Difference between revisions of "PM2.5 concentration from bus traffic in Helsinki in 2020"
m (→Formula) |
m (→Formula) |
||
| Line 23: | Line 23: | ||
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</sub> = (E<sub>c</sub>-E<sub>lrt</sub>)/f<sub>tr</sub>*f<sub>bus</sub> | + | '''E<sub>bus</sub> = (E<sub>c</sub>-E<sub>lrt</sub>)/f<sub>tr</sub>*f<sub>bus</sub>''' |
| − | fi = (Em<sub>i</sub> * wf<sub>i</sub>)/Sum(Em<sub>i</sub>*wf<sub>i</sub>) | + | '''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</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 </br> |
| − | + | '''E<sub>c</sub>''' is exposure to total exposure to combustion originating particles</br> | |
| − | '''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)</br> |
| − | + | '''f<sub>tr</sub>''' is the ratio of local road traffic exposure to local CoPM</br> | |
| − | '''E<sub>lrt</sub>''' is the concentration of combustion-based long-range transport (average exposure to long-range transported PM2.5) | + | '''f<sub>bus</sub>''' is the ratio of local bus-derived primary CoPM to all local road-traffic-derived CoPM</br> |
| − | + | '''Em<sub>i</sub>''' is the CoPM emissions in the Helsinki area (tn/year)</br> | |
| − | '''f<sub>tr</sub>''' is the ratio of local road traffic exposure to local CoPM | + | '''wf<sub>i</sub>''' is the relative weight factors to CoPM-emissions</br> |
| − | + | '''Index i''' denotes different CoPM sources in Helsinki</br> | |
| − | '''f<sub>bus</sub>''' is the ratio of local bus-derived primary CoPM to all local road-traffic-derived CoPM | + | '''wf''' is an estimate of the the impact of a unit emission on the average population exposure in the area</br> |
| − | |||
| − | '''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 | ||
| − | |||
| − | '''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 11:52, 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 </br> Ec is exposure to total exposure to combustion originating particles</br> Elrt is the concentration of combustion-based long-range transport (average exposure to long-range transported PM2.5)</br> ftr is the ratio of local road traffic exposure to local CoPM</br> fbus is the ratio of local bus-derived primary CoPM to all local road-traffic-derived CoPM</br> Emi is the CoPM emissions in the Helsinki area (tn/year)</br> wfi is the relative weight factors to CoPM-emissions</br> Index i denotes different CoPM sources in Helsinki</br> wf is an estimate of the the impact of a unit emission on the average population exposure in the area</br>
Unit
μg/m3
Result
Estimation of average bus-related primary PM2.5 in 2020 in Helsinki area
