Publications
47 results found
Ngo KQ, Hoang LA, Ho BQ, et al., 2023, Street-scale dispersion modelling framework of road-traffic derived air pollution in Hanoi, Vietnam., Environ Res, Vol: 233
Traffic is an important source of air pollution in Vietnamese cities. The spatio-temporal variation of air pollution derived from traffic is poorly understood. Application of dispersion modelling can help but is hindered by the local scarcity of suitable input data. This study fills the data gap, by establishing a framework employing open-access global data to model emission from traffic activities in Hanoi. The outlined methodology explicitly defines road sources, calculates their emission, and employs background pollution profiles from Copernicus Atmospheric Monitoring Service (CAMS) to produce street-scale distribution maps for CO, PM10 and PM2.5. Pollution hotspots are found near major traffic flows with the highest hourly average CO, PM10 and PM2.5 concentrations at 1206, 87.5 and 61.5 μgm-3, respectively. The relationship between concentrations and properties of the road network is assessed. Motorcycles are the main emitters of the traffic sector. Emission from Heavy Good Vehicles dominate during the night, with contribution percentages increase as it gets further away from the city core. Modelled concentrations are underestimated mainly due to low vehicular emission factor. Adjusting emission factors according to vehicle quality in Vietnam greatly improves agreement. The presence of non-traffic emission sources contributes to the model underestimation. Results for comparisons of daily averaged PM values are broadly in agreement between models and observations; however, diurnal patters are skewed. This results partly from the uncertainties linked with background pollution levels from CAMS, and partly from non-traffic sources which are not accounted for here. Further work is needed to assess the use of CAMS's concentrations in Vietnam. Meteorological input contributes to the temporal disagreement between the model and observations. The impact is most noticeable with CO concentrations during morning traffic rush hours. This study recommends approaches to
Hodoli CG, Coulon F, Mead M, 2023, Source identification with high-temporal resolution data from low-cost sensors using bivariate polar plots in urban areas of Ghana, ENVIRONMENTAL POLLUTION, Vol: 317, ISSN: 0269-7491
Khokhar MF, Anjum MS, Salam A, et al., 2022, Recurring South Asian smog episodes: Call for regional cooperation and improved monitoring, ATMOSPHERIC ENVIRONMENT, Vol: 295, ISSN: 1352-2310
Mead MI, Bevilacqua M, Loiseaux C, et al., 2022, Generalised network architectures for environmental sensing: Case studies for a digitally enabled environment, Array, Vol: 14
A digitally enabled environment is a setting which incorporates sensors coupled with reporting and analytics tools for understanding, observing or managing that environment. Large scale data collection and analysis are a part of the emerging digitally enabled approach for the characterisation and understanding of our environment. It is recognised as offering an effective methodology for addressing a range of complex and interrelated social, economic and environmental concerns. The development and construction of the approach requires advances in analytics control linked with a clear definition of the issues pertaining to the interaction between elements of these systems. This paper presents an analysis of selected issues in the field of analytics control. It also discusses areas of progress, and areas in need of further investigation as sensing networks evolve. Three case studies are described to illustrate these points. The first is a physical analytics test kit developed as a part of the “Reinvent the Toilet Challenge” (RTTC) for process control in a range of environments. The second case study is the Cranfield Urban Observatory that builds on elements of the RTTC and is designed to allow users to develop user interfaces to monitor, characterise and compare a variety of environmental and infrastructure systems plus behaviours (e.g., water distribution, power grids). The third is the Data and Analytics Facility for National Infrastructure, a cloud-based high-performance computing cluster, developed to receive, store and present such data to advanced analytical and visualisation tools.
