RT doctoral thesis
T1 Ecotoxicological assessment of galaxolide and tonalide as contaminants of emerging concern in marine ecosystems
A1 Ehiguese, Friday Ojie
A2 Química Física
K1 Ecotoxicological assessment
K1 Biomarker
K1 Avoidance behaviour
K1 Population immediate decline
K1 Environmental risk assessment
K1 Marine ecosystems
K1 Neuroendocrine disruption
K1 Acute toxicity
K1 Chronic toxicity
K1 Bioassays
K1 Oxidative stress
K1 Genotoxicity
K1 Fragrances
K1 Polycyclic musk compounds
K1 Galaxolide and tonalide
K1 Neurotoxicity
K1 Marine organisms
AB The polycyclic musk compounds Galaxolide (HHCB) and Tonalide (AHTN) are the most frequentlyconsumed fragrance materials applied in many household and personal care products. These substanceshave been detected in all environmental compartments and, due to their inherent lipophilicity, they easilybioaccumulate in aquatic organism. The aim of this PhD thesis was to assess the risk of environmentalconcentrations of HHCB and AHTN in the marine environments. In order to provide a more completeassessment on marine biota, empirical approach based on data of ecotoxicological assays was exploredbased on environmental risk assessment (ERA) scheme. In this case, it was intended to employ organismsfrom different trophic levels like microalgae, echinoderms, bivalves, shrimps, and fish. This diversificationin the species allows assessing how organisms with different biological complexity can be affected. Inaddition, different endpoints were used for each species, taking as basis the sensitivity and relevance of the endpoints. Another important aspect considered to select the endpoints was their level of biologicalorganization, so that the responses measured were based on acute and chronic exposure, focusing ongrowth, survival, development, behaviour, and biomarkers at the biochemical and molecular levels.The results obtained in this thesis show that environmental concentrations of both compounds aredetrimental to microalgae growth posing significant risk to Phaeodactylum tricornutum and Isochrysisgalbana. It was also observed that environmental concentrations of HHCB and AHTN significantly alteredthe early life stages endpoints such as fertilization, larval development, and survival in tested species.Furthermore, this thesis has proven that in a scenario of heterogenous pollution where lethality is notexpected to occur, HHCB and AHTN may trigger spatial avoidance, which might reduce the localbiodiversity of ecosystems due to emigration to safer environments. Sublethal effects assessed in bivalvesafter chronic exposure to HHCB and AHTN showed that these substances are bioavailable to marineorganisms and they have the potential to induce oxidative stress, genotoxicity, neurotoxicity and alter thehealth status of marine organisms. It was also observed that both compounds modulated endocrinedisruption biomarkers in small fish. Despite the significant alterations in endocrine disruption biomarkersinduced by both compounds, AHTN appeared to be a more potent inhibitor of endocrine activity in themarine environments.This PhD Thesis has demonstrated the adverse effects of environmental concentrations of HHCB andAHTN in marine ecosystems. Therefore, the data presented in this study should be integrated with otheravailable data required for policy actions that will aid the conservation and management of the sea.
YR 2021
FD 2021-07-14
LK http://hdl.handle.net/10498/25585
UL http://hdl.handle.net/10498/25585
LA eng
DS Repositorio Institucional de la Universidad de Cádiz
RD 05-nov-2026