Occurrence of selected endocrine disrupting compounds in the eastern cape province of South Africa

Abstract

Endocrine-disrupting compounds are attracting attention worldwide because of their effects on living things in the environment. Ten endocrine disrupting compounds: 4-nonylphenol, 2,4-dichlorophenol, estrone, 17β-estradiol, bisphenol A, 4-tertoctylphenol, triclosan, atrazine, imidazole and 1,2,4-triazole were investigated in four rivers and wastewater treatment plants in this study. Rivers were sampled at upstream, midstream and downstream reaches, while the influent and effluent samples of wastewater were collected from treatment plants near the receiving rivers. Sample waters were freeze-dried followed by extraction of the organic content and purification by solid-phase extraction. Concentrations of the compounds in the samples were determined with ultra-high performance liquid chromatography-tandem mass spectrometry. The instrument was operated in the positive electrospray ionization (ESI) mode. The results showed that these compounds are present in the samples with nonylphenol > dichlorophenol > bisphenol A > triclosan > octylphenol > imidazole > atrazine > triazole > estrone > estradiol. Nonylphenol has its highest concentration of 6.72 μg/L in King Williams Town wastewater influent and 2.55 μg/L in midstream Bloukrans River. Dichlorophenol has its highest concentration in Alice wastewater influent with 2.20 μg/L, while it was 0.737 μg/L in midstream Bloukrans River. Uitenhage wastewater effluent has bisphenol A concentration of 1.684 μg/L while it was 0.477 μg/L in the downstream samples of the Bloukrans River. Generally, the upstream samples of the rivers had lesser concentrations of the compounds. The wastewater treatment plants were not able to achieve total removal of the compounds in the wastewater while runoffs and wastes dump from the cities contributed to the concentrations of the compounds in the rivers.

Placental transfer of pesticides studied in human placental perfusion

“…The common metabolite, 1,2,4‐triazole, of propiconazole and bitertanol, 46 and the cypermethrin metabolite, 3‐PBA, were all detected, and their concentrations increased over time. 1,2,4‐triazole is classified as an EDC 46,47 and suspected to be toxic to reproduction. The common pyrethroid metabolite, 3‐PBA, exhibits anti‐oestrogenic activity in vitro, 48 and anti‐androgen activity 49 .…”

Emerging contaminant exposure to aquatic systems in the Southern African Development Community

“…The analysis of water samples in most of these studies was carried out with (or with the assistance of) collaborators in high‐income countries such as the United States (Bartsch et al, 2019 ; Mladenov et al, 2014 ), Switzerland (Curchod et al, 2020 ), and Italy (Ricolfi et al, 2020 ), highlighting the importance of international collaborations as well as a general lack of environmental analytical laboratories in the SADC region (K'oreje et al, 2012 ). South Africa is the exception, as evidenced by the emergence of locally produced data (Clement et al, 2019 ; Farounbi, 2020 ; Wanda et al, 2017 ). Most countries have focused on inorganic ions (Figure 1 ) such as sulfur, copper, and iron—again with the exception of South Africa.…”

Community of Practice as a teaching approach in a postgraduate environment. An insider ethnography of a higher education institution in South Africa

“…The permeable boundary of the EHB macro-assemblage has allowed consecutive members of this community of practice to enter the platform, participate in the creation of micro-assemblages and the distributive agency has resulted in the growth of the research group. Micro-assemblages inside EHB have to the development of the new research directions beyond the original focus on water quality and sanitation (Vumazonke et al, 2020;Farounbi and Ngqwala, 2021). There have been several core members, who I still work with closely and who have maintained continuity of fundamental epistemic authority inside the EHB, the macro-assemblage.…”