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Faulstich L, Wollenweber S, Reinhardt-Imjela C, Arendt R, Schulte A, Hollert H, Schiwy S. Ecotoxicological evaluation of surface waters in Northern Namibia. ENVIRONMENTAL MONITORING AND ASSESSMENT 2024; 196:456. [PMID: 38630192 PMCID: PMC11024038 DOI: 10.1007/s10661-024-12613-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/17/2023] [Accepted: 04/04/2024] [Indexed: 04/19/2024]
Abstract
The increasing pressure on freshwater systems due to intensive anthropogenic use is a big challenge in central-northern Namibia and its catchment areas, the Kunene and the Kavango Rivers, and the Cuvelai-Etosha Basin, that provide water for more than 1 million people. So far, there is no comprehensive knowledge about the ecological status and only few knowledge about the water quality. Therefore, it is crucial to learn about the state of the ecosystem and the ecological effects of pollutants to ensure the safe use of these resources. The surface waters of the three systems were sampled, and three bioassays were applied on three trophic levels: algae, daphnia, and zebrafish embryos. Additionally, in vitro assays were performed to analyze mutagenicity (Ames fluctuation), dioxin-like potential (micro-EROD), and estrogenicity (YES) by mechanism-specific effects. The results show that acute toxicity to fish embryos and daphnia has mainly been detected at all sites in the three catchment areas. The systems differ significantly from each other, with the sites in the Iishana system showing the highest acute toxicity. At the cellular level, only weak effects were identified, although these were stronger in the Iishana system than in the two perennial systems. Algae growth was not inhibited, and no cytotoxic effects could be detected in any of the samples. Mutagenic effects and an estrogenic potential were detected at three sites in the Iishana system. These findings are critical in water resource management as the effects can adversely impact the health of aquatic ecosystems and the organisms within them.
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Affiliation(s)
- L Faulstich
- Freie Universität Berlin, Berlin, Germany.
- Goethe-Universität Frankfurt, Frankfurt, Germany.
| | | | | | - R Arendt
- Freie Universität Berlin, Berlin, Germany
| | - A Schulte
- Freie Universität Berlin, Berlin, Germany
| | - H Hollert
- Goethe-Universität Frankfurt, Frankfurt, Germany
| | - S Schiwy
- Goethe-Universität Frankfurt, Frankfurt, Germany
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Zheng S, Sheng F, Gu C, Li Y, Fang Z, Luo J. DGT method for the in situ measurement of triazines and the desorption kinetics of atrazine in soil. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2023; 30:51061-51074. [PMID: 36807020 DOI: 10.1007/s11356-023-25985-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/24/2022] [Accepted: 02/13/2023] [Indexed: 04/16/2023]
Abstract
Triazines are frequently detected in nature water and agricultural soils worldwide. They are considered harmful to plants, animals, and the human health. In this study, diffusive gradients in thin films (DGT) method was developed for the assessment of several triazines. DGT device was used for the in situ measurement of atrazine in a pesticide factory and obtained reliable data. The atrazine concentrations measured by DGT, and solvent extraction method was in a constant ratio. The DIFS model was coupled with DGT technique to study the desorption kinetics of atrazine in four kinds of different soils. The yellow-brown soil was more inclined to adsorb atrazine than other three soils. 2_D DIFS model was used to obtain the partition coefficient for labile atrazine (Kdl), the values of the response time (Tc), and desorption/adsorption rates (k1 and k-1). The yellow-brown soil has a larger labile pool size, and a faster resupply speed of atrazine. The 1_D DIFS model was used to simulate the profiles of atrazine concentrations in soil solution and solid phase. The results show that the desorption of atrazine in soil was limited by kinetic limitation at short time, and was limited by the solid phase reservoir at long time.
