School of Physics (Reports)

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  • Publication
    Evaluation of hand-held XRF for screening waste articles for exceedances of limit values for brominated flame retardants
    (Environmental Protection Agency, 2019-03) Harrad, Stuart; Drage, Daniel; Abdallah, Mohamed; Sharkey, Martin; Berresheim, Harald; Department of Communications, Climate Action and Environment, Ireland; Environmental Protection Agency
    Recent research has demonstrated the presence of restricted persistent organic pollutant (POP) brominated flame retardants (BFRs) in items such as children s toys and food contact articles. As the presence of these contaminants in such items serves no useful purpose, they are thought to originate from the use of recycled plastics that were originally treated with BFRs. To address this issue, European Union (EU) Regulation 850/2004 specifies low POP concentration limit (LPCL) values such that articles containing such BFRs [selected polybrominated diphenyl ethers (PBDEs) and hexabromocyclododecane (HBCDD)] at concentrations exceeding the LPCL (1000mg/kg) cannot be recycled and must be treated so that the BFR content of such articles is destroyed. Existing LPCLs for PBDEs cover PBDEs present in the penta- and octa-brominated diphenyl ether (BDE) formulations, with an LPCL for deca-BDE at a similar concentration scheduled for implementation from March 2019. Given the widespread use of PBDEs and HBCDD in applications such as electrical and electronic goods, polystyrene building insulation foam, seating foam and fabrics in homes, offices and cars, monitoring compliance with LPCLs represents a substantial undertaking, compounded by conventional methods for measuring PBDEs and HBCDD being destructive, timeconsuming, expensive and incompatible with being conducted in situ at waste handling sites. Our principal objective was thus to evaluate the feasibility of using hand-held X-ray fluorescence (XRF) spectrometers to determine bromine in waste articles as a surrogate indicator of exceedance of LPCLs. Of particular concern is the incidence of false positives (where the concentration of bromine but not PBDEs or HBCDD exceeds the LPCL) and false negatives (where the concentration of PBDEs or HBCDD exceeds the LPCL but this is not indicated by the bromine concentration recorded by XRF). False positives may occur when a BFR other than a PBDE or a HBCDD (e.g. tetrabromobisphenol A) is present at a concentration above 1000mg/kg. We measured bromine in 769 waste articles and PBDEs and HBCDD in 538 of the same articles collected in Ireland between 2015 and 2016. These articles comprised waste electronic and electrical equipment (WEEE), polystyrene building insulation and end-of-life vehicle foams and fabrics, as well as waste carpets, curtains, furniture foams and fabrics. Measurements revealed concentrations of PBDEs and HBCDD exceeding existing LPCLs in 29 of 538 articles (5.4%). Anticipating the introduction of an LPCL for deca-BDE (BDE-209), we found that the proportion of articles exceeding either existing LPCLs or the anticipated LPCL of 1000mg/kg for BDE-209 was 8.7% (47/538). By comparison, false positives numbered 52 (9.7%) when existing LPCLs only were considered, reducing to 34 (6.3%) when the anticipated LPCL for BDE-209 was accounted for. No false negatives were detected. Based on our data, enforcement of existing LPCLs would prevent 97.9% of the estimated 17,721kg/year of HBCDD, penta-BDEs and octa-BDEs generated currently in Ireland, as well as 13.0% of the 15,284kg/year of BDE-209 generated, from being recycled. Enforcement of an LPCL of 1000mg/kg for BDE-209 would prevent recycling of 98.1% of the 33,004kg/year of PBDEs and HBCDD currently generated in Ireland. Although false positives will lead to some articles being incorrectly prevented from being recycled, the absence of false negatives in this study, combined with the cost- and time-effectiveness of hand-held XRF relative to conventional methods for measuring PBDEs and HBCDD, renders hand-held XRF potentially feasible for large-scale monitoring of LPCL compliance. Despite this, use of hand-held XRF to screen individual waste articles may still be considered overly time-consuming by waste treatment professionals. Consequently, automation of the screening process using a fixed/bench-top XRF instrument in conjunction with a conveyor belt carrying waste articles is considered a feasible approach for large-scale waste handling operations, albeit one requiring greater capital outlay. Short-term approaches to minimise the number of articles requiring checking for compliance with LPCLs merit consideration. These involve using data from this project that show very low BFR concentrations and no exceedances of current or anticipated LPCLs for some waste categories such as extruded polystyrene (XPS) building insulation foam. On-site separation of XPS from expanded polystyrene (EPS) foam (for which 35% of samples were found to exceed the LPCL for HBCDD) to allow recycling or reuse of XPS without checking for LPCL compliance would reduce the monitoring burden placed on the waste management industry.
