Browsing by Author "Henkelmann, Bernhard"

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    Comparative exposomics of persistent organic pollutants (PCBs, OCPs, MCCPs and SCCPs) and polycyclic aromatic hydrocarbons (PAHs) in Lake Victoria (Africa) and Three Gorges Reservoir (China)
    (Science of the Total Environment, 2019) Omwoma, Solomon; Muendo Mbithi, Bonface; Pandelova, Marchela; Ssebugere, Patrick; Lalah, Joseph O.; Wang, Yawei; Bi, Yonghong; Henkelmann, Bernhard; Schramm, Karl-Werner
    Exposomics is assessment of organism exposure to high priority environmental pollutants in an ecosystem using OMIC technologies. A virtual organism(VO) is an artificial property-tool (OMIC) reflecting exposomic process in compartments of real organisms. The exposomics of aquatic organisms inhabiting Lake Victoria (L.V.) and Three Gorges Reservoir (TGR) were compared using VOs. The two reservoirs are heavily depended on for food and water both in Africa and China. The target priority pollutants in the reservoirs were polyclic aromatic hydrocarbons (PAHs) and persistent organic pollutants such as polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs), medium chain chlorinated paraffins (MCCPs) and short chain chlorinated paraffins (SCCPs). The VOs showed that in a period of 28 days, aquatic organisms in TGR were exposed to total (Σ) PAHs of 8.71 × 10−6 mg/L, PCBs of 2.81 × 10−6 mg/L, OCPs of 2.80 × 10−6 mg/L, MCCPs of 8.9 × 10−10 mg/L and SCCPs of 1.13 × 10−7 mg/L. While in a period of 48 days, organisms in L. V. were exposed to total (Σ) PAHs of 7.45 × 10−6 mg/L, PCBs of 4.70 × 10−6 mg/L, OCPs of 3.39 × 10−8 mg/L,MCCPs of 4.6 × 10−10 mg/L and SCCPs of 3.6 × 10−9 mg/L. The exposomic levels in TGR after 28 dayswere higher than those in Lake Victoria after 48 days. In both reservoirs, bioaccumulation levels are above set standards for aquatic organisms. The sources of the pollutants into the reservoirswere diagnostically determined to originate fromanthropogenic processes such as petrogenic, diesel emissions, biomass burning, coal combustion, electronic wastes, traffic emissions and historic uses.
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    Multiple persistent organic pollutants in mothers' breastmilk: Implications for infant dietary exposure and maternal thyroid hormone homeostasis in Uganda, East Africa
    (Science of The Total Environmen, 2021) Matovu, Henry; Li, Zhong-Min; Henkelmann, Bernhard; Bernhöft, Silke; De Angelis, Meri; Schramm, Karl-Werner; Sillanpää, Mika; Drago Kato, Charles; Ssebugere, Patrick
    Persistent organic pollutants (POPs) are ubiquitous contaminants with adverse health effects in the ecosystem. One of such effects is endocrine disruption in humans and wildlife even at background exposure concentrations. This study assessed maternal breastmilk concentrations of POPs; brominated flame retardants (BFRs), polychlorinated biphenyls (PCBs) and polychlorinated dibenzo-p-dioxins/furans (PCDD/Fs), and the potential health risks posed to the nursing infants. We also evaluated the association of these POPs with total 3,3′,5- triiodo-L-thyronine (T3), L-thyroxine (T4), and 3,3′,5′-triiodo-L-thyronine (rT3) levelsmeasured in human breast milk. Thirty breastmilk samples were collected from Kampala, Uganda between August and December 2018. Hexabromobenzene was not detected while the maximum level of 2,2′,4,4′,5,5′-hexabrombiphenyl was 64.7 pg/g lw. The median levels of total indicator PCBs, PBDEs, dioxin-like PCBs, and PCDD/Fs in the samples were 159 pg/g lw, 511 pg/g lw, 1.16 pg TEQ/g lw, and 0.4 pg TEQ/g lw, respectively. These levels were lower than those reported in other countries. Owing to their bio accumulative nature, PCBs −81, −169, andΣPCDD/Fs increased with increase in maternal age. Estimated dietary intakes for dioxin-like PCBs and PCDD/Fs were lower than