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Sub-chronic toxicity of environmentally relevant atrazine concentrations on exposed tadpoles and adult male African clawed frogs (Xenopus laevis) was evaluated in a quality controlled laboratory for 90 days. The aim of this study was to determine the effects of atrazine on the survival, growth and gonad development of African clawed frogs. After exposure of tadpoles to atrazine concentrations of 0 (control), 0.01, 200 and 500 μg L−1 in water, mortality rates of 0, 0, 3.3 and 70% respectively were recorded for the 90 day exposure period. Morphometry showed significantly reduced tadpole mass in the 500 μg L−1 atrazine exposed tadpoles (p < 0.05). Light microscopy on testes of adult frogs exposed to the same atrazine concentrations using hematoxylin and eosin (H&E) and Van Gieson staining techniques revealed gonadal atrophy, disruption of germ cell lines, seminiferous tubule structure damage and formation of extensive connective tissue around seminiferous tubules of frogs exposed to 200 μg L−1 and 500 μg L−1 atrazine concentrations. Ultrastructural analysis of the cellular organelles using transmission electron microscopy (TEM) revealed significant amounts of damaged mitochondria in testosterone producing Leydig cells as well as Sertoli cells. Biochemical analysis revealed reduced serum testosterone levels in adult frogs at all exposure levels as well as presence of six atrazine metabolites in frog serum and liver. The results indicate that atrazine concentrations greater than the calculated LC50 of 343.7 μg L−1 cause significant mortality in tadpoles, while concentrations ≥200 μg L−1 adversely affect reproductive health of adult frogs and development of tadpoles sub-chronically exposed to atrazine.

A quantitative assessment of pollutants of emerging concern in the Hartbeespoort Damcatchment 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 Sigma 11 EP concentration of 593 ng L-1 being recorded at the Midrand point and the lowest Sigma 11 EP concentration of 164 ng L-1 at the N14 site located 1 km 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 24 h after large volumes of an assortment of pharmaceuticalwaste had been discovered to bewashed 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 81 ng g(-1) for nevirapine and 4 ng g(-1) for etilefrine HCL. This study shows that efavirenz, nevirapine, carbamazepine, methocarbamol, bromacil and venlafaxine are contaminants that require operational monitoring

Seasonal variation of eight chloro-s-triazine herbicides and seven major atrazine and terbuthylazine degradation products was monitored in the Hartbeespoort Dam catchment using gas chromatography-mass spectrometry (GC-MS) and liquid chromatography-mass spectrometry (LC-MS/MS). Lake, river and groundwater were sampled from the Hartbeespoort Dam catchment over four seasons and the downstream Jukskei River was monitored during the winter season. Triazine herbicide concentrations in the Hartbeespoort Dam were in the order atrazine > simazine > propazine > ametryn > prometryn throughout the four seasons sampled. Triazine herbicide concentrations in the Hartbeespoort Dam surface water were highest in summer and gradually decreased in successive seasons of autumn, winter and spring. Terbuthylazine was the only triazine herbicide detected at all sampling sites in the Jukskei River, though atrazine recorded much higher concentrations for the N14 and Kyalami sites, with concentrations of 923 and 210 ng L-1 respectively, compared to 134 and 74 ng L-1 for terbuthylazine. Analytical results in conjunction with river flow data indicate that the Jukskei and Crocodile Rivers contribute the greatest triazine herbicide loads into the Hartbeespoort Dam. No triazine herbicides were detected in the fish muscle tested, showing that bioaccumulation of triazine herbicides is negligible. Atrazine and terbuthylazine metabolites were detected in the fish muscle with deethylatrazine (DEA) being detected in both catfish and carp muscle at low concentrations of 0.2 and 0.3 ng g(-1), respectively. Desethylterbuthylazine (DET) was detected only in catfish at a concentration of 0.3 ng g(-1). With atrazine herbicide groundwater concentrations being >130 ng L-1 for all seasons and groundwater Sigma triazine herbicide concentrations ranging between 527 and 367 ng L-1, triazine compounds in the Hartbeespoort Dam catchment may pose a risk to humans and wildlife in light findings of endocr

