89 research outputs found

    Oestrogenicity and chemical target analysis of water from small-sized industries in Pretoria, South Africa

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    Increasing concern about endocrine disrupting chemicals (EDCs) and their effects on humans, animals and the environment resulted in this study being conducted. Water from 7 sites in the Pretoria West area (South Africa), with significant numbers of small-sized industries, was screened for oestrogenicity, using the Recombinant Yeast Cell Bioassay (RCBA). Target chemical analyses were carried out to establish the presence of EDCs, including p-nonylphenol (p-NP), bisphenol A (BPA), phthalate esters, polychlorinated biphenyls (PCBs) and various organochlorine pesticides, including dichlorodiphenyltrichloroethane (DDT). p-NP, PCBs and organochlorine pesticides were detected using LECO Pegasus II MSTOF and BPA and phthalates were detected using the GC-MS method. Oestrogenic activity was detected in all the samples collected from these sites. Lindane, an organochlorine pesticide, was detected at one site. p-NP, PCBs and phthalate esters were detected at some of the other sites. Small-size industries were found to contribute to EDC pollution of water in the Pretoria West area.Keywords: oestrogenicity, endocrine disrupting chemicals (EDCs), p-nonylphenol (p-NP), polychlorinated biphenyls (PCBs), bisphenol A (BPA), phthalate esters, organochlorine pesticides, dichlorodiphenyltrichloroethane (DDT), lindan

    The interpretation of a semen analysis : semen analysis is still a cornerstone laboratory evaluation

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    Male factor infertility is solely responsible in ∼20% of cases and contributory in ∼30 - 40%. Therefore, in at least 50% of cases a male factor for infertility contributes to failure to conceive. A semen analysis is still a cornerstone laboratory evaluation and contributes to defining the severity of a possible single or contributing male factor to a couple's infertility.http://www.cmej.org.za/index.php/cme

    Health risk implications from simultaneous exposure to multiple environmental contaminants

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    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

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    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

    Estrogenic activity, selected plasticizers and potential health risks associated with bottled water in South Africa

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    Potential endocrine disrupting chemicals (EDCs) are present in bottled water from various countries. In South Africa (SA), increased bottled water consumption and concomitant increases in plastic packaging create important consequences for public health. This study aimed to screen SA bottled water for estrogenic activity, selected target chemicals and assessing potential health risks. Ten bottled water brands were exposed to 20 °C and 40 °C over 10 days. Estrogenic activity was assessed using the recombinant yeast estrogen screen (YES) and the T47D-KBluc reporter gene assay. Solid phase extracts of samples were analyzed for bis(2-ethylhexyl) adipate (DEHA), selected phthalates, bisphenol-A (BPA), 4-nonylphenol (4-NP), 17β-estradiol (E2), estrone (E1), and ethynylestradiol (EE2) using gas chromatography–mass spectrophotometry. Using a scenario-based health risk assessment, human health risks associated with bottled water consumption were evaluated. Estrogenic activity was detected at 20 °C (n = 2) and at 40 °C (n = 8). Estradiol equivalent (EEq) values ranged from 0.001 to 0.003 ng/L. BPA concentrations ranged from 0.9 ng/L to 10.06 ng/L. Although EEqs and BPA concentrations were higher in bottled water stored at 40 °C compared to 20 °C, samples posed an acceptable risk for a lifetime of exposure. Irrespective of temperature, bottled water from SA contained chemicals with acceptable health risks.The Cancer Association of South Africa (CANSA).http://jwh.iwaponline.comhj2019School of Health Systems and Public Health (SHSPH

    Alterations in male reproductive hormones in relation to environmental DDT exposure

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    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

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    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
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