Changes in Ultrafine Particle Concentrations near a Major Airport Following Reduced Transportation Activity during the COVID-19 Pandemic

Abstract

Mobility reductions following the COVID-19 pandemic in the United States were higher, and sustained longer, for aviation than ground transportation activity. We evaluate changes in ultrafine particle (UFP, Dp < 100 nm, a marker of fuel-combustion emissions) concentrations at a site near Logan Airport (Boston, Massachusetts) in relation to mobility reductions. Several years of particle number concentration (PNC) data prepandemic [1/2017–9/2018] and during the state-of-emergency (SOE) phase of the pandemic [4/2020–6/2021] were analyzed to assess the emissions reduction impact on PNC, controlling for season and wind direction. Mean PNC was 48% lower during the first three months of the SOE than prepandemic, consistent with 74% lower flight activity and 39% (local)–51% (highway) lower traffic volume. Traffic volume and mean PNC for all wind directions returned to prepandemic levels by 6/2021; however, when the site was downwind from Logan Airport, PNC remained lower than prepandemic levels (by 23%), consistent with lower-than-normal flight activity (44% below prepandemic levels). Our study shows the effect of pandemic-related mobility changes on PNC in a near-airport community, and it distinguishes aviation-related and ground transportation source contributions.

Characterization of size-fractionated carbonaceous particles in the small to nano-size range in Batam city, Indonesia

“…Fine particles, <2.5 μm accounted for around 59% of TSP. Considering that Batam Island is larger than Padang city and Muaro Jambi regency, taking into account the population and number of vehicle users, one of the reasons for the lower fraction of fine particles compared to other cities might be due to the covid-19 pandemic [ [39] , [40] , [41] ]. During the sampling period, Batam island was in lockdown and the government permitted only limited outdoor activities.…”

Uncertainties in mitigating aviation non-CO2 emissions for climate and air quality using hydrocarbon fuels

“…Ultra-ne particles (<100 nm in aerodynamic diameter) are of particular concern, since these maybe harmful to health (see Bendtsen et al, 2021 for a review), 149 and many measurement campaigns have conrmed their presence around airports. [150][151][152][153] Specic studies of health effects of aircra emissions (as opposed to UFPs in general) are rather few but indicate that there may be demonstrable effects on bronchial cells. 154 Emissions of organic compounds (which may contribute to secondary ultrane particles) remain poorly characterized, particularly in terms of speciation 63 but recent more complex measurements have made important steps to identify such species.…”