Sub-chronic toxicity of environmentally relevant atrazine concentrations on exposed tadpoles and adult male African clawed frogs (Xenopus laevis) was evaluated in a quality controlled laboratory for 90 days. The aim of this study was to determine the effects of atrazine on the survival, growth and gonad development of African clawed frogs. After exposure of tadpoles to atrazine concentrations of 0 (control), 0.01, 200 and 500 mu g L-1 in water, mortality rates of 0, 0, 3.3 and 70% respectively were recorded for the 90 day exposure period. Morphometry showed significantly reduced tadpole mass in the 500 mu g L-1 atrazine exposed tadpoles (p < 0.05). Light microscopy on testes of adult frogs exposed to the same atrazine concentrations using hematoxylin and eosin (H&E) and Van Gieson staining techniques revealed gonadal atrophy, disruption of germ cell lines, seminiferous tubule structure damage and formation of extensive connective tissue around seminiferous tubules of frogs exposed to 200 mu g L-1 and 500 mu g L-1 atrazine concentrations. Ultrastructural analysis of the cellular organelles using transmission electron microscopy (TEM) revealed significant amounts of damaged mitochondria in testosterone producing Leydig cells as well as Sertoli cells. Biochemical analysis revealed reduced serum testosterone levels in adult frogs at all exposure levels as well as presence of six atrazine metabolites in frog serum and liver. The results indicate that atrazine concentrations greater than the calculated LC50 of 343.7 mu g L-1 cause significant mortality in tadpoles, while concentrations >= 200 mu g L-1 adversely affect reproductive health of adult frogs and development of tadpoles sub-chronically exposed to atrazine.

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 593 ng L−1 being recorded at the Midrand point and the lowest ∑11 EP concentration of 164 ng L−1 at the N14 site located 1 km 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 24 h 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 81 ng g−1 for nevirapine and 4 ng g−1 for etilefrine HCL. This study shows that efavirenz, nevirapine, carbamazepine, methocarbamol, bromacil and venlafaxine are contamin

Seasonal variation of eight chloro-s-triazine herbicides and seven major atrazine and terbuthylazine degradation products was monitored in the Hartbeespoort Dam catchment using gas chromatography–mass spectrometry (GC–MS) and liquid chromatography-mass spectrometry (LC-MS/MS). Lake, river and groundwater were sampled from the Hartbeespoort Dam catchment over four seasons and the downstream Jukskei River was monitored during the winter season. Triazine herbicide concentrations in the Hartbeespoort Dam were in the order atrazine > simazine > propazine > ametryn > prometryn throughout the four seasons sampled. Triazine herbicide concentrations in the Hartbeespoort Dam surface water were highest in summer and gradually decreased in successive seasons of autumn, winter and spring. Terbuthylazine was the only triazine herbicide detected at all sampling sites in the Jukskei River, though atrazine recorded much higher concentrations for the N14 and Kyalami sites, with concentrations of 923 and 210 ng L− 1 respectively, compared to 134 and 74 ng L− 1 for terbuthylazine. Analytical results in conjunction with river flow data indicate that the Jukskei and Crocodile Rivers contribute the greatest triazine herbicide loads into the Hartbeespoort Dam. No triazine herbicides were detected in the fish muscle tested, showing that bioaccumulation of triazine herbicides is negligible. Atrazine and terbuthylazine metabolites were detected in the fish muscle with deethylatrazine (DEA) being detected in both catfish and carp muscle at low concentrations of 0.2 and 0.3 ng g− 1, respectively. Desethylterbuthylazine (DET) was detected only in catfish at a concentration of 0.3 ng g− 1. With atrazine herbicide groundwater concentrations being > 130 ng L− 1 for all seasons and groundwater ∑ triazine herbicide concentrations ranging between 527 and 367 ng L− 1, triazine compounds in the Hartbeespoort Dam catchmen

