Oestrogenic activity in drinking waters from a rural area in the Waterberg District, Limpopo Province, South Africa

In South Africa, limited data are available regarding possible oestrogenic activity in the aquatic systems and especially drinking water. Water in the rural areas is often contaminated with a complex mixture of toxic compounds originating from nearby industries, agriculture and households. In these rural areas the only access to drinking water is boreholes, natural springs and rivers. Thus human exposure to environmental contaminants in drinking water is potentially high. Two rural communities near Mokopane in the Waterberg district of the Limpopo Province were selected in order to screen for oestrogenic activity in drinking water sources in a rural area. Eleven 1 . water samples (Molekane n= 4; Sekuruwe n= 7), were collected in prepared glass bottles and extracted on a SPE C18 cartridge and reconstituted into ethanol. The recombinant yeast oestrogen screen was used to determine the oestrogenic activity in the extracts. 17ƒÀ-estradiol (E2) was used as a positive control and the results were expressed as estradiol equivalents (EEq). The EEq of the water from both the communities ranged between 0.63 - 2.48 x10-9 g/.. These concentrations are similar to other studies conducted in Korean river waters in rural and city areas and Flemish surface waters. The recombinant yeast screen confirmed oestrogenic activity in the drinking water samples; further investigation is necessary to determine the source of the contamination and association with impaired growth

The role of effect-based methods to address water quality monitoring in South Africa : a developing country’s struggle

Water is an important resource, and it is a worldwide struggle to provide water of good quality to the whole population. Despite good governing laws and guidelines set in place to help protect the water resources and ensure it is of good quality for various consumers, the water quality in South Africa is worsening due to lack of management. The deteriorating infrastructure is becoming progressively worse, due to corruption and insufficient funds. The ever-increasing number of toxicants, as well as the identification of emerging chemicals of concern, are also challenges South Africa is facing. Chemical analysis cannot determine the total biological effect of a mixture of chemical compounds, but this shortcoming can be addressed by adding effect-based methods (EBMs) to water quality monitoring programmes. In this paper, the current status of water quality monitoring in South Africa is discussed, as well as the capacity of the country to add EBMs to its water quality monitoring programmes to protect and improve human and animal life.The National Research Foundation and the Water Research Commission of South Africa.https://link.springer.com/journal/11356hj2023Urolog

Pesticide residues and estrogenic activity in fruit and vegetables sampled from major fresh produce markets in South Africa

Food is likely to be one of the major pathways through which people are exposed to endocrinedisrupting chemicals. With the exception of residual effects, there are concerns that a number of naturally occurring and synthetic chemicals exert adverse effects upon endocrine systems in wildlife and humans. The current study reports selected pesticide concentrations and the total estrogenic activity of fruit and vegetables using the recombinant yeast oestrogen screen (YES) and T47D-KBluc reporter gene assays. A total of 53 food samples (27 fruit and 26 vegetables) from Johannesburg and Tshwane fresh produce markets (in South Africa) were analysed. Of these, 17 contained one to three different pesticide residues with concentrations ranging between 0.01 and 0.68 mg kg–1, whereas in the rest of the samples no residues were detected. All pesticides detected except in one sample were below the maximum residue level (MRL), but others were unauthorised for use in specified fruit and vegetables. Estrogenic activity was detected in 26.4% (14 samples) of the samples tested, and the estradiol equivalents ranged from 0.007 to 2 pg g–1. Although the estrogenic activity was low, it may contribute to adverse health effects. Continuous monitoring for pesticides in fruit and vegetables is important in view of the unauthorised pesticides detected in produce from South Africa and the endocrine-disrupting chemical activity found.South African Table Grape Industry, the University of Pretoria, Institute of Food Nutrition and Well-Being, Department of Science and Technology and the National Research Foundation administered Centre of Excellence in Food Security (Project No 140701).http://www.tandfonline.com/loi/tfac202017-07-30hb201

Endocrine disrupting chemicals in commercially available cling film brands in South Africa

