DEKRA Study: Street Cleaning Reduces Fine Dust Pollution

Intensive street cleaning can reduce the development of fine particulates on traffic-heavy thoroughfares in larger cities. This is the result of a five-week study carried out in Stuttgart in March and April 2017.

Intensive road cleaning reduces the amount of fine dust generated. Photo: DEKRA

In order to be certain, more measurements will need to be taken and over longer periods. This was the message that DEKRA SE Chief Executive Clemens Klinke had for the city council committee at their session on 11. July in Stuttgart.

“It was clear that cleaning had a pronounced positive effect on the levels of coarse dust,” announced Klinke. “In order to gain conclusive evidence for the effects of street cleaning on fine dust levels, we recommend that the study is carried out again over a longer period of time.” DEKRA’s team of experts plan to acquire quantifiable results this coming winter, from November to February, for example. The associated cold temperatures and low wind speeds are expected to result in high fine dust concentrations – in absolute terms.

27 Nights of Cleaning at the Neckartor

In the trial, which ran from 1. March to 6. April, the roads around the heavily congested Neckartor were subject to 40 intensive cleaning operations across 27 nights. High-pressure washers and industrial vacuums, as well as the mechanical cleaning of the sidewalks were amongst the instruments and measures used. Taking part in the trial were the municipally-run AWS (Stuttgart Waste Management), Faun Umwelttechnik (Faun Environmental Technology) and Kärcher with 13 deployments respectively, as well as street cleaners from Reuther Straßenreinigung, who were dispatched on 14 occasions. The State Institute for the Environment, Measurements and Conservation in Baden-Württemberg (LUBW) also supported in analysis of the data.

Measurements Paint a Positive Picture

According to the most recent investigations carried out by the LUBW, only five per cent of local fine dust pollutants originate from exhaust gases in the vicinity, whereas 32 per cent are generated by the products of tires and brake abrasion, and their resuspension in the air. The goal of this cleaning exercise was to discover whether it is possible to remove coarser particles before further traffic degrades and pulverizes them into fine dust. Analysis of the values recorded for dustfall – indicative of coarser particles –  clearly showed positive results, as expected by the experts.