scholarly journals Exposure to DDT and HCH congeners and associated potential health risks through khat (Catha edulis) consumption among adults in South Wollo, Ethiopia

Author(s):  
Desta Woldetsadik ◽  
Marcel Pierre Simon ◽  
Dennis Knuth ◽  
Hillette Hailu ◽  
Araya Gebresilassie ◽  
...  

AbstractKhat (Catha edulis) chewing is widespread in the region of East Africa. Even low levels of organochlorine pesticides (OCPs) in khat could induce public health concern. In a market-based study, from five popular khat varieties, a total of 35 composite khat samples were analyzed for dichlorodiphenyltrichloroethane (DDT) and its main transformation products, and four hexachlorocyclohexane (HCH) isomers. Extraction was carried out by quick, easy, cheap, effective, rugged and safe method (QuEChERS). OCP concentrations were determined by head space solid phase microextraction coupled to gas chromatography-mass spectrometry (HS-SPME–GC–MS). Every sample contained β-HCH above the maximum residue limit set by the European Commission. For total DDT, this was the case for 25.7% of the samples. The ratios of (p,p′-DDD + p,p′-DDE) to p,p′-DDT were less than one for 85% of khat samples, demonstrating recent use of DDT in khat farmlands. Conversely, the ratio of β-HCH to total HCH varied from 0.56 to 0.96, implying historical input of technical HCH. Assuming a daily chewable portion of 100 g, dietary intakes of p,p′-DDT, total DDT and total HCH by adults ranged from 3.12 to 57.9, 6.49 to 80.2 and 39.2 to 51.9 ng (kg body weight)−1 day−1, respectively. These levels are below acceptable levels suggested by international organizations. Chewing khat showed lower non-cancer health risk, but showed relatively higher cancer risk in terms of OCPs. Because khat is chewed without being subjected to any treatment, uncertainties associated with estimated intakes and health risks should be low. Therefore, this practice is of great concern.

2018 ◽  
Vol 16 (2) ◽  
pp. 253-262 ◽  
Author(s):  
Natalie H. Aneck-Hahn ◽  
Magdalena C. Van Zijl ◽  
Pieter Swart ◽  
Barry Truebody ◽  
Bettina Genthe ◽  
...  

Abstract 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.


2021 ◽  
Author(s):  
Aray Zhakupbekova ◽  
Nassiba Baimatova ◽  
Elefteria Psillakis ◽  
Bulat Kenessov

Abstract Quantification of unsymmetrical dimethylhydrazine (UDMH) transformation products (TPs) in solid samples is an important stage in monitoring of environmental pollution caused by heavy rockets launches. The new method for simultaneous quantification of UDMH TPs in sand samples using vacuum-assisted headspace solid-phase microextraction (Vac-HSSPME) followed by gas chromatography-mass spectrometry (GC-MS) is proposed. Compared to regular HSSPME, Vac-HSSPME yielded 1.3–4.8 times higher responses for NDMA, MTA and PAl. Increasing air-evacuation time from 20 to 120 s at 23 ºC resulted in decreased responses of analytes by 25–46%. Freezing of samples (-30 ºC) had negligible effect on responses of analytes at air-evacuation time 20 s. The best combination of responses of analytes and their RSDs was achieved after air-evacuation of a sample (m = 1.00 g) for 20 s at 23 ºC, incubation for 30 min and 30-min extraction at 40°C by Car/PDMS fiber. Vac-HSSPME provided linear calibration plots in studied ranges of concentrations with coefficients of determination ranging from 0.9912 to 0.9938. The limits of detection for spiked sand samples varied from 0.035 to 3.6 ng g− 1. Spike recoveries of target analytes from sand samples were 84–97% with RSDs 1–11%. The developed method was successfully tested in the experiment on studying losses of analytes from open vials with model sand spiked with UDMH TPs. The developed method can be recommended for analysis of trace concentrations of UDMH TPs when studying their transformation, migration and distribution in contaminated sand.


