu Relief, Isohyets, & UHM Samples
- 10. As & Former Sugarcane Land
- 11. As & Former/Current Pineapple Land
- 13. As in Waiakeakua Stream
- 14. Why is arsenic in Waiakeakua Stream?
- 15. Where does the arsenic come from? Possibly iron & zinc micronutrient fertilizer from silver mine tailings used by nurseries to green-up plants (Human Health Risk Assessment for Long-term Residential Use of Ironite速 Lawn and Garden Nutrient Supplement - ADEQ, 1998)
- 16. Conclusions As occurs in nearshore O併ahu sediments NMDS indicates a loose association with terrestrial elements (probably from runoff) As occurs in some NAWQA stream sediments associated with agriculture PCA of NAWQA sediments indicate a loose association with petrogenic elements but not anthropogenic elements HIDoH data show elevated [As] but the distribution is spotty
- 17. Conclusions (continued) Some As may be associated with past sugarcane and/or pineapple agriculture (arsenical pesticides ceased late 1940s, super-phosphate fertilizers, etc.) The highest [As] on O併ahu, however, are found in mixed land use/forested areas Arsenical pesticides & micronutrient fertilizers (e.g., Ironite速) used in nurseries may explain some As And, finally
- 18. Yes, arsenic occurs naturally in Arizona, however, do not totally discount anthropogenic sources Photo taken in Flagstaff Sams Club
- 19. Mahalo nui loa! Questions? Mlama i ko mkou 併ina (Care for our land)