|WASHINGTON, MAURICE - Iowa State University|
|SOUPIR, MICHELLE - Iowa State University|
|SHELLEY, MACK - Iowa State University|
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 3/31/2016
Publication Date: 9/18/2017
Citation: No Citation: abstracts are distributed on USB device to meeting participants.
Interpretive Summary: The production of swine often involves the use of antibiotics to control disease. Application of swine manure to farm lands may result in the movement of antibiotics into streams. We studied the occurrence of tylosin (TYL) and sulfamethazine (SMZ), antibiotics commonly used in swine production in the South Fork of the Iowa River from 2013–2015. Drainage water from fields and stream water were monitored for antibiotics and atrazine using specialized samplers placed in streams and drains. Both antibiotics were detected in 69–100% of the water samples from the watershed. Antibiotics were detected more often using POCIS when compared to samples analyzed by conventional methods. Seasonal increases in SMZ and ATZ concentrations were observed during the growing season and after harvest. SMZ and TYL concentrations were lower than the minimum inhibitory concentrations for E. coli, which suggests that antibiotics at these concentrations are not selecting for antibiotic resistance. Both antibiotics were detected in tile drainage water, confirming tile drainage as a pathway for antibiotic transport. The results inform scientists and the agricultural community about antibiotics in public waters and contribute to the discussion of risks associated with antibiotic use.
Technical Abstract: The seasonal occurrence, fate, and transport of agricultural emerging contaminants (AECs) was evaluated in the South Fork watershed of the Iowa River (SFIR) using Polar Organic Chemical Integrative Samplers (POCIS) over a three year period. The AECs of concern were tylosin (TYL) and sulfamethazine (SMZ), antibiotics commonly used in swine production. The SFIR is dominated by 96% agricultural land covers with 80% of the watershed under tile drainage. Approximately 169 animal feeding operations (AFOs) exist in the watershed with 153 of them being swine facilities. Tylosin and sulfamethazine were detected across the watershed, with detection frequencies of 81.8% and 58.8% respectively. The time weighted average (TWA) concentrations quantified from the POCIS were 0.78 ng L-1 (TYL) and 2.91 ng L-1 (SMZ) across the SFIR. This study demonstrated the ability of the POCIS to detect antibiotics at low concentrations and to monitor tile drain effluent in agricultural watersheds.