Difference between revisions of "PM2.5 concentration from bus traffic in Helsinki in 2020"
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<u>Where:</u> | <u>Where:</u> | ||
| − | E<sub>bus</sub> is average PM2.5 exposure to primary particles from local buses | + | '''E<sub>bus</sub>''' is average PM2.5 exposure to primary particles from local buses |
| − | E<sub>c</sub> is exposure to total exposure to combustion originating particles | + | '''E<sub>c</sub>''' is exposure to total exposure to combustion originating particles |
| − | E<sub>lrt</sub> is the concentration of combustion-based long-range transport (average exposure to long-range transported PM2.5) | + | '''E<sub>lrt</sub>''' is the concentration of combustion-based long-range transport (average exposure to long-range transported PM2.5) |
| − | f<sub>tr</sub> is the ratio of local road traffic exposure to local CoPM | + | '''f<sub>tr</sub>''' is the ratio of local road traffic exposure to local CoPM |
| − | f<sub>bus</sub> is the ratio of local bus-derived primary CoPM to all local road-traffic-derived CoPM | + | '''f<sub>bus</sub>''' is the ratio of local bus-derived primary CoPM to all local road-traffic-derived CoPM |
| − | Em<sub>i</sub> is the CoPM emissions in the Helsinki area (tn/year) | + | '''Em<sub>i</sub>''' is the CoPM emissions in the Helsinki area (tn/year) |
| − | wf<sub>i</sub> is the relative weight factors to CoPM-emissions | + | '''wf<sub>i</sub>''' is the relative weight factors to CoPM-emissions |
| − | Index i denotes different CoPM sources in Helsinki | + | '''Index i''' denotes different CoPM sources in Helsinki |
| − | wf is an estimate of the the impact of a unit emission on the average population exposure in the area | + | '''wf''' is an estimate of the the impact of a unit emission on the average population exposure in the area |
=== Unit === | === Unit === | ||
Revision as of 11:51, 21 February 2008
Scope
- Spatial limits: Helsinki metropolitan area
- Temporal limits: year 2020
- Type of pollutant: primary PM2.5
- Source of pollutant: bus traffic
Definition
Causality
List of parents:
Data
List of data files or sources:
- Database from EXPOLIS study (1996-1997) - individual measurements of total outdoor PM exposure
- Database from ULTRA study - fixed monitoring sites
Formula
Total PM2.5 exposure/concentration was used as the starting point for the calculations of PM2.5 due to bus traffic, subtracting the contributions from other sources.
Ebus = (Ec-Elrt)/ftr*fbus
fi = (Emi * wfi)/Sum(Emi*wfi)
Where:
Ebus is average PM2.5 exposure to primary particles from local buses
Ec is exposure to total exposure to combustion originating particles
Elrt is the concentration of combustion-based long-range transport (average exposure to long-range transported PM2.5)
ftr is the ratio of local road traffic exposure to local CoPM
fbus is the ratio of local bus-derived primary CoPM to all local road-traffic-derived CoPM
Emi is the CoPM emissions in the Helsinki area (tn/year)
wfi is the relative weight factors to CoPM-emissions
Index i denotes different CoPM sources in Helsinki
wf is an estimate of the the impact of a unit emission on the average population exposure in the area
Unit
μg/m3
Result
Estimation of average bus-related primary PM2.5 in 2020 in Helsinki area
