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 | ||
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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 | ||
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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) | ||
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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 | ||
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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 | ||
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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) | ||
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wf<sub>i</sub> is the relative weight factors to CoPM-emissions | wf<sub>i</sub> is the relative weight factors to CoPM-emissions | ||
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Index i denotes different CoPM sources in Helsinki | Index i denotes different CoPM sources in Helsinki | ||
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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 | ||
Revision as of 11:35, 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