Cling films comprise of plasticizers which are known endocrine disrupting chemicals (EDCs). Cling films are commonly used for food packaging and EDCs may leach into food, increasing exposure, leading to adverse health outcomes. We determined the levels of common selected EDCs expected in commercial cling film brands sold in South Africa. We tested for para-nonylphenol (p-NP), bisphenol A (BPA), bis(2-ethylhexyl) adipate (DEHA), and phthalates [di-2-ethyhexyl phthalate (DEHP) and dibutylphthalate (DBP)]. We selected eight brands of cling film and used standard chromatography methods to extract compounds. We found p-NP in one brand (2.06 µg/kg) and BPA in two brands (1.48 and 1.61 µg/kg). Five brands contained DEHP (2.1–2.59 mg/kg), DBP (0.62–1.21 mg/kg) and DEHA (165.89–674.07 mg/kg). Levels of DEHA and DEHP in the cling film are associated with potential human health risks. The maximum level of DEHA ranged from 1.6 to 16 times the safe level, with a calculated hazard quotient of 1.4. The two cling film brands made from low density polyethylene (LDPE), both endorsed by the Cancer Association of South Africa (CANSA), had target chemicals below the detection limit.http://www.tandfonline.com/loi/bher202020-05-23hj2019School of Health Systems and Public Health (SHSPH)Urolog

Health risk implications from simultaneous exposure to multiple environmental contaminants

Water quality has deteriorated in the upper Olifants River system, South Africa, as a result of land use activities which include mining, agriculture and industries. A health risk assessment was conducted from 2009 to 2011 in the catchment to determine the possible risks local communities face from various pollutants such as microbials, heavy metals and oestrogen in the river water and vegetation. Aluminium and manganese accumulated in plants and vanadium and aluminium concentrations found in selective water samples posed significant health risks when consumed. A quantitative microbial risk assessment revealed that the combined risk of infection ranged from 1 to 26 percent with the Norovirus posing the overall greatest health risk. The anticipated disability adjusted life years resulting from drinking untreated water from these sites are in the order of 10,000 times greater than what is considered acceptable. The oestradiol activity, caused by endocrine disrupting compounds in the water, measured above the trigger value of 0.7 ng L−1. Impoverished communities in the area, who partially depend on river water for potable and domestic use, are exposed to immune-compromising metals that increase their probability of infection from waterborne diseases caused by the excess microbial pathogens in the contaminated surface water.Olifants River Forumhttp://www.elsevier.com/locate/ecoenvhb201

Estrogenic activity, chemical levels and health risk assessment of municipal distribution point water from Pretoria and Cape Town, South Africa

Endocrine disrupting chemicals (EDCs) are ubiquitous in the environment and have been detected in drinking water from various countries. Although various water treatment processes can remove EDCs, chemicals can also migrate from pipes that transport water and contaminate drinking water. This study investigated the estrogenic activity in drinking water from various distribution points in Pretoria (City of Tshwane) (n = 40) and Cape Town (n = 40), South Africa, using the recombinant yeast estrogen screen (YES) and the T47D-KBluc reporter gene assay. The samples were collected seasonally over four sampling periods. The samples were also analysed for bisphenol A (BPA), nonylphenol (NP), di(2-ethylhexyl) adipate (DEHA), dibutyl phthalate (DBP), di(2-ethylhexyl) phthalate (DEHP), diisononylphthalate (DINP), 17β-estradiol (E2), estrone (E1) and ethynylestradiol (EE2) using ultra-performance liquid chromatography-tandem mass spectrophotometry (UPLC-MS/MS). This was followed by a scenario based health risk assessment to assess the carcinogenic and toxic human health risks associated with the consumption of distribution point water. None of the water extracts from the distribution points were above the detection limit in the YES bioassay, but the EEq values ranged from 0.002 to 0.114 ng/L using the T47D-KBluc bioassay. BPA, DEHA, DBP, DEHP, DINP E1, E2, and EE2 were detected in distribution point water samples. NP was below the detection limit for all the samples. The estrogenic activity and levels of target chemicals were comparable to the levels found in other countries. Overall the health risk assessment revealed acceptable health and carcinogenic risks associated with the consumption of distribution point water.The South African Medical Research Councilhttp://www.elsevier.com/locate/chemosphere2018-11-30hj2017School of Health Systems and Public Health (SHSPH)Urolog

Alterations in male reproductive hormones in relation to environmental DDT exposure