2018 ◽  
Vol 115 (10) ◽  
pp. 2311-2316 ◽  
Author(s):  
Carsten Prasse ◽  
Breanna Ford ◽  
Daniel K. Nomura ◽  
David L. Sedlak

Water treatment systems frequently use strong oxidants or UV light to degrade chemicals that pose human health risks. Unfortunately, these treatments can result in the unintended transformation of organic contaminants into toxic products. We report an unexpected reaction through which exposure of phenolic compounds to hydroxyl radicals (•OH) or UV light results in the formation of toxic α,β-unsaturated enedials and oxoenals. We show that these transformation products damage proteins by reacting with lysine and cysteine moieties. We demonstrate that phenolic compounds react with •OH produced by the increasingly popular UV/hydrogen peroxide (H2O2) water treatment process or UV light to form toxic enedials and oxoenals. In addition to raising concerns about potential health risks of oxidative water treatment, our findings suggest the potential for formation of these toxic compounds in sunlit surface waters, atmospheric water, and living cells. For the latter, our findings may be particularly relevant to efforts to understand cellular damage caused by in vivo production of reactive oxygen species. In particular, we demonstrate that exposure of the amino acid tyrosine to •OH yields an electrophilic enedial product that undergoes cross-linking reaction with both lysine and cysteine residues.


Author(s):  
Obasi UCHE Orji ◽  
Udu Ama Ibiam ◽  
Nonso Joshua Awoke ◽  
Otuomasirichi Divine Obasi ◽  
Anayo Joseph Uraku ◽  
...  

Mining is one of the major sources of heavy metals in most developing countries and this has become a major health concern to the populace due to the possibility of food contamination with these heavy metals. We investigated the levels of titanium (Ti), manganese (Mn), nickel (Ni), copper (Cu), zinc (Zn), lead (Pb), rubidium (Rb), strontium (Sr), selenium (Se), niobium (Nb) and vanadium (V) in 64 soil and  320 samples of regularly consumed staple food crops and vegetables (cassava tubers, white yam, groundnut seed, fluted pumpkin leaf and Z. zanthoxyloides from farms around Enyigba mining sites in Ebonyi State and the possible health risks due to consumption of these staple foods. Energy dispersive X-ray fluorescence (EDXRF) was used in determination of the metals in the samples respectively. The mean levels of the metals except Mn, Pb and Zn were below the threshold limits for agricultural soils. Our data also showed that food crops cultivated around this sites bio-accumulated toxic levels of these metals above the recommended legal limits set by WHO, NAFDAC and CODEX especially Pb, Zn, Cu, Ni, Se, and Rb. This perhaps may have potential health implication on the local dwellers. The estimated daily intakes (EDI) of the toxic metals through the consumption of the crop samples were below the maximum tolerable daily intake (MTDI) except lead and nickel by eating of groundnut, cassava and yam. Furthermore, the target hazard quotient (THQ), computed based on EDI of the heavy metals were above unity for the metals due to cassava, yam and groundnut consumption, suggesting significant health risk. Raised amounts of heavy metal in cassava and groundnut samples as revealed by their metal extraction coefficient computed in this study hint that they may be used as bio-indicators of ecological, health hazards and phytoremediators of Mn, Zn, Cu, and Pb.


Author(s):  
Marta Oliveira ◽  
Cristina Delerue-Matos ◽  
Maria Carmo Pereira ◽  
Simone Morais

This work characterizes the dimension and the exceptionality of 2017 large- and mega-fires that occurred in the center region of Portugal through the assessment of their impact on the ambient levels of particulate matter (PM10 and PM2.5), retrieved from local monitoring stations, and the associated public health risks. PM10 and PM2.5 concentrations were increased during the occurrence of large fires and megafires, with daily concentrations exceeding the European/national guidelines in 7–14 and 1–12 days of 2017 (up to 704 µg/m3 for PM10 and 46 µg/m3 for PM2.5), respectively. PM10 concentrations were correlated with total burned area (0.500 < r < 0.949; p > 0.05) and with monthly total burned area/distance2 (0.500 < r < 0.667; p > 0.05). The forest fires of 2017 took the life of 112 citizens. A total of 474 cases of hospital admissions due to cardiovascular diseases and 3524 cases of asthma incidence symptoms per 100,000 individuals at risk were assessed due to exposure to 2017 forest fires. Real-time and in situ PM methodologies should be combined with protection action plans to reduce public health risks. Portuguese rural stations should monitor other health-relevant pollutants (e.g., carbon monoxide and volatile organic compounds) released from wildfires to allow performing more robust and comprehensive measurements that will allow a better assessment of the potential health risks for the exposed populations.


