Contaminants of emerging concern in the Hartbeespoort Dam catchment and the uMngeni River estuary 2016 pollution incident, South Africa

Cornelius Rimayi; David Odusanya; Jana M Weiss; Jacob de Boer; Luke Chimuka

doi:10.1016/j.scitotenv.2018.01.263

Contaminants of emerging concern in the Hartbeespoort Dam catchment and the uMngeni River estuary 2016 pollution incident, South Africa

Sci Total Environ. 2018 Jun 15:627:1008-1017. doi: 10.1016/j.scitotenv.2018.01.263. Epub 2018 Feb 3.

Authors

Cornelius Rimayi¹, David Odusanya², Jana M Weiss³, Jacob de Boer⁴, Luke Chimuka⁵

Affiliations

¹ Department of Water and Sanitation, Resource Quality Information Services (RQIS), Roodeplaat, P. Bag X313, 0001 Pretoria, South Africa; Vrije Universiteit Amsterdam, Environment and Health, De Boelelaan 1108, 1081 HZ Amsterdam, The Netherlands; University of the Witwatersrand, School of Chemistry, P. Bag 3, Wits, 2050 Johannesburg, South Africa. Electronic address: rimayic@dws.gov.za.
² Department of Water and Sanitation, Resource Quality Information Services (RQIS), Roodeplaat, P. Bag X313, 0001 Pretoria, South Africa.
³ Department of Environmental Science and Analytical Chemistry, Stockholm University, Arrhenius Laboratory, 10691 Stockholm, Sweden; Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences, Box 7050, 750 07 Uppsala, Sweden.
⁴ Vrije Universiteit Amsterdam, Environment and Health, De Boelelaan 1108, 1081 HZ Amsterdam, The Netherlands.
⁵ University of the Witwatersrand, School of Chemistry, P. Bag 3, Wits, 2050 Johannesburg, South Africa.

PMID: 29426120
DOI: 10.1016/j.scitotenv.2018.01.263

Abstract

A quantitative assessment of pollutants of emerging concern in the Hartbeespoort Dam catchment area was conducted using liquid chromatography-tandem mass spectrometry (LC-MS/MS) to establish the occurrence, source and distribution of 15 environmental pollutants, including 10 pharmaceuticals, 1 pesticide and 4 steroid hormones. Seasonal sampling was conducted in the Hartbeespoort Lake using sub-surface grab sampling to determine the lake's ecological status and obtain data for establishment of progressive operational monitoring. The Jukskei River, which lies upstream of the Hartbeespoort Dam, was sampled in the winter season. Five year old carp (Cyprinus carpio) and catfish (Clarias gariepinus) were also sampled from the Hartbeespoort Dam to study bioaccumulation in biota as well as to estimate risk associated with fish consumption. In the Jukskei River, the main source of 11 emerging pollutants (EPs) was identified as raw sewage overflow, with the highest ∑11 EP concentration of 593ngL^-1 being recorded at the Midrand point and the lowest ∑11 EP concentration of 164ngL^-1 at the N14 site located 1km downstream of a large wastewater treatment plant. The Jukskei River was found to be the largest contributor of the emerging contaminants detected in the Hartbeespoort Dam. In the Hartbeespoort Dam EP concentrations were generally in the order efavirenz>nevirapine>carbamazepine>methocarbamol>bromacil>venlafaxine. Water and sediment were sampled from the uMngeni River estuary within 24h after large volumes of an assortment of pharmaceutical waste had been discovered to be washed into the river estuary after flash rainfall on 18 May 2016. Analytical results revealed high levels of some emerging pollutants in sediment samples, up to 81ngg^-1 for nevirapine and 4ngg^-1 for etilefrine HCL. This study shows that efavirenz, nevirapine, carbamazepine, methocarbamol, bromacil and venlafaxine are contaminants that require operational monitoring in South African urban waters.

Keywords: Antiretroviral (ARV) drugs; Emerging pollutants (EPs); Hartbeespoort Dam; uMngeni River estuary.