  • Publication
    Report No: 343: Elucidating levels and pathways of human exposure in Ireland to brominated flame retardants and perfluoroalkyl substances, ELEVATE project highlights video
    (Environmental Protection Agency, 2020-09-25) Coggins, Marie A.; Department of Communications, Climate Action and Environment, Ireland
    Brominated flame retardants (BFRs) and perfluoroalkyl substances (PFASs) have been used extensively in applications such as electrical goods, soft furnishings and building insulation foam. The ELEVATE project generated data to facilitate the assessment of human exposure to these chemicals.
  • Publication
    Report No: 343: Elucidating levels and pathways of human exposure in Ireland to brominated flame retardants and perfluoroalkyl substances
    (Environmental Protection Agency, 2020-09-25) Harrad, Stuart; Drage, Daniel; Abdallah, Mohamed; Wemken, Nina; Coggins, Marie; Department of Communications, Climate Action and Environment, Ireland
    Brominated flame retardants (BFRs) and perfluoroalkyl substances (PFASs) have found extensive use in consumer applications such as electrical and electronic goods, soft furnishings, and building insulation foam to impart properties such as flame retardancy and stain resistance. Such use has led to environmental contamination and human exposure. Owing to concerns about their environmental persistence, ability to bioaccumulate and potential adverse health effects in humans and wildlife, some BFRs and PFASs have been listed under the Stockholm Convention on Persistent Organic Pollutants (POPs), an international treaty designed to eliminate POPs from the environment. Previous studies have revealed low levels of BFRs and PFASs in Irish foodstuffs and human milk. However, no such data existed for Ireland prior to this project about the presence of both BFRs and PFASs in indoor air and dust, and of PFASs in drinking water. This project therefore measured selected BFRs and PFASs in indoor air and dust from Irish homes, offices, cars, and school classrooms (n=30 per microenvironment category). The same contaminants were measured in 16 samples of human milk donated by Irish mothers, created from samples from 92 individuals. PFASs were also measured in samples of Irish tap (n=85) and bottled water (n=31). Comparison of concentrations of BFRs in human milk in this study and in a previous Irish study conducted in 2011, reveal restrictions on the manufacture and use of hexabromocyclododecane and both the Penta- and Octa-bromodiphenyl ether products appear to have been successful in reducing concentrations in Irish human milk. Likely as a consequence of the more recent ban on manufacture and use of the Deca-BDE product, concentrations in human milk in this study show no significant decline compared 2011. Moreover, while in 2011, decabromodiphenyl ethane (DBDPE) - a likely replacement for Deca-BDE - was not detected in any human milk sample, DBDPE was detected in 3 samples in this study. This implies increasing use of DBDPE as a drop-in replacement for Deca-BDE, and is supported by our findings that concentrations of DBDPE in both indoor air and dust in this study are the highest reported to date anywhere. While this is likely because this study is one of the few conducted since the listing of Deca-BDE under the Stockholm Convention and that future studies elsewhere will likely reveal similarly elevated concentrations of DBDPE; it suggests further research into exposure to DBDPE and its health effects is a priority. With respect to PFASs, perfluorooctanoic acid (PFOA) dominated air and drinking water, while perfluorobutane sulfonate (PFBS) dominated dust. PFOS concentrations in classroom air exceeded significantly those in homes. Concentrations of PFOA, perfluorononanoic acid (PFNA), and methyl perfluorooctane sulfonamido ethanol (MeFOSE) in air, were significantly higher in cars containing child car seats than in cars without. PFOS, PFOA, PFBS, and perfluorohexane sulfonate (PFHxS) were all detected frequently in drinking water but concentrations of PFASs were low, and although PFASs were 64 ng/L in one bottled water sample, this fell below a Swedish Action Level of 90 ng PFASs/L. The Irish population s exposure to PFOS and PFOA via non-dietary sources is well below estimates of dietary exposure elsewhere in Europe. Moreover, even under a high-end exposure scenario, it falls below the European Food Safety Authority s (EFSA) provisional tolerable weekly intakes (TWIs) for PFOS and PFOA. Concentrations of PFOA, PFOS, PFHxS, and PFNA in Irish human milk are within the range of those reported elsewhere in the world. Other PFASs were not detected in human milk. Reassuringly, concentrations of PFOS and PFOA in Irish human milk currently do not indicate a health concern, based on breastfeeding exposure scenarios carried out by EFSA. Application of a simple pharmacokinetic model suggests current adult exposure in Ireland to PFOS is below EFSA s provisional TWI. In contrast, the model predicts that the maximum concentration detected in human milk in this study, implies a level of adult exposure that would exceed EFSA s provisional TWI for PFOA. Given that the health effects of PFASs other than PFOS and PFOA are currently under review by EFSA and that this study found non-dietary exposure of children to PFBS exceeds that of the other PFASs targeted in this study, it is recommended that as well as continuing to measure PFOS and PFOA, future research should also monitor exposure to other PFASs such as PFBS, as well as PFHxS and PFNA that were detected in human milk.