Molecules ◽  
2020 ◽  
Vol 25 (24) ◽  
pp. 6027
Author(s):  
Heting Qi ◽  
Shenghua Ding ◽  
Zhaoping Pan ◽  
Xiang Li ◽  
Fuhua Fu

Citrus tea is an emerging tea drink produced from tea and the pericarp of citrus, which consumers have increasingly favored due to its potential health effects and unique flavor. This study aimed to simultaneously combine the characteristic volatile fingerprints with the odor activity values (OAVs) of different citrus teas for the first time by headspace gas chromatography-ion mobility spectrometry (HS-GC-IMS) and headspace solid-phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS). Results showed that the establishment of a citrus tea flavor fingerprint based on HS-GC-IMS data can provide an effective means for the rapid identification and traceability of different citrus varieties. Moreover, 68 volatile compounds (OAV > 1) were identified by HS-SPME-GC-MS, which reflected the contribution of aroma compounds to the characteristic flavor of samples. Amongst them, the contribution of linalool with sweet flower fragrance was the highest. Odorants such as decanal, β-lonone, β-ionone, β-myrcene and D-limonene also contributed significantly to all samples. According to principal component analysis, the samples from different citrus teas were significantly separated. Visualization analysis based on Pearson correlation coefficients suggested that the correlation between key compounds was clarified. A comprehensive evaluation of the aroma of citrus tea will guide citrus tea flavor quality control and mass production.


Author(s):  
Dina Orazbayeva ◽  
Bulat Kenessov ◽  
Aray Zhakupbekova

Quantification of transformation products of unsymmetrical dimethylhydrazine (UDMH) in soil requires tedious, time- and labor-consuming sample preparation. The simple and fast method for quantification of transformation products of UDMH in aqueous extracts from soil using vacuum-assisted headspace solid-phase microextraction (Vac-HSSPME) was optimized in this work. The method is based on extraction of analytes from soil with water followed by Vac-HSSPME of the obtained aqueous extracts, and gas chromatography-mass spectrometry analysis. The target transformation products were: pyrazine, 1-methyl-1H-pyrazole, N-nitrosodimethylamine, N,N-dimethylformamide, 1-methyl-1Н-1,2,4-triazole, 1-methyl-imidazole and 1H-pyrazole. The effect of a sample pH on responses of target analytes was studied. It was negligible, and no pH adjustment was recommended before a subsequent extraction. The water amount was optimized to provide the best combination of analytes responses and their precision. Extraction by adding 7.00 mL of water to 2.0 g of soil ensured linear dependence of responses of the analytes on their concentrations in soil. The optimized method provided detection limits of target analytes in soil in the range from 0.2 to 9 ng/g. The spike recoveries obtained for model samples were in the range 90-103%. The developed method can be recommended for application in laboratories conducting routine analyses of soil samples potentially contaminated by rocket fuel residuals.


2019 ◽  
Vol 56 (4) ◽  
pp. 1165-1169 ◽  
Author(s):  
Jayne K Hanford ◽  
Dieter F Hochuli ◽  
Cameron E Webb

Abstract Constructed wetlands are popular tools for managing threatened flora and fauna in urban settings, but there are concerns that these habitats may increase mosquito populations and mosquito-related public health risks. Understanding the interactions occurring between mosquitoes of public health concern and co-occurring organisms is critical to informing management of these habitats to mitigate potential health risks and balance the multiple values of urban wetlands. This study examined how oviposition behavior of Culex annulirostris Skuse, the most important pest mosquito species associated with freshwater wetland habitats in Australia, is influenced by the presence of Gambusia holbrooki Girard, a widespread invasive fish. Water was collected from urban wetlands that are intensively managed to reduce G. holbrooki populations to assist conservation of locally threatened frogs, and adjacent unmanaged wetlands where G. holbrooki was abundant. Laboratory experiments were conducted to examine the oviposition response by Cx. annulirostris to water samples from these two habitats. Experiments were conducted on two occasions, once in February following draining and refilling of the urban wetlands, and repeated following a substantial rainfall event in March. The results clearly demonstrate that ovipositing mosquitoes were able to detect and avoid water derived from habitats containing fish, even in the absence of the fish themselves. Understanding how invasive species affect the behavior and spatial distribution of pest species such as Cx. annulirostris will enable future wetland design and management to maximize benefits of urban wetlands and minimize potential public health risks.


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