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Ecological risk modelling of antiretroviral drugs in the aquatic environment

Dissertation (MSc (Applied Science) Water Utilisation)--University of Pretoria, 2022.

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Other Authors: Musee, Ndeke
Format: Thesis
Language:English
Published: University of Pretoria 2022
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access_status_str Open Access
author2 Musee, Ndeke
author_browse Musee, Ndeke
author_facet Musee, Ndeke
collection Thesis
dc_rights_str_mv © 2022 University of Pretoria. All rights reserved. The copyright in this work vests in the University of Pretoria. No part of this work may be reproduced or transmitted in any form or by any means, without the prior written permission of the University of Pretoria.
description Dissertation (MSc (Applied Science) Water Utilisation)--University of Pretoria, 2022.
format Thesis
id oai:repository.up.ac.za:2263/86669
institution University of Pretoria (South Africa)
language English
last_indexed 2026-06-10T12:36:22.373Z
license_str Other — see source repository
provenance_str_mv Harvested via OAI-PMH from UPSpace — University of Pretoria Institutional Repository
publishDate 2022
publishDateRange 2022
publishDateSort 2022
publisher University of Pretoria
publisherStr University of Pretoria
record_format dspace
source_str UPSpace — University of Pretoria Institutional Repository
spelling oai:repository.up.ac.za:2263/86669 Ecological risk modelling of antiretroviral drugs in the aquatic environment Musee, Ndeke u16252642@tuks.co.za Ngwenya, Phephile Aquatic organisms Risk quotient Predicted environmental concentration Measured environmental concentration Ecological Structure Activity Relationships Antiretroviral drugs Material flow analysis UCTD Dissertation (MSc (Applied Science) Water Utilisation)--University of Pretoria, 2022. The success of antiretroviral therapy (ART) programme's on the management of the Human Immunodeficiency Virus/ Acquired Immunodeficiency Syndrome (HIV/AIDS) in the Sub-Saharan African (SSA) region has inadvertently led to the release of antiretroviral drugs (ARVs) into the environment. This study aimed to model the quantities and risks of ARVs in aquatic environments. Herein, the ecological risks of first regime (efavirenz (EFV), lamivudine (3TC), nevirapine (NVP), zidovudine (AZT) and tenofovir (TDF)), and second regime ARVs (lopinavir (LPV), atazanavir (ATV), ritonavir (RTV), didanosine (DDI) and dolutegravir (DTG)) were investigated. ARV releases and quantification into the aquatic environment were based on Eswatini as a study case country using the material flow analysis (MFA) approach. Quantities of ARVs into the environment were estimated for all ten drugs using the input model parameters, viz.: (number of people living with HIV (PLWHIV), number of people on ARVs, drug dosages, treatment adherence and drug excretion rate). The predicted environmental concentrations (PEC) were then compared to the predicted no effect concentrations (PNEC) to estimate the possible risk (by deriving the risk quotient (RQ). Owing to the dearth of ecotoxicological data for ARVs, Ecological Structure Activity Relationships (ECOSAR) was used to derive the toxicity of each drug for three species: daphnia, algae, and fish. Results indicated quantities of ARVs were three-fold higher in surface water relative to wastewater. For example, in 2017, EFV was 5 671 and 1 853 kg in surface water and wastewater, respectively. Higher flows of ARVs in surface waters were associated with a lack of sanitation services for most Eswatini population, and low wastewater treatment plant (WWTP) performance. Results further showed wide variability of PECs in surface water (0.08–73.2 μg/L) and wastewater (0.02 – 23.1 μg/L). Of the ten ARVs, the risk of DTG was unquantifiable due to a lack of ecotoxicity data even when using the ECOSAR approach. Only DDI had RQs < 1 for all three trophic levels in surface water, whereas EFV, LPV, and RTV posed the highest risk (RQ >10) to all three taxa. Further, NVP and AZT presented moderate risk (1 < RQ < 10) to algae, and 3TC and TDF posed minimal risk (RQ < 1) to daphnia. No risk for the ARVs was estimated in wastewater except for TDF due to the lack of their bacterial toxicity data. Results herein make it possible for the first time to quantify the potential environmental risks of ARVs using a modelling approach. The model can be extended to other SSA countries given their limited capabilities to detect and quantify ARVs risks in the environment using costly analytical techniques. Furthermore, the results suggest lack of sanitation services and high HIV/AIDs prevalence in SSA with concomitant high concentrations of ARVs in the environment potentially may trigger antiretroviral drug resistance, with possible negative implications to the ART programme. Chemical Engineering MSc (Applied Science) Water Utilisation Unrestricted 2022-08-03T09:14:26Z 2022-08-03T09:14:26Z 2022-09-07 2022 Dissertation * S2022 https://repository.up.ac.za/handle/2263/86669 en © 2022 University of Pretoria. All rights reserved. The copyright in this work vests in the University of Pretoria. No part of this work may be reproduced or transmitted in any form or by any means, without the prior written permission of the University of Pretoria. application/pdf University of Pretoria
spellingShingle Aquatic organisms
Risk quotient
Predicted environmental concentration
Measured environmental concentration
Ecological Structure Activity Relationships
Antiretroviral drugs
Material flow analysis
UCTD
Ecological risk modelling of antiretroviral drugs in the aquatic environment
title Ecological risk modelling of antiretroviral drugs in the aquatic environment
title_full Ecological risk modelling of antiretroviral drugs in the aquatic environment
title_fullStr Ecological risk modelling of antiretroviral drugs in the aquatic environment
title_full_unstemmed Ecological risk modelling of antiretroviral drugs in the aquatic environment
title_short Ecological risk modelling of antiretroviral drugs in the aquatic environment
title_sort ecological risk modelling of antiretroviral drugs in the aquatic environment
topic Aquatic organisms
Risk quotient
Predicted environmental concentration
Measured environmental concentration
Ecological Structure Activity Relationships
Antiretroviral drugs
Material flow analysis
UCTD
url https://repository.up.ac.za/handle/2263/86669