Back to Annual Meeting Page		American Public Health Association 133rd Annual Meeting & Exposition December 10-14, 2005 Philadelphia, PA

Abstract #117805

Hillary D. Strayer, Environmental and Occupational Health, University of South Florida College of Public Health, 13201 Bruce B. Downs Blvd., Tampa, FL 33612, (813) 974-5291, hstrayer@hsc.usf.edu

Deposition of nutrients to Tampa Bay estuary, largely from anthropogenic sources, has been shown to increase algal growth and decrease water quality in the estuary. The over–abundance of algae and subsequent eutrophication reduce water clarity and available dissolved oxygen. This can lead to fish kills, or a modified ecosystem causing migration out of the estuary, which diminishes local income from tourism and fishing.

This analysis determined the relative amounts of nitrogen wet deposition based on the origin of the air mass arriving at Tampa Bay. The purpose was to obtain estimates of local vs. transported nitrogen present in rainfall.

Air mass trajectories were obtained from 1996 to 2004, and classified as Tampa (local), Cape Canaveral, Bahamas, Cuba, Gulf, and Panhandle. The NADP AIRMON Gandy site provided precipitation physical and chemical measurements. Nitrogen wet deposition fluxes were calculated from ammonium and nitrate concentrations and depth of rainfall.

The Tampa trajectory had the highest per event nitrate flux (0.049 kg/ha), but had a lower ammonium flux (0.022 kg/ha) than all but one external trajectory (Gulf), confirming ammonium transport from distant sources. The total eight-year deposition to Tampa Bay from all trajectories was 17 kg/ha nitrate and 13 kg/ha ammonium.

Nitrogen fluxes calculated for six trajectory directions showed the lowest fluxes originated from the Gulf of Mexico, and the highest contribution came from east and south of the bay, a region of industry and agriculture. Remediation efforts in that area would have the most effect on reducing nutrient loading to the bay.

Learning Objectives: After viewing and discussing this poster, the participant will be able to

• Access on-line precipitation data generated for various sampling sites around the country
• Calculate nitrate and ammonium nitrogen flux for precipitation deposition 3)Ddetermine the relative contributiuons of the nitrogen flux from different regions of the airshed
• Be able to make suggestions about targets for control measures to reduce deposition from precipitation and improve the water quality in local bodies of water.

Keywords: Air Pollutants, Environment

Presenting author's disclosure statement:

I wish to disclose that I have NO financial interests or other relationship with the manufactures of commercial products, suppliers of commercial services or commercial supporters.