Difference between revisions of "PM2.5 concentration from bus traffic in Helsinki in 2020"
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'''f<sub>tr</sub>''' is the ratio of local road traffic exposure to local CoPM (no units)<br> | '''f<sub>tr</sub>''' is the ratio of local road traffic exposure to local CoPM (no units)<br> | ||
'''f<sub>bus</sub>''' is the ratio of local bus-derived primary CoPM to all local road-traffic-derived CoPM (no units)<br> | '''f<sub>bus</sub>''' is the ratio of local bus-derived primary CoPM to all local road-traffic-derived CoPM (no units)<br> | ||
| − | '''Em<sub>i</sub>''' is the CoPM emissions in the Helsinki area ( | + | '''Em<sub>i</sub>''' is the CoPM emissions in the Helsinki area (%)<br> |
'''wf<sub>i</sub>''' is the relative weight factors to CoPM-emissions (no units)<br> | '''wf<sub>i</sub>''' is the relative weight factors to CoPM-emissions (no units)<br> | ||
'''wf''' is an estimate of the the impact of a unit emission on the average population exposure in the area (no units)<br> | '''wf''' is an estimate of the the impact of a unit emission on the average population exposure in the area (no units)<br> | ||
'''Index i''' denotes different CoPM sources in Helsinki<br> | '''Index i''' denotes different CoPM sources in Helsinki<br> | ||
| + | |||
=== Unit === | === Unit === | ||
Revision as of 12:14, 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 (μg/m3)
Ec is total exposure to combustion originating particles (μg/m3)
Elrt is the concentration of combustion-based long-range transport (average exposure to long-range transported PM2.5)(μg/m3)
ftr is the ratio of local road traffic exposure to local CoPM (no units)
fbus is the ratio of local bus-derived primary CoPM to all local road-traffic-derived CoPM (no units)
Emi is the CoPM emissions in the Helsinki area (%)
wfi is the relative weight factors to CoPM-emissions (no units)
wf is an estimate of the the impact of a unit emission on the average population exposure in the area (no units)
Index i denotes different CoPM sources in Helsinki
Unit
μg/m3
Result
Estimation of average bus-related primary PM2.5 in 2020 in Helsinki area