Seasonal variation of eight chloro-s-triazine herbicides and seven major atrazine and terbuthylazine degradation products was monitored in the Hartbeespoort Dam catchment using gas chromatography–mass spectrometry (GC–MS) and liquid chromatography-mass spectrometry (LC-MS/MS). Lake, river and groundwater were sampled from the Hartbeespoort Dam catchment over four seasons and the downstream Jukskei River was monitored during the winter season. Triazine herbicide concentrations in the Hartbeespoort Dam were in the order atrazine > simazine > propazine > ametryn > prometryn throughout the four seasons sampled. Triazine herbicide concentrations in the Hartbeespoort Dam surface water were highest in summer and gradually decreased in successive seasons of autumn, winter and spring. Terbuthylazine was the only triazine herbicide detected at all sampling sites in the Jukskei River, though atrazine recorded much higher concentrations for the N14 and Kyalami sites, with concentrations of 923 and 210 ng L− 1 respectively, compared to 134 and 74 ng L− 1 for terbuthylazine. Analytical results in conjunction with river flow data indicate that the Jukskei and Crocodile Rivers contribute the greatest triazine herbicide loads into the Hartbeespoort Dam. No triazine herbicides were detected in the fish muscle tested, showing that bioaccumulation of triazine herbicides is negligible. Atrazine and terbuthylazine metabolites were detected in the fish muscle with deethylatrazine (DEA) being detected in both catfish and carp muscle at low concentrations of 0.2 and 0.3 ng g− 1, respectively. Desethylterbuthylazine (DET) was detected only in catfish at a concentration of 0.3 ng g− 1. With atrazine herbicide groundwater concentrations being > 130 ng L− 1 for all seasons and groundwater ∑ triazine herbicide concentrations ranging between 527 and 367 ng L− 1, triazine compounds in the Hartbeespoort Dam catchmen

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 593 ng L−1 being recorded at the Midrand point and the lowest ∑11 EP concentration of 164 ng L−1 at the N14 site located 1 km 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 24 h 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 81 ng g−1 for nevirapine and 4 ng g−1 for etilefrine HCL. This study shows that efavirenz, nevirapine, carbamazepine, methocarbamol, bromacil and venlafaxine are contamin

A study of the distribution of polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs) utilising 16 priority PAHs, benzo(e) pyrene, perylene, 19 alkylated PAHs and 31 ortho substituted PCBs in South Africa is presented. It was aimed to (a) deduce characteristic contamination patterns for both PCBs and PAHs and (b) provide the first comprehensive dataset for establishment of source characterisation of PCBs and PAHs. This is in line with new South African legislation on mandatory monitoring of PCB and PAH emissions. Bar charts, principal component analysis (PCA) and biplots were utilised to identify signature contamination patterns and distribution of PCBs and PAHs within the Jukskei and Klip Rivers. Sediments from the Jukskei and Klip River catchments both showed distinct contamination signatures for hexa to nonachlorinated PCBs, characteristic of contamination by Aroclor 1254 and 1260 technical mixtures. PCB signature patterns in order of abundance were 138 > 180 > 206 > 153 > 187 > 149 and 138 > 153 > 180 > 149 > 187 > 110 > 170 for the Jukskei and Klip River sediments, respectively. The upstream Alberton point had the highest Sigma 31 PCB and Sigma (parent+alkyl) PAH concentrations in the Klip River of 61 and 6000 mu g kg(-1) dry weight (dw), respectively. In the Jukskei River, the upstream Marlboro point had the highest Sigma 31 PCB concentration of 19 mu g kg(-1) dw and the N14 site recorded the highest Sigma(parent+alkyl) PAH concentration of 2750 mu g kg(-1) dw. PAH concentrations in both the Jukskei and Klip Rivers were significantly higher than the PCB concentrations. Fluoranthene, phenanthrene and pyrene were found in the highest concentrations in both the Jukskei and Klip River sediments. Both the Jukskei and Klip River sediments showed trends of a mixed pyrogenic-petrogenic PAH source contamination.

The seasonal variability of persistent organic pollutants in Hartbeespoort Dam, South Africa, was investigated using semipermeable membrane devices (SPMDs) as passive samplers. Freely dissolved waterborne polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) were sampled to investigate seasonal changes in their concentrations. Exposure of the passive samplers was done for 14 days at the same sampling site in each of the four seasons of the year, in 2011. The SPMD-derived analyte amounts enabled the calculation of time-weighted averages of free dissolved waterborne levels of the contaminants. Concentrations ranged from 30.0 ng.l(-1) to 51.5 ng.l(-1) for PAHs, 38 pg l(-1) to 150 pg.l(-1) for PCBs, 9.2 to 10.4 ng.l(-1) for HCHs and 0.3 to 0.8 ng.l(-1) for DDTs, respectively. It was also noted that the winter season generally exhibited higher contaminant concentrations for most compounds studied, which likely reflects the seasonality of their atmospheric deposition. An attempt was also made to identify possible sources of PAH contaminants in the dam by examining PAH ratios. These diagnostic ratios were inclined towards pyrogenic sources of pollution, except for the winter season where both pyrogenic and petrogenic sources likely contribute to the contamination pattern., Funding Agencies:European Regional Development FundMinistry of Education of the Czech Republic LM2011028 LO1214Project "Employment of Best Young Scientists for International Cooperation Empowerment" CZ.1.07/2.3.00/30.0037European Social FundState budget of the Czech RepublicNational Research FoundationWater Research Commission of South Africa

