Characteristics of fine and ultrafine aerosols in the London underground

Kumar, Pankaj; Zavala‐Reyes, Juan C.; Kalaiarasan, Gopinath; Abubakar-Waziri, Hisham; Young, Gloria; Mudway, Ian; Dilliway, Claire; Lakhdar, Ramzi; Mumby, Sharon; Kłosowski, Michał M.; Pain, Christopher C.; Adcock, Ian M.; Watson, Jonathan S.; Sephton, M. A.; Chung, Kian Fan; Porter, Alexandra E.

doi:10.1016/j.scitotenv.2022.159315

Cited by 8 publications

(12 citation statements)

References 89 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Interestingly, we did not find virus on the samples collected on the platforms over a longer period of 8 hours. The presence of SARS-CoV2 on airborne PM picked up in the carriage but not on the platforms is of great interest because levels of PM on the London Underground are known to be very high 18 19. Previously, SARS-CoV2 virus have been detected from air samples collected between May and July 2020 inside buses and subway trains in Barcelona, Spain, particularly on PM2.5 20.…”

Section: Discussionmentioning

confidence: 99%

“…The presence of SARS-CoV2 on airborne PM picked up in the carriage but not on the platforms is of great interest because levels of PM on the London Underground are known to be very high. 18 19 Previously, SARS-CoV2 virus have been detected from air samples collected between May and July 2020 inside buses and subway trains in Barcelona, Spain, particularly on PM2.5. 20 We did not pick up virus from the other sites (university campus and primary school), possibly owing to policies in place which encourage regular testing for detection of COVID-19 infection, hence a lower likelihood of infected persons detected earlier and isolation occurring sooner.…”

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

SARS-CoV2 in public spaces in West London, UK during COVID-19 pandemic

Abubakar-Waziri

Kalaiarasan²,

Wawman

et al. 2023

BMJ Open Resp Res

Self Cite

View full text Add to dashboard Cite

BackgroundSpread of SARS-CoV2 by aerosol is considered an important mode of transmission over distances >2 m, particularly indoors.ObjectivesWe determined whether SARS-CoV2 could be detected in the air of enclosed/semi-enclosed public spaces.Methods and analysisBetween March 2021 and December 2021 during the easing of COVID-19 pandemic restrictions after a period of lockdown, we used total suspended and size-segregated particulate matter (PM) samplers for the detection of SARS-CoV2 in hospitals wards and waiting areas, on public transport, in a university campus and in a primary school in West London.ResultsWe collected 207 samples, of which 20 (9.7%) were positive for SARS-CoV2 using quantitative PCR. Positive samples were collected from hospital patient waiting areas, from hospital wards treating patients with COVID-19 using stationary samplers and from train carriages in London underground using personal samplers. Mean virus concentrations varied between 429 500 copies/m3in the hospital emergency waiting area and the more frequent 164 000 copies/m3found in other areas. There were more frequent positive samples from PM samplers in the PM2.5 fractions compared with PM10 and PM1. Culture on Vero cells of all collected samples gave negative results.ConclusionDuring a period of partial opening during the COVID-19 pandemic in London, we detected SARS-CoV2 RNA in the air of hospital waiting areas and wards and of London Underground train carriage. More research is needed to determine the transmission potential of SARS-CoV2 detected in the air.

show abstract

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

SARS-CoV2 in public spaces in West London, UK during COVID-19 pandemic

Abubakar-Waziri

Kalaiarasan²,

Wawman

et al. 2023

BMJ Open Resp Res

Self Cite

View full text Add to dashboard Cite

show abstract

“…Just over half of the studies reviewed took advantage of fixed monitoring stations in the locality and compared external pollution levels to those measured indoors (Kumar et al 2023a, 2023b, He et al 2022, a useful initiative as the variance between outdoor and indoor air quality needs to be considered on a case-by-case basis. Levels of radon and carbon monoxide, for example, can vary greatly depending on location (Miles andAppleton 2005, Holloway et al 2000).…”

Section: External Pollutant Ingressmentioning

confidence: 99%

“…Whilst models of the indoor environment most often operate under the premise of a well-mixed space, this may not always be true Chen 2007, Furtaw et al 1996), and deploying sensors at different locations within the space could provide valuable indication of pollutant sources. For example, Kumar et al (2023aKumar et al ( , 2023b conducted a study of microcharacteristics in naturally ventilated classrooms with varying sensor locations and used this information to determine appropriate placement and operation of air purifiers. Another study by Kumar et al (2023) looked at spatial distribution of PM and ventilation efficacy on the London Underground.…”

Section: External Pollutant Ingressmentioning

confidence: 99%

Indoor air quality monitoring and source apportionment using low-cost sensors

Higgins,

Kumar,

Morawska

2024

Environ. Res. Commun.

