Comprehensive two-dimensional gas chromatography coupled to high resolution time-of-flight mass spectrometry for screening of organohalogenated compounds in cat hair

The coupling of comprehensive two-dimensional gas chromatography with high-resolution time-of-flight mass spectrometry offers the best separation efficiency combined with accurate mass measurements over a wide mass range. The tremendous power of this screening tool is illustrated by trace qualitative screening analysis of organohalogenated compounds (OHCs) in pet cat hair. Tentative identification was supported by mass spectral database searches and elemental formula prediction from the experimentally determined accurate mass data. This screening approach resulted in the first tentative identification of pentabromoethylbenzene, decabromodiphenyl ethane, hexabromocyclododecane, trisbromoneopentyl alcohol, tris(2-chloroethyl) phosphate and tris(2-chloroisopropyl)phosphate in the South African indoor environment. A total of seventy-two OHCs were identified in the samples and include known flame retardants, such as polybrominated diphenyl ethers, and legacy contaminants such as polychlorinated biphenyls and organochlorine, organophosphorous and pyrethroid pesticides. The results obtained from cat hair indicate that these pets are exposed to complex mixtures of OHCs and the detection of these compounds suggests that non-invasive cat hair samples can be used to model indoor exposure with reference to external deposition of OHCs present in the air and dust surrounding people. Toddlers share the same environment as pet cats and therefore also the same health risks

Position paper on undergraduate palliative medicine education for doctors in South Africa

BACKGROUND : Basic palliative care teaching should be included in training curricula for health care providers (HCPs) at all levels of the health service to ensure that the goal set by the South African (SA) National Policy Framework and Strategy for Palliative Care, to have an adequate number of appropriately trained HCPs in South Africa, is achieved. Furthermore, palliative learning objectives for nurses and doctors should be standardised. Many SA medical schools have integrated elements of Palliative Medicine (PM) teaching into undergraduate medical training programmes for doctors; however, the degree of integration varies widely, and consensus and standardisation of the content, structure and delivery of such PM training programmes are not yet a reality AIM : This joint position paper aims to describe the current state of undergraduate medical PM teaching in South Africa and define the PM competencies required for an SA generalist doctor SETTING : Palliative Medicine programme leads and teachers from eight medical schools in South Africa METHODS : A survey exploring the structure, organisation and content of the respective medical undergraduate PM programmes was distributed to PM programme leads and teachers RESULTS : Responses were received from seven medical schools. Through a process of iterative review, competencies were defined and further grouped according to suitability for the pre-clinical and clinical components of the curriculum CONCLUSION : Through mapping out these competencies in a spiralled medical curriculum, the authors hope to provide guidance to medical curriculum designers to effectively integrate PM teaching and learning into current curricula in line with the goals of the SA National Policy Framework and Strategy on Palliative Care (NPFSPC).http://www.phcfm.orgam2023Family Medicin

Species identification of adult African blowflies (Diptera: Calliphoridae) of forensic importance:

Necrophagous blowflies can provide an excellent source of evidence for forensic entomologists and are also relevant to problems in public health, medicine, and animal health. However, access to useful information about these blowflies is constrained by the need to correctly identify the flies, and the poor availability of reliable, accessible identification tools is a serious obstacle to the development of forensic entomology in the majority of African countries. In response to this need, a high-quality key to the adults of all species of forensically relevant blowflies of Africa has been prepared, drawing on high-quality entomological materials and modern focus-stacking photomicroscopy. This new key can be easily applied by investigators inexperienced in the taxonomy of blowflies and is made available through a highly accessible online platform. Problematic diagnostic characters used in previous keys are discussed

Diversity of bacteria isolated from the flies Musca domestica (Muscidae) and Chrysomya megacephala (Calliphoridae) with emphasis on vectored pathogens.

