Difference between revisions of "PM2.5 concentration from bus traffic in Helsinki in 2020"

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m (→‎Formula: Added subscripts)
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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<sub>bus</bus> = (Ec-Elrt)/f(tr)*f(bus)
+
E<sub>bus</sub> = (E<sub>c</sub>-E<sub>lrt</sub>)/f<sub>tr</sub>*f<sub>bus</sub>
  
−
fi = (Emi * wfi)/Sum(Emi*wfi)
+
fi = (Em<sub>i</sub> * wf<sub>i</sub>)/Sum(Em<sub>i</sub>*wf<sub>i</sub>)
  
 
<u>Where:</u>
 
<u>Where:</u>
−
E<sub>bus</bus> 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
−
Ec is exposure to total exposure to combustion originating particles
+
E<sub>c</sub> 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)
+
E<sub>lrt</sub> 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<sub>tr</sub> 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
+
f<sub>bus</sub> is the ratio of local bus-derived primary CoPM to all local road-traffic-derived CoPM
−
fi is
+
Em<sub>i</sub> is the CoPM emissions in the Helsinki area (tn/year)
−
Emi is the CoPM emissions in the Helsinki area (tn/year)
+
wf<sub>i</sub> is the relative weight factors to CoPM-emissions
−
wfi 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

Revision as of 11:34, 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

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