City Scale Modeling of Ultrafine Particles in Urban Areas with Special Focus on Passenger Ferryboat Emission Impact.

Marvin Lauenburg,Volker Matthias,Markus Quante,Martin Ramacher,Matthias Karl

doi:10.3390/toxics10010003

Marvin Lauenburg, Volker Matthias + Show 3 more

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https://doi.org/10.3390/toxics10010003

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Abstract

Air pollution by aerosol particles is mainly monitored as mass concentrations of particulate matter, such as PM10 and PM2.5. However, mass-based measurements are hardly representative for ultrafine particles (UFP), which can only be monitored adequately by particle number (PN) concentrations and are considered particularly harmful to human health. This study examines the dispersion of UFP in Hamburg city center and, in particular, the impact of passenger ferryboats by modeling PN concentrations and compares concentrations to measured values. To this end, emissions inventories and emission size spectra for different emission sectors influencing concentrations in the city center were created, explicitly considering passenger ferryboat traffic as an additional emission source. The city-scale chemical transport model EPISODE-CityChem is applied for the first time to simulate PN concentrations and additionally, observations of total particle number counts are taken at four different sampling sites in the city. Modeled UFP concentrations are in the range of 1.5–3 × 104 cm−3 at ferryboat piers and at the road traffic locations with particle sizes predominantly below 50 nm. Urban background concentrations are at 0.4–1.2 × 104 cm−3 with a predominant particle size in the range 50–100 nm. Ferryboat traffic is a significant source of emissions near the shore along the regular ferry routes. Modeled concentrations show slight differences to measured data, but the model is capable of reproducing the observed spatial variation of UFP concentrations. UFP show strong variations in both space and time, with day-to-day variations mainly controlled by differences in air temperature, wind speed and wind direction. Further model simulations should focus on longer periods of time to better understand the influence of meteorological conditions on UFP dynamics.

Highlights

Introduction published maps and institutional affilAir pollution represents the largest environment-related health risk in Europe, with4.0 × 105 premature deaths annually [1]
The city-scale chemical transport model EPISODE-CityChem [39,40] is applied to model ultrafine particles (UFP) concentrations in Hamburg city center on five days in February 2021
UFP are considered to be of particular harm for human health, air quality monitoring mainly takes place in terms of mass-based concentration units, which are hardly representative for UFP

Summary

Introduction

Introduction published maps and institutional affilAir pollution represents the largest environment-related health risk in Europe, with4.0 × 105 premature deaths annually [1]. Air pollution represents the largest environment-related health risk in Europe, with. Aerosol particles are considered the air pollutant most relevant to health [2,3]. In Germany, particulate matter concentrations have been constantly monitored since 1995 by measuring the particulate mass per cubic meter of outdoor air, and exceedances are recorded in accordance with EU-wide legislation. Ultrafine particles (UFP; particles with mobility diameter less than 100 nm) are not adequately represented in existing mass-based particle monitoring [6,7,8]. The ultrafine spectrum comprises 80–90% of the particle number concentration [9,10], but only a small fraction of the total particle mass.

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