Keith A Loftin, Ph.D.

Water samples were collected from Maumee Bay State Park Lakeside Beach, Oregon, Ohio, during the 2012 recreational season and analyzed for selected cyanobacteria gene sequences by DNA-based quantitative polymerase chain reaction (qPCR) and RNA-based quantitative reverse-transcription polymerase chain reaction (qRT-PCR). Results from the four DNA assays (for quantifying total...

Cyanobacteria cause a multitude of water-quality concerns, including the potential to produce toxins and taste-and-odor compounds. Toxins and taste-and-odor compounds may cause substantial economic and public health concerns and are of particular interest in lakes, reservoirs, and rivers that are used for drinking-water supply, recreation, or aquaculture. The Kansas River is a primary...

Cyanotoxins are a group of organic compounds biosynthesized intracellularly by many species of cyanobacteria found in surface water. The United States Environmental Protection Agency has listed cyanotoxins on the Safe Drinking Water Act's Contaminant Candidate List 3 for consideration for future regulation to protect public health. Cyanotoxins also pose a risk to humans and other...

Rodeo Lagoon, a low-salinity coastal lagoon in the Golden Gate National Recreation Area, California, United States, has been identified as an important ecosystem due to the presence of the endangered goby (Eucyclogobius newberri). Despite low anthropogenic impacts, the lagoon exhibits eutrophic conditions and supports annual episodes of very high phytoplankton biomass. Weekly assessments...

Antibiotic transport downstream from a wastewater treatment plant effluent discharge was evaluated along stream reaches on Mud Creek, Spring Creek, and Decatur Branch in northwestern Arkansas, USA. Water and streambed samples were collected during August and September 2006 and analyzed for multiple antibiotics representing five classes (beta-lactams, macrolides, quinolones, sulfonamides...

Water shortages in the southeastern United States have led to a need for more intensive management and usage of stormwater for beneficial uses such as irrigation. Harvesting of infiltrated stormwater from horizontal wells in sandy aquifer sediments beneath stormwater ponds has emerged as an alternative in need of evaluation. Cyanobacteria may proliferate in stormwater ponds; cyanotoxins...

The mixtures of toxins and taste-and-odor compounds present during cyanobacterial blooms are not well characterized and of particular concern when evaluating potential human health risks. Cyanobacterial blooms were sampled in twenty-three Midwestern United States lakes and analyzed for community composition, thirteen cyanotoxins by liquid chromatography/mass spectrometry and immunoassay...

Although livestock operations are known to harbor elevated levels of antibiotic resistant bacteria, few studies have examined the potential of livestock waste lagoons to reduce antibiotic resistance genes (ARGs). The purpose of this study was to determine the prevalence and examine the behavior of tetracycline [tet(O) and tet(W)] and sulfonamide [sul(I) and su/(II)] ARGsin a broad cross...

Environmental releases of antibiotics from concentrated animal feeding operations (CAFOs) are of increasing regulatory concern. This study investigates the use and occurrence of antibiotics in dairy CAFOs and their potential transport into first-encountered groundwater. On two dairies we conducted four seasonal sampling campaigns, each across 13 animal production and waste management...

The U.S. Geological Survey method (0-2141-09) presented is approved for the determination of glyphosate, its degradation product aminomethylphosphonic acid (AMPA), and glufosinate in water. It was was validated to demonstrate the method detection levels (MDL), compare isotope dilution to standard addition, and evaluate method and compound stability. The original method USGS analytical...

Organic wastewater contaminants (OWCs) were measured in samples collected from monitoring wells located along a 4.5-km transect of a plume of groundwater contaminated by 60 years of continuous rapid infiltration disposal of wastewater treatment plant effluent. Fifteen percent of the 212 OWCs analyzed were detected, including the antibiotic sulfamethoxazole (SX), the nonionic surfactant...

A collaboration was developed between Abraxis, LLC, the State of Delaware Department of Natural Resources and Environmental Control Division of Water Resources Environmental Laboratory, the University of Delaware, and the United States Geological Survey to investigate the efficacy of the QuikLyse procedure developed by Abraxis, LLC as an alternative cell-lysis technique suitable for use...