Application of the Chemcatcher passive samplers and yeast-based reporter bioassay for estrogenic activity screening of surface waters from the area of intensive livestock farming in Poland

Abstract

Emerging contaminants such as estrogenic endocrine-disrupting compounds are important environmental issue due to their potential adverse effects on humans and ecosystems [1]. Complex mixtures of these substances when released into the environment may account for their combined toxic effects in living organisms. As intensive livestock farming is associated with the use of biocides and veterinary drugs, this study aimed to assess the estrogenic activity of surface waters from four sites in the area of intensive livestock farming in Poland with the use of Chemcatcher passive samplers in combination with in vitro yeastbased bioassay. Four sampling sites were selected close to the intensive livestock farming (A-cattle breeding, B-cattle and poultry farms, C-pig farming, D–pedigree piggery). The samples were taken during spring, summer, and autumn. Two configurations of Chemcatcher passive samplers were used: HLB-L disks with PES membranes (polar configuration) and C18 disks with LDPE diffusion membrane (non-polar configuration). Samplers were deployed in water for 14 days. Following exposure, samplers were rinsed, and stored frozen until processing. The extraction from HLB-L disks was performed with methanol and ultra-pure water as described by Robinson et al. [2], whereas C18 disks were extracted with acetone and acetone:hexane (1:1 v/v) using ultrasonication, as described by Kuster et al. [3]. Estrogenic activity of the extracts were assessed using in vitro yeast reporter gene bioassay, performed as previously described [4]. The extracts were tested in triplicate, the estrogenicities of the samples were expressed in ng 17β-estradiol equivalents (ng EEQ/sampler). The estrogenicity of extracts from polar configuration ranged between 11 and 30 ng EEQ/sampler. The highest estrogenic activities were found at site B, and the lowest was found for site A. As for the seasonal variation, the estrogenic activity was highest in spring (site B), the lowest in autumn (site A). Estrogenicity from non-polar configuration was not detected except low estrogenic activity of 8 and 10 ng EEQ/sampler in two samples from sites B (spring) and C (summer), respectively. The higher estrogenic activity measured for polar configuration reflects the fact that most estrogenic compounds are polar or semi-polar with octanol-water partition coefficients (log Kow) <4. The use of in vitro bioassays is important for the evaluation of the estrogenic potency of surface waters. The combination of passive sampling and in vitro assay allowed for the assessment of estrogenic activity over a long period (14 days). This gives a better picture of exposure levels and reduces the error caused by short-term measurements. The polar configuration of Chemcatcher was more effective in estrogenic activity screening.