Khokhar MF, 2021, Countries of the Indo-Gangetic Plain must unite against air pollution, NATURE, Vol: 598, Pages: 415-415, ISSN: 0028-0836
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- Citations: 4
Mohyeddin N, Abu Samah A, Chenoli SN, et al., 2020, The effects of synoptic and local meteorological condition on CO2, CH4, PM(10)and PM(2.5)at Bachok Marine Research Station (BMRS) in Peninsular Malaysia, METEOROLOGY AND ATMOSPHERIC PHYSICS, Vol: 132, Pages: 845-868, ISSN: 0177-7971
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- Citations: 3
Alifa M, Bolster D, Mead MI, et al., 2020, The influence of meteorology and emissions on the spatio-temporal variability of PM10 in Malaysia, ATMOSPHERIC RESEARCH, Vol: 246, ISSN: 0169-8095
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- Citations: 6
Bruni Zani N, Lonati G, Mead M, et al., 2020, Long-term satellite-based estimates of air quality and premature mortality in Equatorial Asia through deep neural networks, ENVIRONMENTAL RESEARCH LETTERS, Vol: 15, ISSN: 1748-9326
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- Citations: 5
Hodoli CG, Coulon F, Mead MI, 2020, Applicability of factory calibrated optical particle counters for high -density air quality monitoring networks in Ghana, HELIYON, Vol: 6
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- Citations: 6
Bolas CG, Ferracci V, Robinson AD, et al., 2020, iDirac: a field-portable instrument for long-term autonomous measurements of isoprene and selected VOCs, ATMOSPHERIC MEASUREMENT TECHNIQUES, Vol: 13, Pages: 821-838, ISSN: 1867-1381
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- Citations: 6
Shaw JT, Allen G, Pitt J, et al., 2019, A baseline of atmospheric greenhouse gases for prospective UK shale gas sites, SCIENCE OF THE TOTAL ENVIRONMENT, Vol: 684, Pages: 1-13, ISSN: 0048-9697
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- Citations: 12
Bolas CG, Ferracci V, Robinson AD, et al., 2019, iDirac: a field-portable instrument for long-term autonomousmeasurements of isoprene and selected VOCs
<jats:p>Abstract. The iDirac is a new instrument to measure selected hydrocarbons in the remote atmosphere. A robust design is central to its specifications, with portability, power efficiency, low gas consumption and autonomy as the other driving factors in the instrument development. The iDirac is a dual-column isothermal oven gas chromatograph with photoionisation detection (GC-PID). The instrument is designed and built in-house. It features a modular design, with novel use of open-source technology for accurate instrument control. Currently configured to measure biogenic isoprene, the system is suitable for a range of compounds. For isoprene measurements in the field, the instrument precision (relative standard deviation) is ± 11 %, with a limit of detection down to 38 pmol mol−1 (or ppt). The instrument was first tested in the field in 2015 in a ground-based campaign, and has since shown itself suitable for deployment in a variety of environments and platforms. This paper describes the instrument design, operation and performance based on laboratory tests in a controlled environment, and during deployments in forests in Malaysian Borneo and in Central England. </jats:p>
Allen G, Hollingsworth P, Kabbabe K, et al., 2019, The development and trial of an unmanned aerial system for the measurement of methane flux from landfill and greenhouse gas emission hotspots, WASTE MANAGEMENT, Vol: 87, Pages: 883-892, ISSN: 0956-053X
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- Citations: 42
Farren NJ, Dunmore RE, Mead MI, et al., 2019, Chemical characterisation of water-soluble ions in atmospheric particulate matter on the east coast of Peninsular Malaysia, ATMOSPHERIC CHEMISTRY AND PHYSICS, Vol: 19, Pages: 1537-1553, ISSN: 1680-7316
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- Citations: 22
Popoola OAM, Carruthers D, Lad C, et al., 2018, Use of networks of low cost air quality sensors to quantify air quality in urban settings, Atmospheric Environment, Vol: 194, Pages: 58-70, ISSN: 1352-2310
Low cost sensors are becoming increasingly available for studying urban air quality. Here we show how such sensors, deployed as a network, provide unprecedented insights into the patterns of pollutant emissions, in this case at London Heathrow Airport (LHR). Measurements from the sensor network were used to unequivocally distinguish airport emissions from long range transport, and then to infer emission indices from the various airport activities. These were used to constrain an air quality model (ADMS-Airport), creating a powerful predictive tool for modelling pollutant concentrations. For nitrogen dioxide (NO2), the results show that the non-airport component is the dominant fraction (∼75%) of annual NO2 around the airport and that despite a predicted increase in airport related NO2 with an additional runway, improvements in road traffic fleet emissions are likely to more than offset this increase. This work focusses on London Heathrow Airport, but the sensor network approach we demonstrate has general applicability for a wide range of environmental monitoring studies and air pollution interventions.
