BACKGROUND

Global contamination of soil and aquatic ecosystems by pharmaceutical and microbiological pollutants (such as antimicrobial-resistant microorganisms and/or pathogens) raises severe concerns about impacts on ecosystem health and repercussions on humans and animals. Preserving ecosystems from adverse ecotoxicological effects of pharmaceuticals and their transformation products, and limiting the environmental spread of antimicrobial resistance and pathogens is imperative to reach several UN Sustainable Development Goals as well as the European Green Deal, Water Framework Directive and Biodiversity Strategy for 2030. In this context, the main scientific objective of Pharm-ERA is to develop and implement innovative concepts, methods and strategies to improve the monitoring and assessment of the environmental effects and risks of pharmaceuticals, their transformation products, antimicrobial resistances and pathogens from terrestrial to aquatic environments. The ultimate goal is to provide scientific evidence and expertise to contribute to reducing the environmental spread and impact of these chemical and microbiological contaminants and to preserve microbial diversity and functions across the soil-water-sediment continuum.

DESCRIPTION OF THE PhD PROJECT

Aquatic ecosystems are continuously exposed to complex mixtures of organic contaminants, such as pharmaceuticals, which gives rise to concern for potential risks for ecological and human health even at the trace level. To address the complexity of mixtures of Contaminants of Emerging Concern (CECs) present in environmental waters, Effect-Directed Analysis (EDA) is a cutting-edge approach. EDA combines biological activity testing and stepwise fractionation with chemical analysis to prioritize biologically active CECs in environmental matrices. Despite its broad use in environmental monitoring, such an approach still lacks ecological relevance since most of bioassays focus on specific in vitro endpoints. To tackle this gap, aquatic microbial communities (i.e. biofilms) are a complex consortium of autotrophic and heterotrophic organisms, particularly sensitive to multiple environmental stressors and chemical contamination. In particular periphytic biofilms are widely used in ecotoxicological assessment as biomonitoring systems for detection of exposure to toxicants and associated ecological effects on aquatic ecosystems. A multi-biomarker approach can be used for the detection of effects of chemicals -or mixtures of them- on biofilms, ranging from structural to functional-based descriptors.
In this context, this PhD project aims to develop and validate an innovative approach for Effect Directed Analysis (EDA) based on responses of natural freshwater biofilms for the identification of CECs potentially leading to ecological impairment. The PhD student will join the Environmental and Water Chemistry for Human Health (ONHEALTH) Research group at the IDAEA-CSIC (Spain). The fellow will develop and implement:
1- Solid Phase Extraction (SPE) vs (Ultra)High-Performance Liquid Chromatography (UHPLC) based Fractionation
2- miniaturized periphyton-based bioassays to assess structural and functional response,
3- UHPLC coupled to High Resolution Mass Spectrometry (UHPLC-HRMS). In addition, the PhD student will have a hand-on cutting-edge HRMS-based untargeted metabolomics approach and will get experience on regulatory bioassay testing on single organisms including bacteria and algae.