Abstract

The European Water Framework Directive requires surface water bodies to have a good chemical and ecological status. Although relatively few pesticides are included in the list of priority pollutants, they pose, due to their intrinsic biological activity, a significant risk for the integrity of aquatic ecosystems. In this context, the pesticide (up to 128 pesticides including some transformation products) exposure pattern in four agricultural streams and two rivers was determined from 2002 to 2011 under the umbrella of the Swedish national monitoring program employing time-proportional and grab sampling strategies, respectively. After transforming the measured pesticide concentrations into toxic units, the European Uniform Principles for algae (chronic), invertebrates and fish (both acute), which are partly employed as benchmark for pesticide regulation, were only occasionally (<2%) exceeded. Moreover, this evaluation showed no long-term trends over the years. However, recent publications suggested that those thresholds are not protective for ecosystem structure and function, indicating a risk of up to 20% and 35% of the samples from the agricultural streams and the rivers, respectively. Moreover, the monitoring data show a continuous but rather low toxic potential of pesticides for all three trophic levels throughout the year, which suggests pesticides as an evolutionary force in agriculturally impacted aquatic ecosystems. However, the flow-triggered sampling, which was implemented as an additional sampling strategy in one of the agricultural streams starting in 2006, displayed an up to 7-fold underestimation of the maximum concentration in terms of toxic units for daphnids and fish during run-off events. The present study thus underpins that the optimal sampling design for pesticide monitoring strongly depends on its overall purpose. If the long-term exposure pattern is of concern a time-proportional composite sampling strategy is recommended, while for an assessment of peak exposures a flow-event-triggered high-resolution sampling strategy is superior. (C) 2014 Elsevier B.V. All rights reserved.

Keywords

Plant protection product; Passive sampling; Chemical monitoring; Surface water; Acute toxicity; Standard test organisms

Published in

Science of the Total Environment
2014, Volume: 484, pages: 84-91
Publisher: ELSEVIER SCIENCE BV

SLU Authors

• Bundschuh, Mirco

  • Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences
    
  • University of Koblenz-Landau

• Goedkoop, Willem

  • Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences
    

• Kreuger, Jenny

  • Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences
    

Associated SLU-program

SLU Plant Protection Network


Sustainable Development Goals

SDG6 Ensure availability and sustainable management of water and sanitation for all
SDG15 Protect, restore and promote sustainable use of terrestrial ecosystems, sustainably manage forests, combat desertification, and halt and reverse land degradation and halt biodiversity loss


UKÄ Subject classification

Other Biological Topics


Publication identifier

DOI: https://doi.org/10.1016/j.scitotenv.2014.03.015

Permanent link to this page (URI)

https://res.slu.se/id/publ/63612