Abstract
Ultrafine particles (UFP; particulatematter
From late-March to mid-July 2020, UFP was repeatedly measured while walking or bicycling, capturing local COVID-19 closure (`Phase 0') and subsequent phased re-opening (`Phase 1', '2', '2.1' & '3'). A DiSCmini continuouslymeasured particle number concentration (PNC) in thewalker/bicyclist's breathing zone. PNCwhilewalking or bicycling was compared across phased re-openings, and the effect of ambient temperature, wind speed and direction was determined using regression models.
Approximately 40 repeated 20-minute walking and bicycling laps were made over 4 months during societal reopening phases related to the COVID-19 pandemic (late-March to mid-July 2020) in Copenhagen. Highest median PNC exposure of both walking ( 13,170 pt/cm(3), standard deviation (SD): 3560 pt/cm(3)) and bicycling (21,477 pt/cm(3), SD: 8964) was seen during societal closures (Phase 0) and decreased to 5367 pt/cm(3) (SD: 2949) and 8714 pt/cm(3) (SD: 4309) in Phase 3 of re-opening. These reductions in PNC were mainly explained by meteorological conditions, with most of the deviation explained by wind speed (14-22%) and temperature (10-13%). Highest PNC was observed along major roads and intersections.
In conclusion, we observed decreases in UFP exposure while walking and bicycling during societal re-opening phases related to the COVID-19 pandemic, due largely to meteorological factors (e.g., wind speed and temperature) and seasonal variations in UFP levels. (C) 2021 The Authors. Published by Elsevier B.V.
Original language | English |
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Article number | 148301 |
Journal | Science of the Total Environment |
Volume | 791 |
Number of pages | 9 |
ISSN | 0048-9697 |
DOIs | |
Publication status | Published - 2021 |
Keywords
- Air pollution
- Bicycling
- COVID-19
- Environmental exposure
- Ultrafine particles
- Walking
- AIR-POLLUTION EXPOSURES
- PARTICULATE MATTER
- PERSONAL EXPOSURE
- COMMUTER EXPOSURE
- CYCLIST EXPOSURE
- CARBON-MONOXIDE
- URBAN ROUTES
- BLACK CARBON
- TRANSPORT
- COUNTS