Difference between revisions of "PM2.5 concentration from bus traffic in Helsinki in 2020"
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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. | 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. | ||
| − | E | + | E<sub>bus</bus> = (Ec-Elrt)/f(tr)*f(bus) |
fi = (Emi * wfi)/Sum(Emi*wfi) | fi = (Emi * wfi)/Sum(Emi*wfi) | ||
| + | |||
| + | <u>Where:</u> | ||
| + | E<sub>bus</bus> 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) | ||
| + | f(tr) is the ratio of local road traffic exposure to local CoPM | ||
| + | f(bus) is the ratio of local bus-derived primary CoPM to all local road-traffic-derived CoPM | ||
| + | fi is | ||
| + | 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 === | === Unit === | ||
Revision as of 11:28, 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</bus> = (Ec-Elrt)/f(tr)*f(bus)
fi = (Emi * wfi)/Sum(Emi*wfi)
Where: Ebus</bus> 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) f(tr) is the ratio of local road traffic exposure to local CoPM f(bus) is the ratio of local bus-derived primary CoPM to all local road-traffic-derived CoPM fi is 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
