2023-03-27 バーミンガム大学
これらの問題に対処するためには、電気自動車の普及を高める必要があるとともに、ディーゼル車の排出物を減らすための追加措置が必要とされている。WHOのガイドラインによると、1立方cm当たり1万個を超える極微小粒子の濃度は「高い」とされるが、今回の調査では、このレベルを2倍超える値が観測されていた。
＜関係情報＞
- https://www.birmingham.ac.uk/news/2023/vehicle-exhaust-filters-do-not-remove-ultrafine-pollution-new-study
- https://www.sciencedirect.com/science/article/pii/S0160412023001617
ディーゼルパーティクルフィルターが道路交通の超微粒子排出量に与える影響は限定的 Limited impact of diesel particle filters on road traffic emissions of ultrafine particles
Seny Damayanti, Roy M. Harrison, Francis Pope, David C.S. Beddows
Environment International Available online: 21 March 2023
DOI:https://doi.org/10.1016/j.envint.2023.107888
Highlights
- •Roadside measurements of particle size distributions from 2010 to 2021.
- •Diesel particle filters introduced from 2011 steadily reduce black carbon concentrations.
- •Nucleation mode particles are little changed and total ultrafine particles show a small decline in concentration.
- •Ultrafine particle concentrations remain in the “high” category as defined by WHO.
Abstract
Diesel engines are a major contributor to emissions of both Black Carbon (BC) and ultrafine particles. Analysis of data from the only roadside monitoring site in Europe with a continuous dataset for size-segregated particle number count (Marylebone Road, London) from 2010 to 2021 reveals that the growing number of vehicles fitted with a Diesel Oxidation Catalyst (DOC) and Diesel Particle Filter (DPF) has been very effective in controlling the emissions of solid particles and hence BC, but that there has been little change in the liquid mode (<30 nm) particles, and that concentrations of ultrafine particles (<100 nm) still well exceed the threshold for “high” concentrations (>104 cm−3 /24-hour mean) defined by WHO. BC declined by 81% between 2014 and 2021, but the ultrafine particle (<100 nm) count declined by only 26%. Consequently, in locations worldwide with heavy diesel traffic, concentrations of ultrafine particles are likely to remain “high” for the foreseeable future unless more effective abatement technologies are implemented.
