18 research outputs found

    Contributions of wood smoke and vehicle emissions to ambient concentrations of volatile organic compounds and particulate matter during the Yakima wintertime nitrate study

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    A multiple linear regression (MLR) chemical mass balance model was applied to data collected during an air quality field experiment in Yakima, WA, during January 2013 to determine the relative contribution of residential wood combustion (RWC) and vehicle emissions to ambient pollutant levels. Acetonitrile was used as a chemical tracer for wood burning and nitrogen oxides (NOx) as a chemical tracer for mobile sources. RWC was found to be a substantial source of gas phase air toxics in wintertime. The MLR model found RWC primarily responsible for emissions of formaldehyde (73%), acetaldehyde (69%), and black carbon (55%) and mobile sources primarily responsible for emissions of carbon monoxide (CO; 83%), toluene (81%), C2-alkylbenzenes (81%), and benzene (64%). When compared with the Environmental Protection Agency’s 2011 winter emission inventory, the MLR results suggest that the contribution of RWC to CO emissions was underestimated in the inventory by a factor of 2. Emission ratios to NOx from the MLR model agreed to within 25% with wintertime emission ratios predicted from the Motor Vehicle Emissions Simulator (MOVES) 2010b emission model for Yakima County for all pollutants modeled except for CO, C2-alkylbenzenes, and black carbon. The MLR model results suggest that MOVES was overpredicting mobile source emissions of CO relative to NOx by a factor of 1.33 and black carbon relative to NOx by about a factor of 3

    Differences in BVOC oxidation and SOA formation above and below the forest canopy

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    Gas-phase biogenic volatile organic compounds (BVOCs) are oxidized in the troposphere to produce secondary pollutants such as ozone (O3), organic nitrates (RONO2), and secondary organic aerosol (SOA). Two coupled zero-dimensional models have been used to investigate differences in oxidation and SOA production from isoprene and α-pinene, especially with respect to the nitrate radical (NO3), above and below a forest canopy in rural Michigan. In both modeled environments (above and below the canopy), NO3 mixing ratios are relatively small (< 0.5 pptv); however, daytime (08:00–20:00 LT) mixing ratios below the canopy are 2 to 3 times larger than those above. As a result of this difference, NO3 contributes 12 % of total daytime α-pinene oxidation below the canopy while only contributing 4 % above. Increasing background pollutant levels to simulate a more polluted suburban or peri-urban forest environment increases the average contribution of NO3 to daytime below-canopy α-pinene oxidation to 32 %. Gas-phase RONO2 produced through NO3 oxidation undergoes net transport upward from the below-canopy environment during the day, and this transport contributes up to 30 % of total NO3-derived RONO2 production above the canopy in the morning (∼ 07:00). Modeled SOA mass loadings above and below the canopy ultimately differ by less than 0.5 µg m−3, and extremely low-volatility organic compounds dominate SOA composition. Lower temperatures below the canopy cause increased partitioning of semi-volatile gas-phase products to the particle phase and up to 35 % larger SOA mass loadings of these products relative to above the canopy in the model. Including transport between above- and below-canopy environments increases above-canopy NO3-derived α-pinene RONO2 SOA mass by as much as 45 %, suggesting that below-canopy chemical processes substantially influence above-canopy SOA mass loadings, especially with regard to monoterpene-derived RONO2

    Lockdown during the COVID-19 pandemic: impact on infants with pyloric stenosis

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    The COVID-19 pandemic has posed challenges for the delivery of healthcare for infants with disruption to 6-week health checks and health visitor services.1 An area of particular concern is late presentation to the hospital.2 However, current data do not offer an objective picture of how significant a problem this may be, with other reports showing low rates of delays in presentation.3 Infantile hypertrophic pyloric stenosis (IHPS) is a common, non-infective infantile condition with a predictable clinical course and therefore a good indicator condition to assess for delays in presentation. We aimed to assess whether infants with IHPS presented later during ‘lockdown’ compared with the same period the preceding year

    Developing an Australian Melanoma Clinical Outcomes Registry (MelCOR): a protocol paper

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    Introduction Australia has the highest incidence of melanoma in the world with variable care provided by a diverse range of clinicians. Clinical quality registries aim to identify these variations in care and provide anonymised, benchmarked feedback to clinicians and institutions to improve patient outcomes. The Australian Melanoma Clinical Outcomes Registry (MelCOR) aims to collect population-wide, clinical-level data for the early management of cutaneous melanoma and provide anonymised feedback to healthcare providers. Methods and analysis A modified Delphi process will be undertaken to identify key clinical quality indicators for inclusion in the MelCOR pilot. MelCOR will prospectively collect data relevant to these quality indicators, initially for all people over the age of 18 years living in Victoria and Queensland with a melanoma diagnosis confirmed by histopathology, via a two-stage recruitment and consent process. In stage 1, existing State-based cancer registries contact the treating clinician and provide an opportunity for them to opt themselves or their patients out of direct contact with MelCOR. After stage 1, re-identifiable clinical data are provided to the MelCOR under a waiver of consent. In stage 2, the State-based cancer registry will approach the patient directly and invite them to opt in to MelCOR and share identifiable data. If a patient elects to opt in, MelCOR will be able to contact patients directly to collect patient-reported outcome measures. Aggregated data will be used to provide benchmarked, comparative feedback to participating institutions/clinicians. Ethics and dissemination Following the successful collection of pilot data, the feasibility of an Australia-wide roll out will be evaluated. Key quality indicator data will be the core of the MelCOR dataset, with additional data points added later. Annual reports will be issued, first to the relevant stakeholders followed by the public. MelCOR is approved by the Alfred Ethics Committee (58280/127/20)

    Principles for using evidence to improve biodiversity impact mitigation by business

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    There is an increasing expectation on the private sector to address biodiversity impacts and contribute towards global conservation goals. Appropriate evidence use can help businesses avoid biodiversity losses and realise gains, reduce resources wasted on ineffective or suboptimal action, whilst minimising biodiversity-related risks and securing opportunities from engaging with biodiversity. We review the status of evidence-based action in the private sector, where previous studies have identified concerning trends, and explore the barriers that may currently be hindering evidence use. To learn from this, and improve evidence use, we propose a set of principles for evidence-based biodiversity impact mitigation. We outline tools and resources that can help businesses move towards evidence-based practice and achieve each of these principles. Meeting these principles would improve the biodiversity outcomes from business’ biodiversity related actions. However, for business action to contribute more fully to global conservation goals, broader political and socio-economic issues also need addressing

    Lockdown during the COVID-19 pandemic: impact on infants with pyloric stenosis

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    The COVID-19 pandemic has posed challenges for the delivery of healthcare for infants with disruption to 6-week health checks and health visitor services.1 An area of particular concern is late presentation to the hospital.2 However, current data do not offer an objective picture of how significant a problem this may be, with other reports showing low rates of delays in presentation.3 Infantile hypertrophic pyloric stenosis (IHPS) is a common, non-infective infantile condition with a predictable clinical course and therefore a good indicator condition to assess for delays in presentation. We aimed to assess whether infants with IHPS presented later during ‘lockdown’ compared with the same period the preceding year.Ten centres within the UK (England, Scotland and Northern Ireland) contributed data from babies with IHPS via a website (covidinchildren.co.uk) between 23 March 2020 and 31 May 2020 (the COVID-19 lockdown period) and between 23 March and 31 May 2019 (controls). A total of 87 eligible infants were included, comprising 40 controls (46%) and 47 cases (54%). The demographic and baseline characteristics of the two groups were similar (table 1 and figure 1).<br/
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