Self Cite

View full text Add to dashboard Cite

Understanding of the various sources of indoor air pollution requires indoor air quality (IAQ) data that is usually lacking. Such data can be obtained using unobtrusive, low-cost sensors (LCS). The aim of this review is to examine the recent literature published on LCS for IAQ measurements and to determine whether these studies employed any methods to identify or quantify sources of indoor air pollution. Studies were reviewed in terms of whether any methods of source apportionment were employed, as well as the microenvironment type, geographical location, and several metrics relating to the contribution of outdoor pollutant ingress versus potential indoor pollutant sources. We found that out of 60 relevant studies, just four employed methods for source apportionment, all of which utilised receptor models. Most studies were undertaken in residential or educational environments. There is a lack of data on IAQ in other types of microenvironments and in locations outside of Europe and North America. There are inherent limitations with LCS in terms of producing data which can be utilised in source apportionment models. This applies to external pollution data, however IAQ can be even more challenging to measure due to its characteristics. The indoor environment is heterogeneous, with significant variability within the space as well as between different microenvironments and locations. Sensor placement, occupancy, and activity reports, as well as measurements in different microenvironments and locations, can contribute to understanding this variability. Outdoor pollutants can ingress into the space via the building envelope, however measurement of external pollution and environmental conditions, as well as recording details on the building fabric and ventilation conditions, can help apportion external contributions. Whether or not source apportionment models are employed on indoor data from LCS, there are parameters which, if carefully considered during measurement campaigns, can aid in source identification of pollutants.

show abstract

“…Within urban areas and cities, the transport system assumes a central role in the production of particulate matter (PM) emissions, responsible for 20-40% of the total pollutant and environmental emissions (e.g., [1][2][3][4][5]). To mitigate this negative incidence, urban planners emphasize the promotion of sustainable transport policies (e.g., [6][7][8][9][10]), such as the development of high-quality underground metro systems or the retrofitting of the traditional ones (e.g., [3,[11][12][13]). Metro systems, which utilize an electrical power supply and move a high number of passengers/day, represent an effective solution to curbing greenhouse gas emissions.…”

Section: Introductionmentioning

confidence: 99%

Rain-Based Train Washing: A Sustainable Approach to Reduce PM Concentrations in Underground Environments

Cartenì,

Cascetta,

Falanga

et al. 2024

Sustainability

View full text Add to dashboard Cite

Fine particle concentrations measured in many underground rail systems around the world consistently exceed those observed at ground level, potentially posing significant implications for human health. While numerous authors have observed these high particle concentrations and analyzed both their atomic compositions and health impacts, few have investigated devices and technologies capable of reducing these high levels in underground environments. In light of these considerations and recognizing the multifaceted challenges associated with maintaining air quality in underground metro systems, the aim of this paper was to evaluate the usefulness and effectiveness of utilizing rainwater for washing trains to abate particulate matter (PM) concentrations in underground rail systems. To achieve this aim, an ad hoc case study was considered: the Naples Metro Line 1 (Italy), which is characterized by 4.5 km in the ground level and 13.5 km underground. A measurement campaign was carried out during storms of strong intensity through PM measuring instruments placed on station platforms along the metro line. Precisely, the trains were washed by the rain in the initial ground level section, and then continued wet within the underground one. The results of this measurement campaign were compared with those of a comparable survey carried out during average clear weather conditions, and the results showed that the train washing produces a significant PM10 concentration reduction of up to about 60% in the underground environment. If confirmed in other experimental settings, these results could lay the groundwork for the introduction of structured washing system devices (e.g., periodically washing trains and/or tunnels) for the reduction of PM concentration in underground metro systems. The present study sought to contribute valuable insights towards sustainable and environmentally conscious approaches to addressing air quality concerns, particularly by harnessing the natural resource of rainwater during specific meteorological events.

show abstract

Characteristics of fine and ultrafine aerosols in the London underground

Cited by 8 publications

References 89 publications

SARS-CoV2 in public spaces in West London, UK during COVID-19 pandemic

SARS-CoV2 in public spaces in West London, UK during COVID-19 pandemic

Indoor air quality monitoring and source apportionment using low-cost sensors

Rain-Based Train Washing: A Sustainable Approach to Reduce PM Concentrations in Underground Environments

Contact Info

Product

Resources

About