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Affiliation(s)
- Siheng Zheng
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, Jiangsu, 210023, People's Republic of China
| | - Feng Sheng
- State Environmental Protection Key Laboratory of Soil Environmental Management and Pollution Control, Ministry of Ecology and Environment, Nanjing Institute of Environmental Sciences, Nanjing, 210042, People's Republic of China
| | - Cheng Gu
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, Jiangsu, 210023, People's Republic of China
| | - Yanying Li
- College of Environmental Science and Engineering, Dalian Maritime University, No 1 Linghai Road, Dalian, Liaoning, 116026, People's Republic of China
| | - Zhou Fang
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, Jiangsu, 210023, People's Republic of China.
| | - Jun Luo
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, Jiangsu, 210023, People's Republic of China
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Steffen HC, Smith K, van Deventer C, Weiskerger C, Bosch C, Brandão J, Wolfaardt G, Botha A. Health risk posed by direct ingestion of yeasts from polluted river water. WATER RESEARCH 2023; 231:119599. [PMID: 36645944 DOI: 10.1016/j.watres.2023.119599] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/16/2022] [Revised: 01/07/2023] [Accepted: 01/09/2023] [Indexed: 06/17/2023]
Abstract
River water is an essential human resource that may be contaminated with hazardous microorganisms. However, the risk of yeast infection through river water exposure is unclear because it is highly dependant on individual susceptibility and has therefore not been well-studied, to date. To evaluate this undefined risk, we analysed the fungal communities in less polluted (LP) and highly polluted (HP) river water, as determined using principal coordinate analysis of pollution indicators. We enumerated culturable yeasts using a thermally selective isolation procedure (37 °C) and thus promoted the growth of potentially opportunistic species. Yeast species identified as clinically relevant were then tested for antifungal resistance. In addition, we propose a quantitative microbial risk assessment (QMRA) framework to quantitatively assess the potential risk of yeast infection. Our results indicated that pollution levels significantly altered fungal communities (p = 0.007) and that genera representing opportunistic and pathogenic members were significantly more abundant in HP waters (p = 0.038). Additionally, the yeast species Candida glabrata and Clavispora lusitaniae positively correlated with other pollution indicators, demonstrating the species' indicator potential. Our QMRA results further indicate that higher risk of infection is associated with increased water pollution levels (considering both physicochemical and bacterial indicators). Furthermore, yeast species with higher pathogenic potential present an increased risk of infection despite lower observed concentrations in the river water. Interestingly, the bloom of Meyerozyma guilliermondii during the wet season suggests that other environmental factors, such as dissolved oxygen levels and water turbulence, might affect growth characteristics of yeasts in river water, which consequently affects the distribution of annual infection risks. The presence of antifungal resistant yeasts, observed in this study, could further contribute to variation in risk distribution. Research on the ecophysiology of yeasts in these environments is therefore necessary to ameliorate the uncertainty and sensitivity of the proposed QMRA model. In addition to the vital knowledge on opportunistic and pathogenic yeast occurrence in river water and their observed association with pollution, this study provides valuable methods and insights to initiate future QMRAs of yeast infections.
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Affiliation(s)
- Heidi Christa Steffen
- Department of Microbiology, University of Stellenbosch, Stellenbosch, Western Cape 7600, South Africa
| | - Katrin Smith
- Department of Microbiology, University of Stellenbosch, Stellenbosch, Western Cape 7600, South Africa
| | - Corné van Deventer
- Department of Microbiology, University of Stellenbosch, Stellenbosch, Western Cape 7600, South Africa
| | - Chelsea Weiskerger
- Department of Civil and Environmental Engineering, Michigan State University, East Lansing, MI 48824, United States
| | - Caylin Bosch
- Department of Microbiology, University of Stellenbosch, Stellenbosch, Western Cape 7600, South Africa
| | - João Brandão
- Department of Environmental Health, National Institute of Health Doctor Ricardo Jorge, Av. Padre Cruz, Lisbon 1649-016, Portugal; Centre for Environmental and Marine Studies (CESAM), Department of Animal Biology, University of Lisbon, Campo Grande, Lisbon 1749-016, Portugal
| | - Gideon Wolfaardt
- Department of Microbiology, University of Stellenbosch, Stellenbosch, Western Cape 7600, South Africa
| | - Alfred Botha
- Department of Microbiology, University of Stellenbosch, Stellenbosch, Western Cape 7600, South Africa.
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