SinS - Abstract

Abstract Information :

Combination of passive sampling, targeted analysis and suspect screening to assess the occurrence and distribution of polar organic chemicals in two chalk streams in Hampshire, UK
Rosamund, F. A. Robinson1; Graham, A. Mills2; Roman Grabic3; Adam Bořík3; Gary R. Fones1

1School of Earth and Environmental Science, University of Portsmouth, Burnaby Road, Portsmouth PO1 3QL, United Kingdom
2School of Pharmacy and Biomedical Sciences, University of Portsmouth, White Swan Road, Portsmouth, PO1 2DT, United Kingdom
3Faculty of Fisheries and Protection of Water, University of South Bohemia in České Budějovice, Zátiší 728/11, Vodňany, Czech Republic, 389 25

Exposure to polar contaminants such as pesticides, pharmaceuticals and personal care products is a threat to freshwater ecosystems and their biodiversity. The aim of this study was to assess the occurrence and distribution of polar organic chemicals in two chalk streams (River Itchen and Test) in Hampshire, UK and to assess the impact of these chemicals on the observed decline of macroinvertebrates.

Sampling was undertaken at 17 sites were where macroinvertebrate monitoring had taken place since 1991. Chemcatcher passive samplers were deployed for two 14-day periods in the autumn, winter, spring and summer of 2022. The Chemcatcher configuration was an HLB-L receiving phase disk overlain by a polyethersulfone membrane (0.2 µm pore size). In addition, discrete water samples (1 L) were collected

After exposure the HLB-L sampler disks were eluted using methanol (40 mL) and then concentrated. Similarly, water samples were also extracted using a HLB-L disk. The extracts were analysed with a high-resolution LC/MS (Q-Exactive hybrid orbital instrument). The data were processed by TraceFinder 4.1 software, and the concentration of target analytes calculated using isotopically labelled internal standards and matrix matching standard approaches. A total of 169 Chemcatcher extracts, and 119 water samples were analysed. To determine the concentration (ng L-1) of each compound sequestered by the Chemcatcher a generic sampling rate (Rs) of 0.047 L d-1 (Römerscheid, M. et al., (2023) was applied.

Fewer pesticides (16%) and pharmaceuticals (2%) were detected in the water than in the Chemcatcher. The herbicides atrazine (plus its transformation product desethyl atrazine), simazine and hydroxyl-terbuthylazine were ubiquitous pollutants but varied in concentration (0.3 to 18 ng L-1). The sites with the greatest number of different pesticides changed throughout the year; but sites with the highest concentrations were always those affected by wastewater treatment plants.

Two pharmaceuticals, lamotrigine (82%) and carbamazepine (80%) were the most commonly detected. Concentrations varied between (0.2-304 ng L-1) and (0.3-119 ng L-1) respectively. The sites with the greatest number of different pharmaceuticals were those affected by wastewater.

Our analytical data can be combined with macroinvertebrate sampling to access the impact on biodiversity. The data may also guide future monitoring campaigns and help direct mitigation strategies within the catchment.

Reference: Römerscheid, M., Paschke, A., Schneider, S. Blaha, M., Harzdorf, J., Schüürmann, G. (2023). Calibration of the Chemcatcher® passive sampler and derivation of generic sampling rates for a broad application in monitoring of surface waters. Science of the Total Environment. 871:161936 https://doi.org/j.scitotenv.2023.161936