Gary R.W. Denton
Professor of Environmental Toxicology
Water & Environmental Research Institute of the Western Pacific
University of Guam
Mangilao, GU 96923
Phone: 671-735-2690 (fax 734-8890) (GMT+10 hrs)
[email protected]
Ph.D. Marine Zoology, Westfield College, University of London B.Sc. Biological Sciences, Westfield College, University of London
| RESEARCH | Research Interests | Projects | |
| COURSES: | Environmental Contamination and Toxicology I & II | Instrumental Analysis | |
| PUBLICATIONS: |
RESEARCH INTERESTS
Dr. Denton’s primary research interests center on water quality with emphasis on contaminant transport, fate and toxicity, bioindicators and the development of novel pollution monitoring strategies. He leads the Pollution Monitoring and Assessment Program at WERI and is currently evaluating the ecological impact of landfill leachate, urban runoff, wastewaters and industrial discharges on aquatic systems in Guam and the CNMI. Some of his recently completed works deal with the aqueous chemistry of local wetlands; toxic contaminants in harbor sediments and biota; pesticide persistence and mobility in local soils; the biological impact of urban runoff on coastal communities, and sources and effects of nutrient enrichment in nearshore waters.
This project was initiated in response to relatively high levels of mercury being detected in fish from the Micro Beach area in the northern section of Garapan Lagoon, Saipan. Soil from drainage basins within the Garapan area and sediments from the coastal belt are currently being analyzed in an attempt to locate possible terrestrial source of contamination and identify drainage pathways into the lagoon. Biotic representatives from this popular fishing spot are also being considered. Potential sources of mercury contamination so far identified include the local hospital and a newspaper printing press. Soil from a drainage ditch in the grounds of the former site contained in excess of 1200 ng Hg/g dry weight of soil -- approximately 40 times higher than normal background levels. Expected completion date: Summer 2008. (Funding source: US Geological Survey).
PCB, mercury and arsenic are being screened in popular table fish from Tanapag Lagoon, Saipan, as part of an ongoing pollution contamination and assessment program for this area. Specimens are being analyzed from nearshore and offshore locations within the lagoon in order to identify and delineate terrestrial source of contamination. Species selected for study include those with restricted foraging ranges as well as those that are more roving in their feeding habits. To date, some 360 fish representing 65 different species from various trophic levels have been analyzed for mercury and arsenic. PCB analysis is currently underway. Mercury and arsenic levels detected in the axial muscle of samples analyzed range from 0.006-0.616 µg/g wet weight and 0.027-36.13 µg/g wet weight respectively. Total PCB concentrations (sum of 20 congeners) encountered in axial muscle of fish so far examined range from 0.47-46.4 ng/g wet weight. Data evaluations of all three contaminants will include a human health risk assessment. Expected completion date: Summer 2008. (Funding source: US Geological Survey)
The study is focusing on dominant ecological representatives that inhabit the shallow nearshore waters of Tanapag Lagoon, Saipan, with emphasis on groups with high bioindicator potential that are either sessile or are restricted in their movement e.g., algae, seagrass, seacucumbers, bivalves and juvenile fish. Representatives of each are currently being collected from intertidal sites along the entire length of the lagoon. Most of these sites were impacted by land-based sources of contamination of one sort or another. Metals of interest include arsenic, cadmium, chromium, copper, lead, mercury, nickel, silver and zinc. The data are being evaluated with reference to similar and related species collected from tropical environments elsewhere in the world. Expected completion date: Summer 2008. (Funding source: US Geological Survey)
Recently Completed Projects:
