Chlorinated Paraffins in Car Tires Recycled to Rubber Granulates and Playground Tiles.

Chlorinated paraffins (CPs) are used in various products to improve their physicochemical characteristics. Due to recycling, CPs may end up in "new" recycled products. In this study we investigated CPs present in end-of-life car tires that are recycled to rubber granulates used on artificial soccer fields, and playground tiles. The ∑CP(C10-C30) concentrations ranged from 1.5 to 67 µg/g in car tires, 13-67 µg/g in rubber granulates, and 16-74 µg/g in playground tiles. MCCPs were the dominant CP group with an average contribution of 72%. LCCPs up to C30, were detected for the first time in car tires, rubber granulates, and playground tiles. The CPs application in tires is unclear, the low CP concentrations found in this study (<0.007%) could possibly indicate contamination during the manufacturing process. The presence of CPs in the granulates and tiles, in addition to the multiple chemicals already detected, emphasizes the need to further investigate the migration and leaching behavior, in order to assess potential risks of CPs for humans and the environment. The presence of CPs in car tires may be another source of CPs for the environment. The CP volume brought into the environment by tire wear particles (TWP) from car tires in the European Union, is estimated at 2.0-89 tons annually.

High concentration aqueous sodium fluoride certified reference materials for forensic use certified by complexometric titration.

Sodium fluoride in concentrations of 1 to 2 % is used to prevent the formation of ethanol in blood and urine samples that are to be analysed for ethanol content. The majority of such samples form part of forensic investigations into alleged drunken driving. In South Africa, the laboratory performing the tests is required to prove that the sodium fluoride concentration in the blood samples is above 1 g/100 ml on receipt. This is done by using a fluoride ion-selective electrode calibrated with external aqueous solutions of sodium fluoride. The National Metrology Institute of South Africa (NMISA) prepares sodium fluoride solutions in concentrations from 0.3 to 3.0 g/100 ml. No other certified sodium fluoride reference solutions in these concentrations are available commercially. The sodium fluoride is certified by precipitation of the fluoride as lead chlorofluoride (PbClF) through the addition of a known excess of lead nitrate. The excess lead is back-titrated with ethylenediamine tetraacetic acid (EDTA) using a photometric electrode to detect the endpoint. Aqueous sodium fluoride solutions are prepared and the concentrations verified by the precipitation/back-titration method. This paper shows the application of a classical complexometric method to the certification of reference materials and describes the procedures for the preparation of the sodium fluoride solutions, verification of the concentrations, homogeneity and stability by primary titrimetry. It also briefly covers the calculation of uncertainty, the establishment of traceability and the quality control measures applied to ensure the quality of the certified reference materials (CRMs).

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.

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 Æ©SCCPs, Æ©MCCPs, and Æ©LCCP concentrations are reported for South African indoor dust and pet cat hair. The median concentrations of the Æ©CPs (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 Æ©MCCP 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.

Brominated and organophosphorus flame retardants in South African indoor dust and cat hair.

Flame retardants (FRs), such as brominated flame retardants (BFRs) and organophosphorus flame retardants (OPFRs), are diverse groups of compounds used in various products related to the indoor environment. In this study concentrations of eight polybrominated diphenyl ethers (PBDEs), two alternative BFRs and ten OPFRs were determined in indoor dust (n = 20) and pet cat hair (n = 11) from South Africa. The OPFRs were the major FRs, contributing to more than 97% of the total FR concentration. The median Ʃ10OPFRs concentrations were 44,800 ng/g in freshly collected dust (F-dust), 19,800 ng/g in the dust collected from vacuum cleaner bags (V-dust), and 865 ng/g in cat hair (C-hair). Tris(1-chloro-2-propyl) phosphate (TCIPP) was the dominant OPFR in the dust samples with median concentrations of 7,010 ng/g in F-dust and 3,590 ng/g in V-dust. Tris(2-butoxyethyl) phosphate (TBOEP) was the dominant OPFR in C-hair, with a median concentration of 387 ng/g. The concentrations of Ʃ8PBDEs were higher in F-dust than in V-dust. BDE209 was the dominant BFR in all three matrices. Bis(2-ethylhexyl)-3,4,5,6-tetrabromo-phthalate (BEH-TEBP) and 2-ethylhexyl-2,3,4,5- tetrabromobenzoate (EH-TBB) showed notable contributions to the BFR profile in cat hair. A worst-case dust exposure estimation was performed for all analytes. The estimated TCIPP daily intake through dust ingestion was up to 1,240 ng/kg bw for toddlers. The results indicate that OPFRs are ubiquitous in South African indoor environment. Indoor dust is a major source of human exposure to environmental contaminants. This can for example occur through hand-to-mouth contact of toddlers, and is an important route of exposure to currently used FRs accumulated on dust particles. The presence of FRs, in particular high concentrations of OPFRs, suggests that children and indoor pet cats may have greater exposure to FRs than adults.

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.

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.

Rosa roxburghii supplementation in a controlled feeding study increases plasma antioxidant capacity and glutathione redox state.

BACKGROUND: Rosa roxburghii (RR) is a plant of which the fruit juice has been used as a medicinal remedy for a variety of diseases. It has been proposed that the putative beneficial properties are related to its antioxidant potential. AIM OF STUDY: We investigated the contribution of a supplemented RR fruit sample on the antioxidant status in a cohort of healthy humans. METHODS: A total of 36 young, healthy and non-smoking individuals were recruited for this randomised placebo-controlled, single-blind trial. The study was diet controlled over a five-week period with a two week run-in period before participants daily received a placebo or an encapsulated supplement of RR sample. Total antioxidant capacity, glutathione redox state, glutathione reductase, glutathione peroxidase, superoxide dismutase and 8-OHdG levels were measured. RESULTS: RR supplementation significantly increased plasma antioxidant capacity (p = 0.04) and GSH:GSSG ratios in blood (p = 0.03). No significant changes in 8-OHdG levels, total glutathione levels or antioxidant modulating enzymes were detected suggesting that the observed shift of the glutathione redox state probably occurs via the antioxidant mediated protection of GSH. CONCLUSIONS: We conclude that these findings support the putative beneficial properties that have been linked to Rosa roxburghii as a dietary supplement that can enhance antioxidant status.