Spatial and Temporal Patterns of Endocrine Active Chemicals in Small Streams Indicate Differential Exposure to Aquatic Organisms

Abstract

Alkylphenolic chemicals (APCs) and hormones were measured six times from February through October 2007 in three Minnesota streams receiving wastewater to identify spatial and temporal patterns in concentrations and in estrogen equivalency. Fish were collected once during the study to evaluate endpoints indicative of endocrine disruption. The most commonly detected APCs were 4‐tert‐octylphenol and 4‐nonylphenol and the most commonly detected hormones were estrone and androstenedione. Chemical concentrations were greatest for nonylphenol ethoxycarboxylates (NPECs) (5,000‐140,000 ng/l), followed by 4‐nonlylphenol and 4‐nonylphenolethoxylates (50‐880 ng/l), 4‐tert‐octylphenol and 4‐tert‐octylphenolethoxylates with concentrations as great as 130 ng/l, and hormones (0.1‐54 ng/l). Patterns in chemicals and estrogen equivalency indicated that wastewater effluent is a pathway of APCs and hormones to downstream locations in this study. However, upstream contributions can be equally or more important indicating alternative sources. This study indicates that aquatic organisms experience both spatially and temporally variable exposures in the number of compounds, total concentrations, and estrogenicity. This variability was evident in fish collected from the three rivers as no clear upstream to downstream pattern of endocrine disruption endpoints emerged.

On‐site, serial exposure of female fathead minnows to the Elkhorn River, Nebraska, USA, spring agrichemical pulse

“…This is different from feminization of male fish, in which the activation of estrogen-responsive traits is unlikely to be induced by environmental factors. Although a number of studies have characterized seasonal effects in the feminization of male fish after environmental estrogens downstream of wastewater treatment plants [2,[26][27][28][29] considerably fewer studies have investigated in situ anti-estrogenic exposures [9,10,17].…”

Featured Collection Introduction: Contaminants of Emerging Concern II

“…In the 12th article, Lee et al . () identify spatial and temporal patterns in concentrations of alkylphenolic compounds, along with their estrogen equivalency in three Minnesota streams. A one‐time collection of fish was also conducted during the study to evaluate endpoints indicative of endocrine disruption.…”