Completed in 2001, this project mapped heavy metal, PCB and PAH profiles in surface sediments from Tanapag Lagoon on the western shore of central Saipan (see WERI Technical Report No. 93). This large lagoon is heavily impacted by the activities of man including a major seaport and bulk fuel facility, a power station, two small boat marinas, sewer outfall, and a municipal dump. The area is also heavily inundated by stormwater runoff during prolonged periods of wet weather. Areas of contaminant enrichment were identified around the port, marinas and dump. (Funding source: US Geological Survey)
Completed in 2001, this project examined dissolved inorganic nitrogen (DIN) and reactive phosphorus (RP) levels in groundwater seeps and springs entering Tumon Bay, Guam’s premier tourist location (see WERI Technical Report No. 110). The primary objective of this research was to identify the potential role hotel landscaping activities played in promoting the extensive blooms of Enteromorpha clathrata found along the beach. Overall, RP levels in seeps and springs within the bay were found to be marginally higher than aquifer samples taken further inland. Threshold levels of DIN required to promote algal blooms immediately offshore were generally present in oversupply while RP levels were frequently limiting. The research highlighted the dramatic effect relatively small anthropogenic inputs of RP could have on the distribution and abundance of E. clathrata within the bay. (Funding source: US Geological Survey)
Completed in 2003, this project determined the chemical and biological characteristics of leachate emanating from Ordot Landfill in central Guam and their potential impact on water surface water resources in the area. This landfill has been in continuous use for over 50 years and has no leachate retention system in place. It was slated for closure almost 30 years ago and has been operating at over capacity for at least ten. Identified contaminants of concern in leachate sample collected from around the periphery of the landfill included fecal indicator bacteria, nitrogen, phosphorus and several heavy metals (see WERI Technical Report No. 108). Surface and subsurface waters down gradient of the landfill were monitored periodically for these contaminants over one year. (Funding source: US Geological Survey)
Completed in 2006, this project examined the heavy metal status of sediments and bioindicator organisms (algae, seagrass, seacucumbers and bivalve mollusks) from Pago Bay previously considered the final resting place of aqueous contaminants flushed out of the Ordot Landfill into the Lonfit-Pago River system. The results of this investigation clearly showed otherwise (see WERI Technical Report No. 113). (Funding source: US Geological Survey)
PUBLICATIONS
Journal Articles
Denton, G.R.W., Olsen, M.C. and Wen, Y. The Impact of Metal Enriched from a Landfill in Central Guam on the Heavy Metal Status of Sediments and Aquatic Organisms within the Watershed. Micronesica, (in review)
Denton, G.R.W., Golabi, M.H.,Wood, H.R., Iyekar, C., Concepcion, L.P. and Wen, Y. Impact of Ordot Dump on Water Quality of the Lonfit River Basin in Central Guam. 2. Aqueous Chemical and Biological Contaminants. Micronesica, (in press).
Golabi, M.H., Denton, G.R.W., Wood, H.R., Wen, Y. and Iyekar, C. (2007). Impact of Ordot Dump on Water Quality of the Lonfit River Basin in Central Guam. 1. Soil Characterization and Nutrient Retention. Micronesica, 39 (1): 41-54.
Denton, G.R.W. and Sian-Denton, C.M. (2007). Unsightly Algal Blooms in Tumon Bay, Guam’s Premier Tourist Location: Possible Connection to Hotel Landscaping Activities. Journal Interdisciplinary Environmental Review, IX (1): 94-106.
Vuki, M., Limtiaco, J., Aube, T., Emmanuel, J., Denton, G.R.W., and Wood, H.R. (2007). Arsenic Speciation Study in Some Spring Waters of Guam, Western Pacific Ocean, Science of the Total Environment, 379: 176-179.
Denton, G.R.W., Concepcion, L.P., Wood, H.R. and Morrison R.J. (2006). Trace Metals in Marine Organisms from Four Harbours in Guam. Marine Pollution Bulletin, 52: 1784-1804
Denton, G.R.W., Concepcion, L.P., Wood, H.R. and Morrison R.J. (2006) Polycyclic Aromatic Hydrocarbons (PAHs) in SmallIsland Coastal Environments: A Case Study from Harbours in Guam, Micronesia. Marine Pollution Bulletin, 52:1090-1098.
Denton, G.R.W., Concepcion, L.P., Wood, H.R. and Morrison R.J. (2006). Polychlorinated Biphenyls (PCBs) in Sediments from Four Harbours in Guam. Marine Pollution Bulletin, 52: 711-718.