DDT [1, 1, 1-trichloro-2,2-bis (p-chlorophenyl)-ethane] compounds are used for indoor residual spraying (IRS) to control malaria mosquitoes. DDT is an endocrine disruptor chemical in experimental conditions, but little is known of adverse effects related to living conditions with continual uptake across a time span by all possible means of exposure. Based on estrogenic and/or anti-androgenic effects found in animal studies, we hypothesized that chronic DDT/DDE exposures in men may be associated with changes in male reproductive hormones. We tested this hypothesis by compared the magnitude and direction of associations between DDT and DDE (1,1-dichloro-2,2-bis(p-chlorophenyl) ethylene) concentrations and male reproductive hormones in samples collected from IRS and non-IRS areas. We sampled a cross-section of 535 men (aged 18–40 years). Men living in IRS villages had significantly higher DDT and DDE concentrations compared with men from non-IRS villages. Men with DDT or DDE uptake (as reflected in detectable plasma concentrations) had significantly higher total-, free and bio-available testosterone (T), and lower follicle stimulating hormone (FSH) concentrations; lower luteinizing hormone (LH) concentrations were only evident with DDT uptake. To establish a dose-dependent effect, four sub-categories were defined. Men with the highest DDT (74–519 μg/g) and DDE (173–997 μg/g) concentrations had significantly higher total-, free and bio-available T, and lower FSH concentrations compared with subjects with non-detectable isomer concentrations. Estradiol concentrations were significantly higher in men with DDT and DDE concentrations in both the third (DDE: 27–172 μg/g; DDT: 5–73 μg/g) and fourth (DDE: 173–997 μg/g; DDT: 74–519 μg/g) categories. Men from IRS villages were significantly more likely to have higher total and bioavailable T as well as higher estradiol concentrations OR = 2.5 (95% CI 1.2, 3.2); OR 2.5 (95% CI 1.6, 4.0) and OR = 2.3 (95% CI 1.3, 4.1) compared to men from non-IRS villages, after controlling for age, BMI, personal use of pesticides, and smoking. Men living in IRS villages with life-long exposure (17.6 (±6) years) at the current residence with multiple exposure modalities incurred the highest degree of physiological imbalance over and above circulating isomer concentrations. Further studies are needed to elucidate the health implications of these findings.Grants from the MRC and NRF awarded to Prof Christiaan de Jager.http://www.elsevier.com/locate/envint2019-04-01hj2018Chemical PathologySchool of Health Systems and Public Health (SHSPH)Urolog

Changes in Retinol-Binding Protein Concentrations and Thyroid Homeostasis with Nonoccupational Exposure to DDT

BACKGROUND: The insecticide dichlorodiphenyltrichloroethane (DDT) has been used for malaria vector control in the northern and eastern parts of the Vhembe District of Limpopo Province, South Africa, since 1945. Bioaccumulation of DDT raises concern because it reportedly affects thyroid function. OBJECTIVE: Our objective was to investigate the association between DDT uptake (as reflected in plasma concentrations) and thyroid homeostasis while considering related factors. METHODS: We compared dietary intake, serum retinol-binding protein (RBP), transthyretin (TTR) and albumin concentrations, and liver and thyroid function between cases with evidence of a body burden of DDT in the circulation (concentration of any DDT isomer ≥ 0.02 μg/g lipid; n = 278) and controls (concentration of all DDT isomers < 0.02 μg/g lipid; n = 40) in a cross-sectional study. Further analyses were performed to assess the relevance of changes in RBP status associated with DDT uptake. RESULTS: RBP concentrations below the reference range were more prevalent in cases (54% vs. 10% in controls; χ2 = 27.4; p < 0.001), which could not be explained by nutrient intake. We observed significantly lower thyroid hormone concentrations among cases (p ≤ 0.01). We also observed a significant linear trend for serum concentrations of free thyroxine and free triiodothyronine (p < 0.001) and a significant quadratic trend for serum thyroid-stimulating hormone (p = 0.025) and TTR (p < 0.001) across the control group and case groups with normal and relatively low RBP concentrations. Relatively low RBP concentrations were associated with significantly higher DDT and 1,1-dichloro-2,2-bis(p-chlorophenyl) ethylene (DDE) isomer concentrations and with a higher DDE/DDT ratio (p ≤ 0.01), which signifies long-term exposure. Inadequate intake of vitamin A and zinc were observed in 84% and 58%, respectively, of the total study population. CONCLUSION: RBP concentrations appear to decrease in the presence of long-term DDT uptake, which may have deleterious effects on thyroid function and vitamin A nutritional status. This is of major concern in a population with poor vitamin A and zinc intake