Measuring Antidepressants, Fungicides, and Insecticides in the Environment Completed

Sources/Usage: Public Domain.

Antidepressant Pharmaceuticals

USGS scientists have developed a laboratory analytical method to measure the concentrations of eight currently used antidepressants and two of their pharmaceutically active degradation byproducts (or metabolites) in environmental waters. Many of these antidepressants are from the class of antidepressant pharmaceuticals called Selective Serotonin Reuptake Inhibitors (SSRIs). This widely prescribed class of antidepressants, which includes citalopram (Celexa), escitalopram (Lexapro), fluoxetine (Prozac and Sarafem), fluvoxamine (Dumyrox, Luvox, …), paroxetine (Paxil and Pexeva), sertraline (Zoloft), and others, has been prescribed to millions of people worldwide. Recent studies by the USGS and others have detected other widely prescribed pharmaceuticals in wastewater and in streams downstream of the discharge from wastewater treatment plants (WWTPs). An initial application of the method to a stream in Texas receiving wastewater detected several antidepressant pharmaceuticals, such as bupropion (Wellbutrin and Zyban), citalopram, duloxetine (Cymbalta), fluoxetine, fluvoxamine, norfluoxetine (a metabolite of fluoxetine), norsertraline (a metabolite of sertraline), paroxetine, sertraline, and venlafaxine (Effexor). Concentrations ranged from less than one nanogram per liter (ng/L) to over 1,000 ng/L. The scientists conducting the study were the first to report detection of bupropion, duloxetine, and venlafaxine in natural aquatic environments.

Sources/Usage: Public Domain.

Agricultural Fungicide - Chlorothalonil

USGS scientists have developed analytical methods to measure the fungicide chlorothalonil and its environmental degradation byproducts in water, sediment, and soil. Chlorothalonil is used to control fungal diseases in peanuts, potatoes, fruit, and vegetable crops. The analytical method for water samples has been applied to study streams in areas of Alabama, Florida, Georgia, Oklahoma, and Texas where peanuts are grown. The method for sediment and soil has been applied to study sediments in Alabama, Florida, and Georgia streams draining areas where peanuts are grown. Chlorothalonil and its degradation byproducts were detected infrequently, and when detected, were found at relatively low concentrations (less than one microgram per liter).

Pyrethroid Insecticides

USGS scientists and their partners have developed a sensitive analytical method to measure several pyrethroid insecticides in sediments from streams--sediments suspended in water as well as on the bottom of streams. Pyrethroids are a class of insecticides that are widely used, including for agricultural purposes, home and garden use, and mosquito control. USGS scientists applied the new method to study pyrethroids in stream sediments in three California watersheds where the chemicals are widely used. The scientists detected pyrethroids in sediments in streams downstream of application areas in all of the watersheds. Concentrations of individual pyrethroids (such as bifenthrin and permethrin) in sediment ranged as high as tens of nanograms per gram dry weight. This study was one part of a multi-agency effort where the USGS has partnered with the California Departments of Pesticide Regulation and Fish and Game, with funding from the CALFED Bay-Delta Program, to develop analytical methods to detect pyrethroids in water, sediments, and biological organisms.

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