Denton, G.R.W., Bearden, B. Concepcion, L.P., Wood, H.R. and Morrison R.J. (2006). Contaminant Assessment of Surface Sediments from Tanapag Lagoon, Saipan, Marine Pollution Bulletin, 52: 703-710.
Denton, G.R.W., Concepcion, L.P., Wood, H.R. and Morrison R.J. (2006). Polychlorinated Biphenyls (PCBs) in Marine Organisms from Four Harbours in Guam. Marine Pollution Bulletin 52: 214-238
Denton, G.R.W., Concepcion, L.P., Wood, H.R. and Morrison R.J. (2005). Trace Metals in Sediments of Four Harbours in Guam. Marine Pollution Bulletin, 50: 1133-1141.
Muniappan, R., Denton G.R.W., Brown, J.W., Lali, T.S., Prasad, U. and Singh, P. (1996). Effectiveness of the Natural Enemies of Lantana camara on Guam: A Site and Seasonal Evaluation. Entomophaga, 41: 167-182.
Denton, G.R.W. and Heitz, L.F. (1993). Heavy Metal Uptake and Loss in the Burrowing Clam, Tridacna crocea: Implications from a Public Health and Mariculture Viewpoint. In: Biology and Mariculture of Giant Clams. W.K. Fitt (ed.) ACIAR Monograph Series No. 47. Pirie Printers, Canberra, Australia. 154 p.
Muniappan, R., Denton, G.R.W., Marutani, M., Lali, T.S. and Kimmons, C.A. (1993). Fruit Piercing Moths in Micronesia and their Natural Enemies. Micronesica, Suppl., 4: 33-39.
Marutani, M., Muniappan, R. and Denton, G.R.W. (1992). Biological Control of Red Coconut Scale in Guam. Journal of Plant Protection in the Tropics, 9: 63-67.
Denton, G.R.W. and Heitz, L.F. (1991). Tridacna: Sentinels of Heavy Metal Pollution in Torres Strait Waters - a Critical Evaluation. In: Sustainable Development for Traditional Inhabitants of the Torres Strait Region. D. Lawrence and T. Cansfield-Smith (eds.) Great Barrier Reef Marine Park Authority Workshop Series No. 47. Australian Government Publishing Service, Canberra, Australia. 535 p.
Denton, G.R.W., Muniappan, R., and Marutani, M. (1991). Status and Natural Enemies of the Weed, Lantana camara, in Micronesia, Journal of Tropical Pest Management, 37(4): 334-337.
Denton, G.R.W., Muniappan, R., and Marutani, M. (1991). The Distribution and Biological Control of Lantana camara in Micronesia, Micronesica Suppl., 3: 71-81.
Darmono, D., Denton, G.R.W., and Campbell, R.S.F. (1990). The Pathology of Cadmium and Nickel Toxicity in the Banana Shrimp (Penaeus merguiensis de Man), Asian Fisheries Science, 3: 287-297.
Muniappan, R., Marutani, M. and Denton, G.R.W. (1988). Biological Control of Chromolaena odorata in the Western Caroline Islands. Journal of Biological Control, 2: 141-142.
Shelley, C., Glazebrook, J.S., Turak, E., Winsor, L. and Denton, G.R.W. (1988). Trematode (Digeanea: Bucephalidae) Infection in the Burrowing Clam Tridacna crocea from the Great Barrier Reef. Diseases of Aquatic Organisms, 4: 143-147.
Denton, G.R.W. and Winsor, L. (1986). Giant Clams as Indicators of Pollution. Oceanus 29(2): 63.
Bunt, J.S., Denton, G.R.W. et al. (1986). The Torres Strait. Habitat 13(6): 12-18.
Denton, G.R.W. and Burdon-Jones, C. (1986). Trace Metals in Surface Waters of the Great Barrier Reef. Marine Pollution Bulletin, 17: 96-98.