We evaluated the bacteria occurring externally on Musca domestica and Chrysomya megacephala, the two most common synanthropic flies which may be found at many refusesites throughout the world. Bacteria cultured from 10 specimens of each species were isolated, Gram-stained and examined microscopically, and divided into morphologically distinct 'pseudospecies', to avoid excessive duplication of genetic identification. About 350 bp of the 16S ribosomalRNAgene was amplified from genomic DNA extracted from each 'pseudospecies', sequenced, and bacteria identified using BLASTn. Nineteen different types of colony were identified from M. domestica, with Pseudomonas sp. and Swine Manure Bacterium SP14 being most abundant. Chrysomya megacephala yielded 15 distinct pseudospecies with total colony counts approximating to 10 000 from 10 plates, where 80% of colonies were non-pathogenic Bacillus pumilus. A total of 18 species were identified genetically: three shared by the fly species; four unique to C. megacephala,, and 13 unique to M. domestica. Half of these 18 species were pathogenic, two or three others were food spoilers and the rest were environmental or commensal bacteria from soil or plant matter. This study added three new pathogenic strains of bacteria and one new environmental strain to the list of bacteria reported to be vectored by these flies

Diversity of bacteria isolated from the flies Musca domestica (Muscidae) andChrysomya megacephala (Calliphoridae) with emphasis on vectored pathogens

Publisher versionWe evaluated the bacteria occurring externally on Musca domestica and Chrysomya megacephala, the two most common synanthropic flies which may be found at many refuse sites throughout the world. Bacteria cultured from 10 specimens of each species were isolated, Gram-stained and examined microscopically, and divided into morphologically distinct ‘pseudospecies', to avoid excessive duplication of genetic identification. About 350 bp of the 16S ribosomalRNAgene was amplified from genomicDNAextracted from each ‘pseudospecies', sequenced, and bacteria identified using BLASTn. Nineteen different types of colony were identified from M. domestica, with Pseudomonas sp. and Swine Manure Bacterium SP14 being most abundant. Chrysomya megacephala yielded 15 distinct pseudospecies with total colony counts approximating to 10 000 from 10 plates, where 80 % of colonies were non-pathogenic Bacillus pumilus. A total of 18 species were identified genetically: three shared by the fly species; four unique to C. megacephala, and 13 unique to M. domestica. Half of these 18 species were pathogenic, two or three others were food spoilers and the rest were environmental or commensal bacteria from soil or plant matter. This study added three new pathogenic strains of bacteria and one new environmental strain to the list of bacteria reported to be vectored by these flies

Chlorinated paraffins and tris (1-chloro-2-propyl) phosphate in spray polyurethane foams – A source for indoor exposure?

In this study, we investigated chemical additives present in new and used spray polyurethane foams (SPFs) and assessed the dermal transfer through direct contact. This first study shows that cured do-it-yourself spray one-component SPFs (OCFs) often contain chlorinated paraffins (C14-C37), and tris (1-chloro-2-propyl) phosphate (TCIPP), ranging 0.2–50%, and 0.9–30% w/w, respectively. Six OCFs contained CP levels ranging 22–50% w/w, whereas nine OCFs used for similar applications only contained CP levels ranging 2–17% w/w. It is unclear if the combination CPs/TCIPP is meant to improve the flame retardancy of products, and could suggest an unnecessary use of high CPs/TCIPP concentrations in OCFs. The two-component SPFs (TCFs) contained only TCIPP with levels ranging from 7.0% to 9.0%. The CPs and TCIPP were easily transferred from cured OCFs to the hands. Levels up to 590 µg per hand for CPs and up to 2.7 µg per hand for TCIPP were found. After end-of-life, it is challenging to recycle used SPFs. They may, therefore, end up at landfills where the TCIPP/CPs may leach into the environment. Therefore, further investigation is needed to assess potential exposure risks associated with general and occupational use, and the impact of landfill leaching on the environment

From rivers to the tap: Investigation of micro and nanoplastics in drinking water by pyrolysis-GC-MS