those reported elsewhere but were higher than the WHO tolerable daily intakes suggesting potential health risks to nursing infants. In adjusted single pollutant models, PCB-126, PCB-169, andΣPCBTEQ were negatively associated with T3, while 1,2,3,4,5,7,8-HpCDF was positively associated with rT3. Although these associations did not persist in multi pollutant models, our findings suggest potential thyroid hormone disruption by POPs in mothers. This may reduce the levels of thyroid hormones transferred from the mother to the neonates and, hence, adversely influence infant growth. A temporal study with a bigger sample size is required to corroborate these findings
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    PCDD/Fs and dioxin-like PCBs in fish species from Lake Victoria, East Africa
    (Chemosphere, 2013) Ssebugere, Patrick; Kiremire, Bernard T.; Henkelmann, Bernhard; Bernhöft, Silke; Kasozi, Gabriel N.; Wasswa, John; Schramm, Karl-Werner
    Two commercially important fish species, Nile perch (Lates niloticus) and Nile tilapia (Oreochromis niloticus) belonging to different trophic levels were collected from the Napoleon Gulf and Thurston Bay in Lake Victoria. Polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and dioxinlike polychlorinated biphenyls (dl-PCBs) were extracted from the fish muscles and livers using the 13C isotope dilution method, followed by multiple column chromatography clean-up. Analysis was achieved by a high resolution gas chromatography coupled with a high resolution mass spectrometer. The concentrations of analytes ranged from 0.07 to 0.59 pg g 1 fresh weight (fw) and 0.3–19.0 pg g 1 in L. niloticus and 0.06–0.18 and 0.2–15.7 pg g 1 in O. niloticus, for PPCDD/Fs and Pdl-PCBs, respectively. Differences in congener concentrations were observed between the two fish species and study sites, and this was attributed to differences in feeding habits and trophic levels. World Health Organization-toxic equivalents (WHO-TEQs) were in the range 0.01–0.16 pg TEQ g 1 for the PCDD/Fs and 0.001–0.74 pg TEQ g 1 for the dl-PCBs. The TEQ values in the present study were lower compared to those of most fish samples reported in literature and were within permissible levels recommended by the European Union, implying that the fish was fit for human consumption.
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    PCDD/Fs and dioxin-like PCBs in surface sediments from Lake Victoria, East Africa
    (Science of the total environment, 2013) Ssebugere, Patrick; Kiremire, Bernard T.; Henkelmann, Bernhard; Bernhöft, Silke; Wasswa, John; Kasozi, Gabriel N.; Schramm, Karl-Werner
    Surface sediments (b60 cm) from the Napoleon Gulf and Thurston Bay on the northern shore of Lake Victoria were analyzed for polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and dioxin-like polychlorinated biphenyls (dl-PCBs). Fifteen PCDD/Fs and eleven dl-PCBs were found in 75.5% of the samples. The maximum concentrations of PCDD/Fs and dl-PCBs were 44.1 and 136 pg g−1 dry weight (dw), respectively. Octachlorodibenzo-p-dioxin was the predominant PCDD/F congener at the Napoleon Gulf and Thurston Bay area. Regarding the dl-PCBs, a variation in levels was observed between the mono-ortho PCBs and non-ortho PCBs, with the former having higher levels than the latter. The PCDD/F and dl-PCB levels, in the sediments of Napoleon Gulf, which is near urban centers and industrial areas were markedly higher (α ≤ 0.05) than those from the Thurston Bay, which is offshore, suggesting that human activities could be sources of the pollutants to the surrounding water resources. World Health Organization-toxic equivalency quotients (WHO-TEQs) lay in the range of 0.07–5.53 pg g−1 dw for PCDD/Fs and 0.01–0.23 pg g−1 dw for dl-PCBs. 23.1% of samples from the Napoleon Gulf had their results above the set WHOPCDD/Fs-TEQ value.