Denton, G.R.W. and Burdon-Jones, C. (1986). Trace Metals in Algae from the Great Barrier Reef. Marine Pollution Bulletin, 17: 98-107.
Denton, G.R.W. and Burdon-Jones, C. (1986). Trace Metals in Fish from the Great Barrier Reef. Marine Pollution Bulletin, 17: 201-209.
Denton, G.R.W. and Burdon-Jones, C. 1986. Trace Metals in Corals from the Great Barrier Reef. Marine Pollution Bulletin, 17: 209-213.
Denton, G.R.W. and Burdon-Jones, C. (1986). Environmental Effects on Toxicity of Heavy Metals to Two Species of Tropical Marine Fish from Northern Australia. Chemistry in Ecology, 2: 233-249.
Burdon-Jones, C., Denton, G.R.W., Jones, G.B. and McPhie, K.A. 1982. Regional and Seasonal Variations of Trace Metals in Tropical Phaeophyceae from North Queensland. Marine Environmental Research, 3: 361-369.
Denton, G.R.W., Marsh, H. Heinsohn, G.E. and Burdon-Jones, C. 1980. The Unusual Metal Status of the Dugong Dugong dugon. Marine Biology, 52: 201-219.
Denton, G.R.W. (1979). The Identification of By-products Obtained During Synthesis of Polychlorobiphenyls by the Van Roosmalen Procedure. Chemosphere, 8(2): 41-43.
Courtney, W.A.M. and Denton, G.R.W. (1976). Persistence of Polychlorinated Biphenyls in the Hard-shell Clam (Mercenaria mercenaria) and the Effects Upon the Distribution of these Pollutants in the Estuarine Environment. Environmental Research, 10: 56-64.
Ayres, D. C. and Denton, G.R.W. (1975). On the Diversity of Products Obtained During the Synthesis of Polychlorobiphenyls by the Van Roosmalen Procedure. Bulletin of Environmental Contamination and Toxicology, 14(3): 361-169.
Ayres, D. C. and Denton, G.R.W. 1972. Critical By-products in the Synthesis of Polychlorinated Biphenyls. Nature, 240 (5377): 161-162.
Technical Reports
Hoffman, S.M., Jenson, J.W., Moran, D., Denton, G.R.W., Wood, H.R. and Vacher, H.L. (2007). Background Fluorescence in Guam's coastal waters. Technical Report No. 121, Water and Environmental Research Institute (WERI) of the Western Pacific, University of Guam, Mangilao, Guam 96923. 48 pp.
Denton, G.R.W., Kelly, W.C., Wood, H.R. and Wen Y. (2006). Impact of metal enriched leachate from Ordot Dump on the Metal Status of Biotic and Abiotic Components in Pago Bay. Technical Report No. 113, Water and Environmental Research Institute (WERI) of the Western Pacific, University of Guam, Mangilao, Guam 96923. 63 pp.
Denton, G.R.W., Sian-Denton, C.M., Concepcion, L.P., and Wood, H.R. (2005). Nutrient Status of Tumon Bay in Relation to Intertidal Blooms of the Filamentous Green Alga, Enteromorpha clathrata. Technical Report No. 110, Water and Environmental Research Institute (WERI) of the Western Pacific, University of Guam, Mangilao, Guam 96923. 53 pp.
Denton, G.R.W., Golabi, M., Iyekar, C., Wood, H.R. and Wen Y. (2005). Mobilization of Aqueous Contaminants Leached from Ordot Landfill in Surface and Subsurface Flows. Technical Report No. 108, Water and Environmental Research Institute (WERI) of the Western Pacific, University of Guam, Mangilao, Guam 96923. 83 pp.
Denton, G.R.W., Bearden, B., Concepcion, L.P., Siegrist, H.G., Vann, D.T. and Wood, H.R. (2001). Contaminant Assessment of Surface Sediment from Tanapag Lagoon, Saipan. Technical Report No. 93, Water and Environmental Research Institute (WERI) of the Western Pacific, University of Guam, Mangilao, Guam 96923. 110 pp.