The occurrence of micro-and nanoplastics (MNPs) in freshwater has been globally recognized. This raised the question of possible human exposure to MNPs through drinking water from freshwater sources. Recent studies have shown that potable water may contain MNPs, but a high degree of variation in concentrations has been reported. These variations are attributed to the differences between raw water and the treatment and distribution processes. However, the analytical techniques employed for the identification and quantification of MNPs also have a significant role at the level of reported. To be able to estimate the MNP associated risks via drinking water consumption, reliable exposure concentrations with lower size limits of polymers are urgently needed. In the present study, a sensitive method was developed to detect and quantify MNPs in water samples based on the protein corona mediated aggregation of particles followed by filtration and analysis with pyrolysis-gas chromatograph-mass spectrometry (Py-GC-MS). The method was validated using different types of water and acceptable recoveries were obtained for PE, PP, PVC and PS ranging from 97 to 118%. Given the ubiquity of microplastics in freshwater systems and increased particle numbers with decreasing polymer sizes, this method is a promising tool to quantify MNPs in water samples and to evaluate the risks for human health

Critical review of the analysis of brominated flame retardants and their environmental levels in Africa

World-wide, the prevalence of brominated flame retardants (BFRs) is well documented for routine analysis of environmental and biological matrices. There is, however, limited information on these compounds in the African environment and insufficient information on the analytical approaches used to obtain data. This paper presents a review on BFR levels in the African environment and the various analytical methodologies specifically applied in Africa for polybrominated diphenyl ethers (PBDEs), polybrominated biphenyls and alternative-BFRs. The analyses include liquid sample preparation using liquid-liquid and solid phase extraction and solid sample preparation involving Soxhlet extraction, with ultrasound-assisted extraction increasingly being applied. Instrumental detection techniques were limited to gas chromatography coupled with electron capture detector and electron impact ionisation with single quadrupole mass spectrometers. Information on congener profile prevalence in indoor dust, soil, aquatic environment (water, sediment, and aquatic organisms), eggs, wastewater treatment plant compartments, landfills (leachate and sediment) and breast milk are presented. Although PBDEs were inconsistently detected, contamination was reported for all investigated matrices in the African environment. The manifestation in remote regions indicates the ubiquitous prevalence and long-range transport of these compounds. Levels in sediment, and breast milk from some African countries were higher than reported for Asia and Europe. Due to limited data or non-detection of alternative-BFRs, it is unclear whether banned formulations were replaced in Africa. Most of the data reported for BFR levels in Africa were obtained in non-African laboratories or in South Africa and formed the basis for our discussion of reported contamination levels and related methodologies.In part by the National Research Foundation of South Africa (VU University Amsterdam – NRF Desmond Tutu doctoral scholarship) (Grant number 94075).http://www.elsevier.com/locate/chemospherehj2019Chemistr

Short-, medium-, and long-chain chlorinated paraffins in South African indoor dust and cat hair

Polychlorinated n-alkanes or chlorinated paraffins (CPs) contain a magnitude of structural isomers and are categorized as short-chain (SCCPs), medium-chain (MCCPs), and long-chain (LCCPs) CPs, according to the carbon chain lengths. In this study the ƩSCCPs, ƩMCCPs, and ƩLCCP concentrations are reported for South African indoor dust and pet cat hair. The median concentrations of the ƩCPs (C9-C37) ranged from 33 to 663 μg/g for freshly collected dust (FD), 36-488 μg/g for dust collected from household vacuum cleaner bags (VD), and 1.2-15 μg/g for cat hair (CH) samples. MCCPs were the dominant CP group, followed by SCCPs and LCCPs. The ƩMCCP concentration ranged from 13 to 498 μg/g in dust and 0.6-6.5 μg/g in cat hair. SCCPs with shorter carbon chains and lower chlorine substitution were observed in cat hair. LCCPs with carbon chains > C20 were detected in dust and hair samples, possibly indicating the use of wax grade LCCP formulations. Non-traditional Kendrick mass defect plots were used to obtain information on the magnitude of CPs and provide evidence of possible interfering compounds. This is the first report on the occurrence of SCCPs, MCCPs, and LCCPs in the South African indoor environment