In this study, the semipermeable membrane device (SPMD) passive samplers were used to determine freely dissolved concentrations of polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) in selected water bodies situated in and around Johannesburg City, South Africa. The devices were deployed for 14 days at each sampling site in spring and summer of 2011. Time weighted average (TWA) concentrations of the water-borne contaminants were calculated from the amounts of analytes accumulated in the passive samplers. In the area of interest, concentrations of analytes in water ranged from 33.5 to 126.8 ng l(-1) for PAHs, from 20.9 to 120.9 pg l(-1) for PCBs and from 0.2 to 36.9 ng l(-1) for OCPs. Chlorinated pesticides were mainly composed of hexachlorocyclohexanes (HCHs) (0.15-36.9 ng l(-1)) and dichlorodiphenyltrichloromethane (DDT) with its metabolites (0.03-0.55 ng l(-1)). By applying diagnostic ratios of certain PAHs, identification of possible sources of the contaminants in the various sampling sites was performed. These ratios were generally inclined towards pyrogenic sources of pollution by PAHs in all study sites except in the Centurion River (CR), Centurion Lake (CL) and Airport River (AUP) that indicated petrogenic origins. This study highlights further need to map up the temporal and spatial variations of these POPs using passive samplers., Funding Agencies:Czech Ministry of Education of the Czech Republic LM2011028 LO1214National Research Foundation (NRF)Water Research Commission (WRC) of South Africa

The potential of combination of liquid membranes (microporous membrane liquid-liquid extraction) and molecularly imprinted polymers (MIPs) was performed using 17 beta-estradiol (E2) as model compound. The model compound was extracted from aqueous sample through a hydrophobic porous membrane that was impregnated with hexane/ethyl acetate (3:2), which also formed part of the acceptor phase. In the acceptor phase, the compound was bound onto MIP particles that were also part of the organic phase. The potential of such combination was optimised for the type and amount of MIP particles in the organic acceptor phase, the extraction time, and the type of organic acceptor solvent. Ultrasound assisted binding of E2 onto MIP particles was also investigated. MIPs prepared by precipitation polymerization were found to be superior to those prepared by bulk polymerization. Increase in the extraction time and the amount of MIP particles in the acceptor phase led to more E2 binding onto the MIP particles. Hexane/ethyl acetate (3:2) as an organic acceptor was found to give higher E2 binding onto MIP particles compared to toluene, diethyl ether, and hexane. Ultrasound was furthermore found to increase the binding of E2 onto MIP particles. The selectivity of the technique was demonstrated by extracting wastewater and where clean chromatograms were obtained compared to liquid membrane extractions (SLMs) alone., QC 20100525

A selective extraction technique based on the combination of liquid membrane (microporous membrane liquid-liquid extraction) and molecularly imprinted polymers (MIP) was applied to triazines herbicides in food samples. Simazine, atrazine and propazine were extracted from aqueous food samples through the hydrophobic porous membrane that was impregnated with toluene, which also formed part of the acceptor phase. In the acceptor phase, the compounds were re-extracted onto MIP particles. The extraction technique was optimised for the amount of molecularly imprinted polymers particles in the organic acceptor phase, extraction time, and type of organic acceptor solvent and desorption solvent. An extraction time of 90 min and 50 mg of MIP were found to be optimum parameters. Toluene as the acceptor phase was found to give higher triazines binding onto MIP particles compared to hexane and combinations of diethyl ether and hexane. 90% methanol in water was found to be the best desorption solvent compared to acetonitrile, methanol and water. The selectivity of the technique was demonstrated by extracting spiked lettuce and apple extracts where clean chromatograms were obtained compared to liquid membrane extraction alone or to the microporous membrane liquid-liquid extraction - non-imprinted polymer combination. The MIP showed a certain degree of group specificity and the extraction efficiency in lettuce extract was 79% (0.72) for simazine. 98% (1.55) for atrazine and 86% (3.08) for propazine., QC 20100525