Farren NJ, Dunmore RE, Mead MI, et al., 2018, Chemical Characterisation of Water-soluble Ions in Atmospheric Particulate Matter on the East Coast of Peninsular Malaysia
<jats:p>Abstract. Air quality on the east coast of Peninsular Malaysia is influenced by local anthropogenic and biogenic emissions, as well as marine air masses from the South China Sea and aged emissions transported from highly polluted East Asian regions during the winter monsoon season. An atmospheric observation tower has been constructed on this coastline at the Bachok Marine and Atmospheric Research Station. Daily PM2.5 samples were collected from the top of the observation tower over a 3-week period, and ion chromatography was used to make time-resolved measurements of major atmospheric ions present in aerosol. SO42− was found to be the most dominant ion present, and on average made up 66 % of the total ion content. Predictions of aerosol pH were made using the ISOROPPIA-II thermodynamic model and it was estimated that the aerosol was highly acidic, with pH values ranging from −0.97 to 1.12. A clear difference in aerosol composition was found between continental air masses originating from industrialised regions of East Asia and marine air masses predominantly influenced by the South China Sea. For example, elevated SO42− concentrations and increased Cl− depletion was observed when continental air masses that had passed over highly industrialised regions of East Asia arrived at the measurement site. Correlation analyses of the ionic species and assessment of ratios between different ions provided an insight into common sources and formation pathways of key atmospheric ions, such as SO42−, NH4+ and C2O42−. To our knowledge, time-resolved measurements of water-soluble ions in PM2.5 are virtually non-existent in rural locations on the east coast of Peninsular Malaysia; overall this dataset contributes towards a better understanding of atmospheric composition in the Maritime Continent, a region of the tropics that is vulnerable to the effects of poor air quality, largely as a result of rapid industrialisation in Ea
Farren NJ, Dunmore RE, Mead MI, et al., 2018, Supplementary material to &quot;Chemical Characterisation of Water-soluble Ions in Atmospheric Particulate Matter on the East Coast of Peninsular Malaysia&quot;
Mead MI, Castruccio S, Latif MT, et al., 2018, Impact of the 2015 wildfires on Malaysian air quality and exposure: a comparative study of observed and modeled data, ENVIRONMENTAL RESEARCH LETTERS, Vol: 13, ISSN: 1748-9326
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- Citations: 17
Nadzir MSM, Ashfold MJ, Khan MF, et al., 2018, Spatial-temporal variations in surface ozone over Ushuaia and the Antarctic region: observations from in situ measurements, satellite data, and global models, ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH, Vol: 25, Pages: 2194-2210, ISSN: 0944-1344
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- Citations: 7
Hodoli CG, Abubakari A, Adzaho G, 2018, The need for open data on air quality monitoring in logistically difficult environments, Clean Air Journal, Vol: 28, ISSN: 1017-1703
Oram DE, Ashfold MJ, Laube JC, et al., 2017, A growing threat to the ozone layer from short-lived anthropogenic chlorocarbons, ATMOSPHERIC CHEMISTRY AND PHYSICS, Vol: 17, Pages: 11929-11941, ISSN: 1680-7316
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- Citations: 50
Ashfold MJ, Latif MT, Samah AA, et al., 2017, Influence of Northeast Monsoon cold surges on air quality in Southeast Asia, ATMOSPHERIC ENVIRONMENT, Vol: 166, Pages: 498-509, ISSN: 1352-2310
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- Citations: 17
Jerrett M, Donaire-Gonzalez D, Popoola O, et al., 2017, Validating novel air pollution sensors to improve exposure estimates for epidemiological analyses and citizen science, Environmental Research, Vol: 158, Pages: 286-294, ISSN: 0013-9351
Low cost, personal air pollution sensors may reduce exposure measurement errors in epidemiological investigations and contribute to citizen science initiatives. Here we assess the validity of a low cost personal air pollution sensor. Study participants were drawn from two ongoing epidemiological projects in Barcelona, Spain. Participants repeatedly wore the pollution sensor − which measured carbon monoxide (CO), nitric oxide (NO), and nitrogen dioxide (NO2). We also compared personal sensor measurements to those from more expensive instruments. Our personal sensors had moderate to high correlations with government monitors with averaging times of 1-h and 30-min epochs (r ~ 0.38–0.8) for NO and CO, but had low to moderate correlations with NO2 (~0.04–0.67). Correlations between the personal sensors and more expensive research instruments were higher than with the government monitors. The sensors were able to detect high and low air pollution levels in agreement with expectations (e.g., high levels on or near busy roadways and lower levels in background residential areas and parks). Our findings suggest that the low cost, personal sensors have potential to reduce exposure measurement error in epidemiological studies and provide valid data for citizen science studies.