  • Publication
    Pilot study to investigate indoor air quality (IAQ) in energy efficient homes in Ireland: Report prepared for EPA STRIVE and Sustainable Energy Authority of Ireland
    (School of Physics, NUI Galway, 2010-09) Coggins, Marie; Byrne, Miriam; Kleefeld, Silke; Environmental Protection Agency
    Within this pilot study a number of Indoor air pollutants were measured in five energy efficient homes built to enhanced standards of air tightness of between 0.75 m3 /hr/m2 and 8.75 m3 /hr/m2 . The five homes were built according to the requirements of the 2007 Building Regulations. The objective was to evaluate whether increased standards of air tightness impacts on the indoor air quality and thermal comfort the home. The selected homes were a mixture of 3- and 4-bedroom semi-detached houses, and were occupied. Two of the houses had mechanical ventilation with heat recovery (MVHR) system, while the other three houses used natural ventilation. Indoor air quality measurements of selected pollutants, i.e. particulates (PM2.5, PM10) , nitrogen dioxide, formaldehyde, total volatile organic carbon, carbon monoxide and dust mite concentrations, and thermal comfort parameters, i.e. temperature and relative humidity, were carried out over sampling periods of 24 hours, 7 days and 14 days, respectively. In addition, air exchange rates of selected rooms within each individual home were established. Diary records of occupant activities and household questionnaires on the homes and their indoor environment were also collected. In general the levels of pollutants measured in this project were within recommended guideline limits. Variations in pollutant concentrations could in most cases, be correlated to certain activities within the individual homes, like for example cooking, smoking, or redecorating. However as this was a small scale project it is difficult to draw definitive conclusions regarding the impact of increased air tightness on indoor air quality and thermal comfort. A larger scale study, building on the findings of this pilot project, is recommended. There is a lack of data internationally on indoor air quality in highly energy efficient homes. A larger scale project should include a broader range of building types such as detached or terraced houses and apartments etc. and should also include a larger number of homes which use energy saving technologies such as MHVR. This study would also look at how indoor air concentrations vary by season, it is likely that higher concentrations maybe found in the winter period, during periods of maximum fuel use and maximum occupancy. A larger study would also include a qualitative element such as a National survey, of key stakeholders working in this area. The aim of the survey would be to collect information on the le vel of knowledge, the usability and suitability of the energy technologies available to home owners today. Experiences gained in this project, seemed to suggest that there is a lack of knowledge among some members of public on what energy efficient technologies are available and it was difficult to find 3 or 4 bed semi detached homes who were using energy saving technologies to participate in this pilot study.
  • Publication
    The study of neutron star magnetospheres with LOFT
    (2015) Shearer, Andrew; |~|
    The Large Observatory for X-ray Timing, LOFT, is designed to perform fast X-ray timing and spectroscopy with uniquely large throughput (Feroci et al. 2014). LOFT focuses on two fundamental questions of ESA’s Cosmic Vision Theme “Matter under extreme conditions”: what is the equation of state of ultradense matter in neutron stars? Does matter orbiting close to the event horizon follow the predictions of general relativity? These goals are elaborated in the mission Yellow Book ( 53447-loft-yellow-book/) describing the LOFT mission as proposed in M3, which closely resembles the LOFT mission now being proposed for M4. The extensive assessment study of LOFT as ESA’s M3 mission candidate demonstrates the high level of maturity and the technical feasibility of the mission, as well as the scientific importance of its unique core science goals. For this reason, the LOFT development has been continued, aiming at the new M4 launch opportunity, for which the M3 science goals have been confirmed. The unprecedentedly large effective area, large grasp, and spectroscopic capabilities of LOFT’s instruments make the mission capable of state-of-the-art science not only for its core science case, but also for many other open questions in astrophysics. LOFT’s primary instrument is the Large Area Detector (LAD), a 8.5m2 instrument operating in the 2–30 keV energy range, which will revolutionise studies of Galactic and extragalactic X-ray sources down to their fundamental time scales. The mission also features a Wide Field Monitor (WFM), which in the 2–50 keV range simultaneously observes more than a third of the sky at any time, detecting objects down to mCrab fluxes and providing data with excellent timing and spectral resolution. Additionally, the mission is equipped with an on-board alert system for the detection and rapid broadcasting to the ground of celestial bright and fast outbursts of X-rays (particularly, Gamma-ray Bursts). This paper is one of twelve White Papers that illustrate the unique potential of LOFT as an X-ray observatory in a variety of astrophysical fields in addition to the core science.
