Exposure and potential effects of pesticides and pharmaceuticals in protected streams of the US National park Service southeast region

Authors

Paul M. Bradley, U.S. Geological Survey, South Atlantic Water Science CenterFollow
Kristin M. Romanok, U.S. Geological Survey, New Jersey Water Science Center
Jeffrey R. Duncan, National Park Service, Southeast Region, Chattanooga
William A. Battaglin, U.S. Geological Survey, Colorado Water Science Center
Jimmy M. Clark, U.S. Geological Survey, South Atlantic Water Science Center
Michelle L. Hladik, U.S. Geological Survey, California Water Science Center
Bradley J. Huffman, U.S. Geological Survey, South Atlantic Water Science Center
Luke R. Iwanowicz, U.S. Geological Survey, Leetown Science Center
Celeste A. Journey, U.S. Geological Survey, South Atlantic Water Science Center
Kelly L. Smalling, U.S. Geological Survey, New Jersey Water Science Center

Date of this Version

11-23-2019

Citation

https://doi.org/10.1016/j.scitotenv.2019.135431

0048-9697/Published by Elsevier B.V.

Comments

U.S. Government Works are not subject to copyright.

Abstract

Globally, protected areas offer refugia for a broad range of taxa including threatened and endangered species. In the United States (US), the National Park Service (NPS) manages public lands to preserve biodiversity, but increasing park visitation and development of surrounding landscapes increase exposure to and effects from bioactive contaminants. The risk (exposure and hazard) to NPS protected-stream ecosystems within the highly urbanized southeast region (SER) from bioactive contaminants was assessed in five systems based on 334 pesticide and pharmaceutical analytes in water and 119 pesticides in sediment. Contaminant mixtures were common across all sampled systems, with approximately 24% of the unique analytes (80/334) detected at least once and 15% (49/334) detected in half of the surface-water samples. Pharmaceuticals were observed more frequently than pesticides, consistent with riparian buffers and concomitant spatial separation from non-point pesticide sources in four of the systems. To extrapolate exposure data to biological effects space, site-specific cumulative exposure-activity ratios (REAR) were calculated for detected surface-water contaminants with available ToxCast data; common exceedances of a 0.001 REAR effects-screening threshold raise concerns for molecular toxicity and possible, sub-lethal effects to non-target, aquatic vertebrates. The results illustrate the need for continued management of protected resources to reduce contaminant exposure and preserve habitat quality, including prioritization of conservation practices (riparian buffers) near stream corridors and increased engagement with upstream/up-gradient property owners and municipal wastewater facilities.