Oram DE, Ashfold MJ, Laube JC, et al., 2017, A growing threat to the ozone layer from short-lived anthropogenic chlorocarbons
<jats:p>Abstract. Large and effective reductions in emissions of long-lived ozone-depleting substance (ODS) are being achieved through the Montreal Protocol, the effectiveness of which can be seen in the declining atmospheric abundances of many ODS. An important remaining uncertainty concerns the role of very short lived substances (VSLS) which, owing to their relatively short atmospheric lifetimes (less than 6 months), are not regulated under the Montreal Protocol. Recent studies have found an unexplained increase in the global tropospheric abundance of one VSLS, dichloromethane (CH2Cl2), which has increased by around 60 % over the past decade. Here we report dramatic enhancements of several chlorine-containing VSLS, including CH2Cl2 and CH2ClCH2Cl (1,2-dichloroethane), observed in surface and upper tropospheric air in East and South East Asia. Surface observations were an order of magnitude higher than previously reported in the marine boundary layer, whilst upper tropospheric data were up to 3 times higher than expected. In addition we provide further evidence of an atmospheric transport mechanism whereby substantial amounts of industrial pollution from East Asia, including these chlorinated VSLS, can rapidly, and regularly, be transported to tropical regions of the western Pacific and subsequently uplifted to the tropical upper troposphere. This latter region is a major provider for air entering the stratosphere and so this mechanism, in conjunction with increasing emissions of Cl-VSLS from East Asia, could potentially slow the expected recovery of stratospheric ozone. </jats:p>
Oram DE, Ashfold MJ, Laube JC, et al., 2017, Supplementary material to &quot;A growing threat to the ozone layer from short-lived anthropogenic chlorocarbons&quot;
Latif MT, Dominick D, Ahamad F, et al., 2016, Seasonal and long term variations of surface ozone concentrations in Malaysian Borneo, SCIENCE OF THE TOTAL ENVIRONMENT, Vol: 573, Pages: 494-504, ISSN: 0048-9697
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- Citations: 13
Popoola OAM, Stewart GB, Mead MI, et al., 2016, Development of a baseline-temperature correction methodology for electrochemical sensors and its implications for long-term stability, ATMOSPHERIC ENVIRONMENT, Vol: 147, Pages: 330-343, ISSN: 1352-2310
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- Citations: 67
Dunmore RE, Hopkins JR, Lidster RT, et al., 2016, Development of a Combined Heart-Cut and Comprehensive Two-Dimensional Gas Chromatography System to Extend the Carbon Range of Volatile Organic Compounds Analysis in a Single Instrument, SEPARATIONS, Vol: 3
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- Citations: 3
Dominick D, Latif MT, Juneng L, et al., 2015, Characterisation of particle mass and number concentration on the east coast of the Malaysian Peninsula during the northeast monsoon, ATMOSPHERIC ENVIRONMENT, Vol: 117, Pages: 187-199, ISSN: 1352-2310
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- Citations: 20
Heimann I, Bright VB, McLeod MW, et al., 2015, Source attribution of air pollution by spatial scale separation using high spatial density networks of low cost air quality sensors, ATMOSPHERIC ENVIRONMENT, Vol: 113, Pages: 10-19, ISSN: 1352-2310
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- Citations: 80
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