The summary report of the four-year REDUST project “Best practices in winter maintenance to reduce respirable street dust” has been published. The report presents the best practices in winter- and spring maintenance in the key segments of REDUST research. Also the effect of winter tyre properties on the street dust accumulation is touched, but the main focus is on street maintenance. In Helsinki Centre a major improvement has happened in the street dust situation during last ten years. The number of very dusty days caused by spring time street dust has decreased significantly, and the positive development continued during REDUST project. Accurate source analysis of the factors affecting street dust changes is not available for now, but improved maintenance actions is believed to have been an important factor behind the improvement in street dust situation.
Based on REDUST research and changes in the Helsinki Centre maintenance strategy and operational models especially dust binding seems to have high potential impact to street dust emissions. In Helsinki Centre dust binding has been performed more consistently and with faster reaction time (and also pre-emptively) during recent years. The result is seen in number of worse spring time street dust days, which have decreased significantly. Also street cleaning methods which apply high pressure water sprays, like the modern street scrubber and combination of suction sweeper and a washing lorry (combination cleaning), seem to reduce respirable particle emissions. Other factors which have also played a role in the improved street dust situation in Helsinki are use of wet sieved traction sanding material, reduction in speed limits and improved properties of the studded tyres following tightened regulation.
Despite the positive results it is very important that street dust control is focused on also in the coming years in the Helsinki metropolitan area. In future weather conditions may cause more difficult setting for street dust emissions, and the amount of respirable particle “exceedance days” may increase also in Helsinki. The results of REDUST project and the development of respirable particle emissions strongly suggest that improvements in street maintenance operation models and resources can have positive impact on street dust and the healthiness and comfortability of the surroundings of urban areas.
The REDUST Best practices -report is available through this link. The report has been composed mainly based on the earlier publications of REDUST project to summarize the key results and recommendations. More detailed information about the results and research methods of REDUST are available in the final and intermediary reports of Actions 1-4, available at the results section of this website.