Analysis, occurrence, fate and effects of flubendazole in moorland river catchments

Moorland areas are very important worldwide and are found, for example, in the British Isles, Russia, Canada, Scandinavia, New Zealand, Tasmania, Japan and South America (Holden et al., 2007). The need to conserve these environments is exemplified by the fact that many have been given national and international conservation designations to protect habitats and priority species. In addition to biodiversity, they are internationally important for water supply, carbon storage, agriculture, forestry and tourism (Thompson et al., 1995; Holden et al., 2007; Curtis et al., 2014). Red grouse sport shooting is regularly practiced on moorlands and man-made chemicals have been used increasingly on grouse moors since the mid-1980s to maintain grouse populations because parasitic nematode worms (Trichostrongylus tenuis) reduce both breeding success and adult survival. This is done either via medicated grit or dosing of captured birds (Newborn and Foster, 2002). The use of grit containing the anthelmintic (worming) chemical flubendazole is widespread (Ceballos et al., 2012) and its addition to moorlands for grouse to eat (Figure 1) may release flubendazole into the environment as could excretion of unabsorbed residues by the birds; 50 % of the administered dose is excreted unchanged (Kreuzig et al., 2007; Weiss et al., 2008). The potential impacts of these residues on the environment are currently unstudied (Watson and Moss, 2008; Davies et al., 2016; Thompson et al., 2016; Sotherton et al., 2017).


This project will provide robust data describing the presence, fate and effects of flubendazole in moorland catchments. Only a few previous studies have attempted to measure flubendazole in the environment (e.g. Kreuzig et al., 2007) and none of these have dealt with organic-rich moorland soils and water which pose particular analytical challenges given that the peat and organomineral soils found on moorlands are excellent adsorbents of organic compounds. The increased levels of organic matter limit extractability and it is necessary to remove naturally occurring organic molecules like lignins, pigments and phenols in order to reduce interferences during analysis. We have already found that molecularly imprinted polymers (MIPs) work better than commercially available extraction cartridges for analysing flubendazole. MIPs have previously proved to be very valuable for the selective extraction of test substances from samples (Horvat et al., 2012). This project will optimise the MIP for selectivity, binding strength and capacity and transfer the analytical method to our recently purchased Liquid Chromatography-Time of Flight-Mass Spectrometry (LC-TOF-MS) instrument, which should afford further increases in sensitivity. The method produced would be the state of the art for analysis of flubendazole (and other anthelmintics) in organic-rich environments. The method will be used to analyse soil and water samples collected across moorland environments for flubendazole and in controlled fate experiments. Effects experiments will be undertaken on soil mesofauna and freshwater invertebrates.
Objectives:
The overall aim of the project is to understand whether the use of flubendazole to medicate grouse in moorland catchments is leading to the presence of this emerging pollutant in soil and water. The specific objectives are to:
1. Improve the analysis of flubendazole in moorland soils and water using molecularly imprinted polymers
2. Measure the occurrence of flubendazole in moorland soils and water
3. Determine the fate of flubendazole in moorland catchments
4. Assess the potential effects of flubendazole on relevant organisms