Denton, G.R.W., Concepcion, L.P., Wood, H.R., Eflin V.S., and Pangelinan G.T. (1999). Heavy Metals, PCBs and PAHs in Marine Organisms from Four Harbor Locations on Guam. A Pilot Study. Technical Report No. 87, Water and Environmental Research Institute (WERI) of the Western Pacific, University of Guam, Mangilao, Guam 96923. 154 pp.
Denton, G.R.W., Muniappan, R., Austin, L. and Diambra, O.H. (1999). Fruit-Piercing Moths of Micronesia. Technical Report No. 217, Agriculture Experiment Station, College of Agriculture and Life Sciences, University of Guam, Mangilao, Guam 96923. 26 pp.
Denton, G.R.W., Heitz, L.F., Wood, H.R., Siegrist, H. G., Concepcion, L.P. and Lennox, R. (1998). Urban Runoff in Guam: Major Retention Sites, Elemental Composition and Environmental Significance. Technical Report No. 84, Water and Environmental Research Institute (WERI) of the Western Pacific, University of Guam, Mangilao, Guam 96923. 212 pp.
Denton, G.R.W., Wood, H.R. and McConnell, J. (1998). Mobility and Persistence of Modern Day Pesticides in Soil Used to Construct the Fairways of the Guam International Country Club Golf Course.Technical Report No. 82, Water and Environmental Research Institute (WERI) of the Western Pacific, University of Guam, Mangilao, Guam 96923. 42 pp.
Denton, G.R.W., Wood, H.R., Concepcion, L.P., Siegrist, H.G., Eflin, V.S., Narcis, D.K. and Pangelinan, G.T. (1997). Analysis of In-Place Contaminants in Marine Sediments from Four Harbor Locations on Guam. A Pilot Study. Technical Report No. 81, Water and Environmental Research Institute (WERI) of the Western Pacific, University of Guam, Mangilao, Guam 96923. 120pp.
Siegrist, J., Denton G.R.W., Wood, H.R., Concepcion, L. P. and Lewis, R.R. (1997). Aqueous Chemistry of a Perennial Wetland in Southern Guam. Technical Report No. 79, Water and Environmental Research Institute (WERI) of the Western Pacific, University of Guam, Mangilao, Guam 96923. 58pp.
Siegrist, J., Denton G.R.W., Heitz, L.F., Matson, E.A., Rinehart, A.F. and Smith B.D. (1996). Wetlands Resources in the Ugum Watershed, Guam. A General Description and Preliminary Functional Assessment of a Palustrine-Riverine Wetland System. Technical Report No. 76, Water and Environmental Research Institute (WERI) of the Western Pacific, University of Guam, Mangilao, Guam 96923. 50pp.
Conference Proceedings
Denton, G.R.W., Olsen, M.C. and Wen, Y. (2007). Solid Waste Disposal in Guam: The Impact of an Unsanitary Landfill on the Metal Status of Adjacent Aquatic Community Representatives. In: Progress in Environmental Science and Technology (Vol I), (Eds. Wang, Y., Li, S., Huang, P., Yang, Y., An, Y. and Sun, X.) Proceedings of the 2007 International Symposium on Environment Science and Technology, Beijing, China, November 13-16, 2007. p. 1169-1176.
Denton, G.R.W., Wood, H.R. and McConnell, J. (1995). Mobility and Persistence of Chlorpyrifos in a Tropical Soil under Simulated Field Conditions Adopting a High Watering Regime. In: Proceedings of the American Water Resources Association Summer Symposium, Water Resources and Environmental Hazards: Emphasis on Hydrological and Cultural Insight in the Pacific Rim. R. Herrmann, W. Back, R.C. Sidle and A. I. Johnson (eds.), Honolulu, Oahu, Hawaii, June 25-28, 1995. p. 404-413.
Muniappan, R., Denton, G.R.W., Marutani, M., Lali, T.S. and Kimmons, C.A. (1992). Biological Control of Fruit Piercing Moths in Micronesia. In: Proceedings of the XIX International Congress of Entomology, Beijing, Peoples Republic of China, June 28- July 4, 1992. Micronesica, Suppl., 4: 33-39.
