IMPACT OF PHARMACEUTICALS ON ALGAL SPECIES

Trace amounts of activated pharmaceutical ingredients (APIs) have been reported in aquatic environments worldwide, and their toxicity to non-target organisms is of increasing concern. Algae are primary producers in aquatic food chains, and as such are very sensitive to external disturbance. The understanding of the adverse effects on the algal species such as growth and physiological effects is vital to understand the risks of APIs in the aquatic environment. This thesis therefore describes desk-based studies and a series of laboratory experiments to characterise the risk of APIs, and to investigate the effects of APIs on a wide range of algal species.
In the desk-study, a review summarising the available ecotoxicological data of APIs to algal species was initially performed, where differences in the sensitivity of the algal species towards API exposures were found. After that, an approach for prioritising APIs and associated metabolites in the UK environment was developed, where three major-use antibiotics lincomycin, tylosin and trimethoprim that pose a potential threat to algal species in the natural environment were identified for further experimental investigation. Laboratory experiments were then conducted to investigate the effects of three antibiotics on the growth and physiology of a range of algal species from chlorophytes, cyanobacteria and diatoms. Risk arising from the antibiotic mixture in the European surface waters was characterised
In conclusion three major-use antibiotics could cause inhibitory effects on both algal growth and physiology. At environmentally relevant concentrations the antibiotic mixtures can pose potential risks in European surface waters.