1. DAPPLE Science Meeting 30 th November 2004 Department of Environmental Science & Technology Imperial College London, UK EXPOSURE ASSESSMENT S Kaur, M Nieuwenhuijsen, R Colvile

2. DAPPLE Science Meeting 30 th November 2004 Aims & Objectives Characterise and evaluate human exposure levels at and around a street canyon intersection to CO and fine particulate matter Assess variations in exposure between and within i) modes of transport, ii) routes and iii) timings Examine the relationship between human exposure to PM2.5 and CO at and around a street canyon intersection in relation to fixed site monitored concentrations Identify and quantify the main determinants of human exposure at and around a street canyon intersection Consider the policy implications arising from the research

3. DAPPLE Science Meeting 30 th November 2004 2003 Field Measurements

4. DAPPLE Science Meeting 30 th November 2004 Results: Data Capture 481 samples collected, 394 acceptable samples Overall Exposure to PollutantNAMA SDMin.Max. PM 2.5 (µg/m 3 )19733.614.55.377.5 Ultrafine Particle Counts (pt/cm 3 )86881013129136474178601 CO (ppm)1111.00.70.02.9

5. DAPPLE Science Meeting 30 th November 2004 Results: Timings PM 2.5 (µg/m) Ultrafine Particle Counts (pt/cm 3 ) CO (ppm) Timing 123123123 (8.30am)(12.00pm)(3.15pm)(8.30am)(12.00pm)(3.15pm)(8.30am)(12.00pm)(3.15pm) N616361312827373836 AM34.628.835.610627079188764831.50.70.8 ASD14.112.314.83407525487238180.70.5 Min.12.56.05.35253036679364740.20.0 Max.66.555.977.51786011289791273262.92.01.8

6. DAPPLE Science Meeting 30 th November 2004 Results: Modes of Transport

7. DAPPLE Science Meeting 30 th November 2004 Results: Routes NAMA SDMin.Max. PM 2.5 (µg/m 3 ) Marylebone Road Circuit10035.314.06.077.5 Gloucester Place & Backstreets 9731.814.75.371.8 Ultrafine Particle Count (pt/cm 3 ) Marylebone Road Circuit481011422918647300178601 Gloucester Place & Backstreets 38716282584436474158685 Carbon Monoxide (ppm) Marylebone Road Circuit611.30.60.42.9 Gloucester Place & Backstreets 500.60.50.02.0

8. DAPPLE Science Meeting 30 th November 2004 Correlations between Pollutants

9. DAPPLE Science Meeting 30 th November 2004 Ambient Monitoring

10. DAPPLE Science Meeting 30 th November 2004 Results: Other

11. DAPPLE Science Meeting 30 th November 2004 Data Analysed/Available (2003)

12. DAPPLE Science Meeting 30 th November 2004 Aims & Objectives Characterise and evaluate human exposure levels at and around a street canyon intersection to CO and fine particulate matter ✔ Assess variations in exposure between and within i) modes of transport, ii) routes and iii) timings ✔ Examine the relationship between human exposure to PM2.5 and CO at and around a street canyon intersection in relation to fixed site monitored concentrations ✔ Identify and quantify the main determinants of human exposure at and around a street canyon intersection Consider the policy implications arising from the research

13. DAPPLE Science Meeting 30 th November 2004 2004 Field Measurements

14. DAPPLE Science Meeting 30 th November 2004 2004 Field Data Status

15. DAPPLE Science Meeting 30 th November 2004 Analysis of Determinants of Exp. Identify and quantify the determinants of exposure Regression: the model assumes personal exposure is a function of independent variables (e.g. wind speed, wind direction, traffic density…etc) with a normally distributed random error Dependent on meteorological and traffic data availability Start with 2003 data

16. DAPPLE Science Meeting 30 th November 2004 Timeline Nov 2004 – Descriptive work for 2003 data complete Dec 2004 – Start data collection for regression analysis from other groups Jan 2005 – Descriptive work for 2004 data complete Mar/Apr ? 2005 – Basic analysis of determinants of exposure for 2003 data complete ????? Detailed analysis of determinants for 2003 data ????? Analysis of determinants for 2004 data

17. DAPPLE Science Meeting 30 th November 2004 Collaborators Health & Safety Laboratory, Sheffield (2003 & 2004) – exposure visualisation UCL – testing GPS and CO sensors NERI – requested fieldwork completed, awaiting funding

18. DAPPLE Science Meeting 30 th November 2004 Bus Measurements Top graph: example of timeseries ultrafine particle count at a bus stop (westbound, downstream of DAPPLE site on number 18 route) including peaks associated with arrival and departure of buses Lower graph: average timeseries ultrafine particle count measured on multiple journeys between Edgware Road and Regents Park stations on number 18 route, including the section through the DAPPLE site. Use of data to model exposure: 1)Combine concentration at bus stop with total waiting time and number of people waiting 2)Combine concentration on bus with journey time and bus occupancy 3)Note that most people experience the more polluted, delayed journeys! Clean buses have nobody on them!