Denton, G.R.W., Muniappan, R., and Marutani, M. (1991). The Distribution and Biological Control of Lantana camara in Micronesia. In: Proceedings of the Pacific Science Association Scientific Committee for Entomology. Workshop on Exotic Pests in the Pacific - Problems and Solutions. R. Muniappan, M. Marutani and G.R.W. Denton (eds.). Micronesica Suppl., 3: 71-81.
Denton, G.R.W., Muniappan, R., Marutani, M., McConnell, J., Lali, T.S., Cruz, L., Afaisen, D., Meyer, S., Chiu, C.-H. and Esquerra, N. (1990). The Distribution and Biological Control of the Fruit Piercing Moth, Othreis fullonia (Lepidoptera : Noctuidae) in Micronesia. In: Proceedings Second ADAP Crop Protection Conference. I. Schreiner and D. Nafus (eds.), University of Guam, CALS Media Publication 11/92. p. 22-33.
Denton, G.R.W., Muniappan, R., Marutani, M., McConnell J. and Lali, T.S. (1989). Biology and Natural Enemies of the Fruit Piercing Moth, Othreis fullonia (Clerck) (Lepidoptera : Noctuiidae). In: Proceedings of ADAP Crop Protection Conference. M.W. Johnson, D.E. Ullman & A. Vargo (eds.). Hawaii Agriculture Experiment Station. HITAHR Research Extension Series 134, 1991. p.150-154.
Denton, G.R.W. (1986). Guidelines for Trace Metal Surveillance Studies in the Torres Strait and Adjacent Waters. In: Proceedings of Torres Strait Fisheries Conference, Port Moresby, February 1985. Australian Government Publishing Service, Canberra. p.251-265.
Presentations and Abstracts
Denton, G.R.W., Olsen, M.C. and Wen, Y. Solid Waste Disposal in Guam: The Impact of an Unsanitary Landfill on the Metal Status of Adjacent Aquatic Community Representatives. 13th International Interdisciplinary Conference on the Environment, June 30-July 3, 2007, Portland, Maine.
Sian-Denton and Denton, G.R.W. Microbiological Contaminants in Guam’s Groundwater Past and Present: Benefits of Sound Management Practices. 13th International Interdisciplinary Conference on the Environment, June 30-July 3, 2007, Portland, Maine.
Denton, G.R.W. and Sian-Denton, C.M. (2006). Unsightly Algal Blooms in Tumon Bay, Guam’s Premier Tourist Location: Possible Connection to Hotel Landscaping Activities. 12th International Interdisciplinary Conference on the Environment. Kona, Hawaii, June 22-24, 2006.
Sian Denton, C.M. and Denton G.R.W. (2006). Impact of Economic Growth and Urban Development on the Chemical Integrity of Guam’s Groundwater Resources. 12th International Interdisciplinary Conference on the Environment. Kona, Hawaii, June 22-24, 2006
Iyekar, C., Golabi, M., Denton, G.R.W. and Wood, H.R. (2003). Impact of Ordot Dump on Water Quality of Lonfit River Basin in Central Guam. 20th Pacific Science Congress, Bangkok, Thailand, March 17-21, 2003.
Denton, G.RW. (2001). Nutrient Sources and Pathways into Tumon Bay. In: Whose Business is the Environment?. Proceedings and Resource Guide of the 20th AnnualPacificIslands EPA Conference, Hyatt Hotel, Guam. June 11-15, 2001.