  • Publication
    Whitecaps and the marine atmosphere, report no. 6
    (1984-06) Doyle, David M.; Office of Naval Research, U.S. Department of the Navy, Grant N00014-78-G0052.
    This study is concerned with the interdependence of 10m elevation wind speed, oceanic whitecap coverage and marine aerosol concentration. The field work is divided into two distinct phases. On Inishmore Co. Galway. aerosol concentrations and ambient meteorological conditions were monitored, at a coastal site, over a two year period. The station is described. The dependence of the concentration of the 'Large' and 'Giant' aerosol components of the marine atmosphere on wind speed, wind direction and other factors is discussed. The relationship of Giant maritime particles to wind speed is N(2.5+) = 5.34 x 10(3)U(1.39) The STREX experiment took place in the Gulf of Alaska, from mid-October to mid-December 1980. The influence of such factors as 10m elevation wind speed, sea-surface temperature, and atmospheric.stability on whitecap coverage and on the concomitant production of marine aerosol particles is evaluated. The degree of oceanic whitecap cover was estimated photographically. The relationship between oceanic whitecap coverage, W, and wind speed, U, is W = 6.22 x 10(-3)3U(2.21) There is an enhancement of the positive dependence of aerosol concentration upon whitecap cover with increasing droplet radius. Both the Inishmore and STREX results are compared to previously published data sets. They are also compared to each other. The results of these comparisons are, in general, quite favourable.
  • Publication
    Whitecaps and the marine atmosphere, report no. 3
    (1981-04) Spillane, M. C.; O'Muircheartalgh, I.G.; Monahan, E.C.; Office of Naval Research, U.S. Department of the Navy, Grant NODD14-78-G-0052, Modification No. P00002.
    This report covers the period from 1 July, 1980 to 31 March, 1981, and is devoted to a description of the work carried out, and the results obtained, during this interval on the on-going ONR-sponsored study of "The Influence of Whitecaps on the Marine Atmosphere". The publications to date resulting from the whitecap project are listed in Table 1.1., with those numbered from 10 onward relating specifically to the period covered by this report. The full text of the paper delivered on 28 July, 1980 in Manchester at the VI International Conference on Atmospheric Electricity (item 10) is included as Chapter 2 of this report (an abstract of this paper appeared in the July 1980 report to ONR, i.e. in item 9). The note submitted in January, 1981 to the JASIN News (item 12) is reproduced as Chapter 7 of the present report.
  • Publication
    Whitecaps and the marine atmosphere, report no. 8
    (1985-10) Monahan, E. C.; Office of Naval Research, U.S. Department of the Navy, Grant N00014-78-G - 0052 (NR211-229), Modi fication No. P00007
    During the 12-month-long period covered by this report, i.e. in the 1 October 1984 - 30 September interval, all facets of the Whitecap Project progressed apace. The field work during this year included both international and local measurement programmes. Data were obtained in the North Sea during the HEXOS Meetpost Noordwijk experiment, and along the west coast of Ireland, aboard the LOUGH BELTRA and at the Gort na gCapall field station on Inishmore. The effect of changes in water temperature on the aerosol productivity of whitecaps was investigated using the whitecap simulation tank. A detailed study of the production of condensation nuclei by whitecaps was carried out in this tank in co-operation with a colleague from t he State University of New York at Albany.
  • Publication
    Whitecaps and the marine atmosphere, report no. 5
    (1983-06) Monahan, E. C.; Office of Naval Research, u.s. Department of the Navy, Grant N00014-78-G-OOS2 1 (NR211-229), Modifications No. P00002, POOOOJ, P00004 and POOOOS
    During this year we have continued making measurements of aerosols and electrostatic charge from our coastal tower in Gort na gCapall on Inishmore. Likewise, the experiments centred on the Whitecap Simulation Tank are continuing. In addition, a number of modifications to the Whitecap Simulation Tank and aerosol hood have been carried out in preparation for the UCG/NPS Whitecap Simulation Tank Experiments, IV, now scheduled to be held in September 1983.
  • Publication
    Whitecaps and the marine atmosphere, report no. 7
    (1984-10) Monahan, E. C.; Office of Naval Research, U.S. Department of the Navy, Grant N00014-78-G-0052, {NR2ll-229), Modifications No. POOOOS and P00006
    This report describes the general activities and findings of the Whitecap Project in the 16-month-long period 1 June 1983-30 September 1984. Additional results obtained during this period from this study of whitecaps and the marine atmosphere are to be found in Report No . 6 (Marine Aerosol Research in the Gulf of Alaska and on the Irish West Coast (Inishmore), written by D.M . Doyle and issued in June 1984. The research emphasis during the period covered by the present report was on the collection of whitecap (and aerosol and electrostatic charge) data, primarily in cold water regimes.