How a complete pesticide screening changes the assessment of surface water quality.

A comprehensive assessment of pesticides in surface waters is challenging due to the large number of potential contaminants. Most scientific studies and routine monitoring programs include only 15-40 pesticides, which leads to error-prone interpretations. In the present study, an extensive analytical screening was carried out using liquid chromatography-high-resolution mass spectrometry, covering 86% of all polar organic pesticides sold in Switzerland and applied to agricultural or urban land (in total 249 compounds), plus 134 transformation products; each of which could be quantified in the low ng/L range.

Estimating catchment vulnerability to diffuse herbicide losses from hydrograph statistics.

The prediction of diffuse herbicide losses to surface waters using process-based models is data and time demanding. There is a need for simpler and more efficient catchment screening tools. We developed and tested a new proxy for screening catchments for their vulnerability to diffuse herbicide losses relying on widely available river flow data only.

Comparison of atrazine losses in three small headwater catchments.

Understanding the processes causing herbicide transport to surface waters is crucial to determine mitigation options to reduce these losses. To this end, we investigated the atrazine (2-chloro-4-ethylamino-6-isopropylamino-1,3,5-triazine) transport in three agricultural catchments (1.1-2.

Competitive sorption of protons and metal cations onto kaolinite: experiments and modeling.

Competitive sorption of protons, Cu, and Pb onto kaolinite (KGa-2) was investigated over wide concentration ranges and quantitatively described using three different models based on surface complexation and cation exchange reactions. In all models, two types of binding sites were assumed for kaolinite: edge sites (SOH0.5-) with pH-dependent charge and face sites (X-) with permanent negative charge.

Variability of herbicide losses from 13 fields to surface water within a small catchment after a controlled herbicide application.

Diffuse losses from agricultural fields are a major input source for herbicides in surface waters. In this and in a companion paper, we present the results of a comprehensive field study aimed at assessing the overall loss dynamics of three model herbicides (i.e.

Simultaneous assessment of sources, processes, and factors influencing herbicide losses to surface waters in a small agricultural catchment.

To take appropriate measures to minimize agricultural herbicide inputs into surface waters, detailed knowledge is required about all the factors that control the losses of a given compound from point sources (i.e., farmyards) as well as from the diffuse sources (i.