Graham Howlett, general manager at Bucher Municipal UK, discusses an unexpected way of improving local air quality.
As air pollution continues to be a considerable environmental challenge and public health concern in the UK, there is a growing need for effective measures to reduce the levels of harmful particulate matter.
According to the World Health Organization, air pollution is responsible for an estimated seven million premature deaths each year worldwide.
Road transport is a leading contributor to air pollution, with vehicles emitting harmful pollutants such as nitrogen oxides (NOx), harmful particulate matter (PM) such as PM2.5 and PM10, and carbon monoxide (CO), which can cause respiratory and cardiovascular problems.
To tackle this issue, many cities and towns in the UK have implemented measures such as low emission zones and congestion charges.
However, a simple, low-tech solution that can complement these measures is often overlooked: road sweeping.
Road sweeping is an effective way to remove dirt, dust, and debris from roads, and pavements, as well as help prevent the build-up of harmful particulate matter especially in high traffic areas. It can also reduce the amount of dust that enters buildings, improving indoor air quality.
A Bucher road sweeper uses a fine mist of atomised water to bond with the dust particles, adding weight and ensuring they fall to the ground. These are then swept up using a vacuum system and, as the airflow reduces in the main body of the sweeper, they are deposited into the hopper with the other detritus.
Once these fine particles of dust have been collected they form part of the normal detritus in the back of the hopper and are deposited in local waste centres, or on council yards for safe removal.
Many of the road sweepers come with water recirculation as standard, meaning they reduce clean water usage by filtering and reusing ‘grey’ water to enhance dust suppression.
This ensures minimal dust is put back into the external environment and the sweepers have a net positive impact on air quality, as proven through the EUnited PM2.5 and PM10 certifications.
A study conducted in London found that regular road sweeping can lead to a 10% decrease in PM10 levels and a 16% decrease in PM2.5 levels observed in some areas.
The European Commission found that road dust accounts for up to 10% of total PM emissions in urban areas. Further studies have shown that these airborne particles from traffic and other sources can contribute to a range of health problems, including respiratory and cardiovascular diseases.
Similarly, the Environmental Research Group at King’s College London found that road sweeping had a significant impact on PM10 and PM2.5 concentrations, finding road sweeping reduced PM10 concentrations by up to 33% and PM2.5 concentrations by up to 29%.
Road surfaces accumulate other pollutants such as nitrogen dioxide (NO2) and volatile organic compounds (VOCs).
A study conducted by the University of Birmingham looked at the impact of road sweeping on NO2 concentrations in the city of Birmingham and found that it could reduce NO2 concentrations by up to 10%, and black carbon (a major contributor to climate change and a potent air pollutant that causes respiratory problems) concentrations by up to 33%.
In addition, sweeping removes oil and other hydrocarbons that are present on the road surface, as well as reducing the amount of heavy metals such as lead, cadmium, and zinc on the road surface by up to 85% (MGBA, 2019).
The benefits of road sweeping on air quality are not just limited to urban areas.
When road dust is left to build, it can wash into stormwater drains and eventually into rivers and streams. A study by the National Trust found that road sweeping helps reduce the amount of nitrogen and phosphorus that enters rivers and streams improving water quality. These pollutants lead to algae blooms, which harm fish and other aquatic life.
Regular road sweeping is a simple yet effective way to improve air quality in the UK. By removing dirt, dust, and debris from our streets, we can reduce the amount of harmful particulate matter in the air and improve the health of local residents.
With the continued focus on reducing air pollution, it is important to explore all possible solutions, and road sweeping is certainly one worth considering.
