Road dust emissions from paved roads measured using different mobile systems.
Very few real-world measurements of road dust suspension
have been performed to date. This study compares
two different techniques (referred to as Sniffer and Emma)
to measure road dust emissions. The main differences
between the systems are the construction of the inlet,
different instruments for recording particulate matter
(PM) levels, and different loads on the wheel axes (the
weight of Sniffer was much higher than that of Emma).
Both systems showed substantial small-scale variations of
emission levels along the road, likely depending on-road
surface conditions. The variations observed correlated
quite well, and the discrepancies are likely a result of variations in dust load on the road surface perpendicular
to the driving direction that cause variations in the measurements
depending on slightly different paths driven
by the two vehicles. Both systems showed a substantial
influence on the emission levels depending on the type of
tire used. The summer tire showed much lower suspension
than the winter tires (one nonstudded and one studded).
However, the relative importance of the nonstudded
versus studded tire was rather different. For the ratio of
studded/nonstudded, Emma shows higher values on all
road sections compared with Sniffer. Both techniques
showed increased emission levels with increasing vehicle
speed. When the speed increased from 50 to 80 km hr1,
the relative concentrations increased by 30–170% depending
on the tire type and dust load. However, for road
sections that were very dirty, Sniffer showed a much
higher relative increase in the emission level with the
nonstudded tire. Sniffer’s absolute concentrations were
mostly higher than Emma’s. Possible reasons for the differences
are discussed in the paper. Both systems can be
used for studying relative road dust emissions and for
designing air quality management strategies.
PM10 emission från betongbeläggning.
Surface characteristics, copper release and toxicity of nano- and micron sized copper and copper(II)oxide particles, -A cross-disciplinary study
Copper oxide nanoparticles are highly toxic in vitro – a comparison between different nanoparticles
Factors affecting non-tailpipe aerosol particle emissions from paved roads: On-road measurements in Stockholm, Sweden
A large fraction of urban PM10 concentrations is due to non-exhaust traffic emissions. In this paper, a mobile measurement system has been used to quantify the relative importance of road particle emission and suspension of accumulated dust versus direct pavement wear, tire type (studded, friction, and summer), pavement type, and vehicle speed. Measurements were performed during May-September on selected roads with different pavements and traffic conditions in the Stockholm region. The highest particle mass concentrations were always observed behind the studded tire and the lowest were behind the summer tire; studded-to-summer ratios were 4.4-17.3 and studded-to-friction ratios were 2.0-6.4. This indicates that studded tires lead to higher emissions than friction and summer tires regardless to the asphalt type. By comparing with measurements in a road simulator, it could be estimated that the pavement wear due to the friction tires was 0.018-0.068 of the suspension of accumulated road dust. Likewise for studded tires road-wear was estimated to be 1.2-4.8 the suspension of accumulated dust. This indicates that wear due to friction tires is very small compared to the suspension of accumulated dust and that suspension due to studded tires may sometimes be as large as the wear of the road. But this will vary depending on, e.g. the amount of dust accumulated on the roads. An important dependence on vehicle speed was also observed. During May, the particle mass concentrations behind the studded tire at vehicle speed 100 km h(-1) were about 10 times higher than that at 20 km h(-1). The speed dependence was not so pronounced in September, which could be due to less accumulated dust on the roads. The particle number size distribution of the emissions due to road wear by studded tire was characterized by a clear increase in number concentrations of the coarse fraction of aerosol particles, with a geometric mean diameter between 3 and 5 mu m. The size distribution of the emissions due to the summer tire was very similar with smaller concentrations. An important limitation with the measurements presented is that they were made by using a van, which is bigger than regular cars and has bigger tires. Thus, road wear and dust suspension due to cars are expected to be different. (C) 2007 Elsevier Ltd. All rights reserved.