“Correction of PM10 measurements: French approach” O. Le Bihan (LCSQA/INERIS) and J. Colosio (ADEME).

1. 11th EIONET Workshop on Air Quality Assessment and Management, La Rochelle, France, 26-27 October, 2006. “Correction of PM10 measurements: French approach” O. Le Bihan (LCSQA/INERIS) and J. Colosio (ADEME).

2. Correction of PM10 monitoring • The French air quality monitoring system : • 37 AQ monitoring networks • about 400 automatic measuring stations • Each AQ monitoring network is managed by a non-profit-making association in which are involved representatives from : • the French state, • the local authorities, • Industries, • environmental organisations.

3. Correction of PM10 monitoring • The correction of PM10 measurements has been a collective decision • Correction using a constant factor (such as 1.3): • No relevant (the relation to the reference method is not stable in time and space) • Consequences : • Annual average values are overestimated, • Creation of wrong LV exceedances, • Results could not be in accordance with the data quality objectives • France has decided to look for an instrumental solution

4. Correction of PM10 monitoring • The instrumental solution : to carry out special “modules” taking into account the semi-volatile particulate compounds [FDMS (TEOM) or RST (beta gauge)] • Official recognition for these methods: • Demonstration of equivalence scheme: 2 campaigns (Paris2005 / Marseille2006) • Positive results on TEOM-FDMS PM10 and PM2.5; Beta Jauge MP101 Env. SA with RST (24h hours sampling) • EU Workshop, 2007

5. Example: 2005 « demonstration of equivalence » campaign in ParisFDMS and SRM correlation for PM2.5

6. Correction of PM10 monitoring • Measuring devices will be fitted gradually, but not every device • We have to correct the results provided by measuring instruments without module

7. Correction of PM10 monitoring • Assumption: the monitoring of volatile compounds does not have only a “local” signification • Method planned for correction (first step): • We will set up « reference » stations with 2 measuring devices : one without module and the other with module (e.g. TEOM 50°C and TEOM_FDMS) • On each reference station, calculation of the difference between the 2 results (e.g. TEOM_FDMS - TEOM50°C ) • This difference will be added to the results provided by the devices without module located near the reference station

8. Correction of PM10 monitoring • Future “reference” stations

9. Correction of PM10 monitoring • Results will be corrected taking into account the following issues : • Data registered at the local level and at the national level must be the same • Implementation of correction by the 1st of January 2007 • Correction must not introduce inconsistency between stations fitted with modules (no correction) and the others without module • Good quality of the correction

10. Correction of PM10 monitoring • This method will be improved (second step): • The number of reference stations will be increased over several years until the optimal situation • Experience will allow to improve quality of correction

11. 11th EIONET Workshop on Air Quality Assessment and Management, La Rochelle, France, 26-27 October, 2006 Correction of PM10 measurements: implementation Département Surveillance de la Qualité de l’Air Joëlle COLOSIO

12. Technical organisation 37 local networks 37 local databases 2 softwares local station (400 stations for PM 10) Automatic devices TEOM : 320 Beta Gauge : 80 PM2.5 : 80 stations TEOM National database

13. Delay : 01 01 2007 • Implement the technical solution : • Installation of References stations : 1 minimum by network = 45 • Link the PM sites to the most appropriate Reference Station • Implementation of the correction module in 37 networks database • Implementation in the national Database in ADEME Total cost : 300 k€

14. Reference station [TEOM] ] Correction factor calculated for every 1/4H data with the 16 1/4h previous data [TEOM FDMS] other station National database : Teom Teom FDMS Ajusted Teom [TEOM] [TEOM] [TEOM] [TEOM] [TEOM] [TEOM] [TEOM] [TEOM] For other PM sites the correction is implemented for the corresponding 1/4h measurement in the software Just before the validation

15. Many thanks to... • The members of the French WG “particles” • AASQA : Airparif, Airmaraix, etc... • Ecomesure, Environnement SA • European partners : RIVM, VMM, ISSeP, JRC Ispra, LUA, CSIC, EMPA.