Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 3 of 3

Full-Text Articles in Other Pharmacology, Toxicology and Environmental Health

Herbicide Toxicity To Non-Target Aquatic Organisms Does Not Increase In Mixtures With Surfactants, Courtney L. Telfort May 2019

Herbicide Toxicity To Non-Target Aquatic Organisms Does Not Increase In Mixtures With Surfactants, Courtney L. Telfort

Honors College Theses

Agricultural herbicides enter aquatic environments after rain events where they affect microscopic aquatic plants (phytoplankton) and animals (zooplankton) that form the base of aquatic food webs. Atrazine, an herbicide with low solubility in water, is often mixed with surfactants such as alkyl polyglucoside (APG) to improve effectiveness. Although APG has low-toxicity, a potential drawback to increased atrazine solubility is greater adverse effects on aquatic organisms. I hypothesized that atrazine and APG decrease phytoplankton abundance more than atrazine alone. Specifically, I predicted phytoplankton abundance should 1) decrease with increasing concentrations of the mixture compared to the same atrazine concentrations individually, and …


Macrophytes And Atrazine In Ponds Of Southwest Missouri, Christine Michelle Cornish Aug 2018

Macrophytes And Atrazine In Ponds Of Southwest Missouri, Christine Michelle Cornish

Graduate Theses/Dissertations

Wetlands are often the ultimate destination of agrochemicals. The increased use of these pollutants has resulted in their increased transport, via runoff and spray drift, into wetlands. Atrazine, a commonly used herbicide, has been detected in surface water, groundwater, soil, and sediment, and has shown to have adverse impacts on aquatic biota, such as fish and amphibians. Few studies have reported on the relationships between atrazine and macrophytes. I measured atrazine concentrations in surface sediments in agricultural, conservation, and golf course ponds of southwest Missouri, and investigated how those concentrations might be related to macrophyte communities, and pond environmental characteristics. …


The Combined Effects Of Atrazine And Tetracycline On Primary Producers And Zooplankton In Freshwater Microcosms, Madison R. Kelly Apr 2018

The Combined Effects Of Atrazine And Tetracycline On Primary Producers And Zooplankton In Freshwater Microcosms, Madison R. Kelly

Honors College Theses

Widespread use of agrochemicals such as herbicides and antibiotics increases their likelihood of entering aquatic systems in mixture. Despite different modes of action, atrazine (herbicide) and tetracycline (antibiotic) adversely affect non-target photosynthetic organisms, such algae and macrophytes, with the potential to reduce food availability to higher trophic levels. However, the effects of simultaneous exposure to both contaminants have yet to be determined. I hypothesized that a mixture of atrazine and tetracycline affects freshwater communities differently than each compound alone. A microcosm experiment was conducted to test effects of environmentally relevant concentrations of atrazine (1 μg L-1) and tetracycline …