Denton, G.R.W. and Heitz L. F. (2001). Potential Impact of Landscaping Activities on the Nutrient Status of Tumon Bay, Guam. 10th Pacific Science Inter-Congress, Guam, June 1-6, 2001
Denton, G.R.W. and Siegrist H.G. (2001). Metal Deficiencies and Imbalances in Wetland Plants from Guam. 10th Pacific Science Inter-Congress, Guam, June 1-6, 2001
Concepcion, L and Denton G.R.W. (2001). PCBs in Agana Swamp, Guam: Historic Overview and Current Research. 10th Pacific Science Inter-Congress, Guam, June 1-6, 2001
Nadeau, T. and Denton G.R.W. (2001). Nutrient Studies in the Togcha River, Guam: Phosphorus and Total Organic Carbon. 10th Pacific Science Inter-Congress, Guam, June 1-6, 2001
Heitz, L.F. and Denton G.R.W. (2001). A Fully Automated Sequential Sampling Device for Monitoring Contaminants in Urban Runoff. 10th Pacific Science Inter-Congress, Guam, June 1-6, 2001
Okura, S., Denton, G.R.W., and Smith B. (2001). Imposex in Gastropod Molluscs from Apra Harbor, Guam. 10th Pacific Science Inter-Congress, Guam, June 1-6, 2001
Soto, A.D., Denton, G.R.W. and Wood H.R. (2001). Mobility and Persistence of Carbaryl in a Guam Soil. 10th Pacific Science Inter-Congress, Guam, June 1-6, 2001
Denton, G.RW. and Heitz L.F. (1999). Automated Sampling Systems for Pollution Detection and Unsightly Algal Blooms in Tumon Bay: The Hotel Connection. 18th Annual Pacific Islands EPA Conference, Saipan Diamond Hotel, Commonwealth of the Northern Mariana Islands, June 21-25, 1999.
Denton, G.R.W., Wood, H.R. and McConnell, J. (1996). Behavior of Chlorpyrifos in Soil Used for Fairway Construction at a Golf Course in Northern Guam: Preliminary Data on Adsorption/Desorption Characteristics and Degradation Rates. 4th WRRC Conference, Special Report SR-97-01 Water Resources Research Center, University of Hawaii, Honolulu, Hawaii, June 12-14, 1996
Denton, G.R.W. and Wood H.R. (1996). The Behavior of Chlorpyrifos in a Local Soil under Simulated Conditions of High Rainfall. Water Resources Management in the Pacific Rim Pacific Northwest/Oceania Conference, Guam, March 25-27, 1996.
Siegrist, H.G., Jr. and Denton G.R.W. (1993). Geomorphic Controls on Manganese Concentrations in Non-Tidal Wetlands on Guam. Prog. Geol. Soc. Amer. Natl. Mtg. Cincinnati
Denton, G.R.W. and Heitz, L.F. (1992). Trace Metal Kinetics in Giant Clams: Implications from a Mariculture Viewpoint. 7thInternational Coral Reef Symposium, Guam, 22-26 June 1992
Denton, G.R.W. (1990). Giant Clams: Bioindicators of Heavy Metal Pollution in Tropical Reef Waters. 11th Annual Meeting, Society of Environmental Toxicology and Chemistry, Arlington, Virginia, Nov. 11-15, 1990.
COURSES TAUGHT
This graduate course covers the fundamental principles and mechanisms governing the interaction of pollutants with natural systems. The basic concepts of classical and environmental toxicology are also addressed with emphasis on contaminant absorption, distribution, metabolism, systemic toxicology, carcinogenesis, toxicity testing, and risk assessment. The course concludes with a general introduction to air, land and water pollution.
This graduate course focuses on classic and contemporary groups of environmental contaminants and their impact on organisms, ecosystems and man. Physical and chemical properties of each contaminant group are discussed in relation to their environmental distribution, fate and toxicity. Occupational health related pollution problems and pollution monitoring strategies are also discussed.
This graduate course is designed to familiarize students with the fundamental principles of environmental sampling and analysis. It focuses on the methodologies and instrumentation currently used to determine a number of important chemical contaminants in the environment today. The course carries a strong practical component that exposes students to a range of state-of-the-art analytical technologies, including AAS, GLC, ASV, HPLC, IR, NMR and Mass Spec. Emphasis is placed on the importance of quality control and quality assurance protocols in the production of reliable and defensible data.