PM 10 and PM 2.5 MASS CLOSURE in the LAZIO region (CENTRAL ITALY)

1. EMEP TFMM 7th MEETING – HELSINKI, 10th-12th May 2006 PM10 and PM2.5 MASS CLOSURE in the LAZIO region (CENTRAL ITALY) Cinzia PERRINO C.N.R. Institute of Atmospheric Pollution Montelibretti (Rome) A study funded by the Lazio region

2. C. Perrino C.N.R. Istituto sull’Inquinamento Atmosferico – Montelibretti (Roma) OUR STARTING POINT ROME – TRAFFIC STATION : 194 PM10 EXCEEDANCES IN 2004

3. C. Perrino C.N.R. Istituto sull’Inquinamento Atmosferico – Montelibretti (Roma) WHICH ARE THE DRIVING FACTORS DETERMINING THE TIME PATTERN OF ATMOSPHERIC POLLUTANTS? WHICH CONDITIONS LEAD TO EXCEEDANCES? WHICH COMPOUNDS ARE RESPONSABLE FOR THE INCREASE IN PM CONCENTRATION? WHICH SOURCES ARE RESPONSABLE FOR THE DIRECT OR INDIRECT PRODUCTION OF THESE COMPOUNDS?

4. MONTELIBRETTI semi-rural station VITERBO urban station FONTECHIARI regional background station ROMA VILLA ADA urban background station ROMA MONTEZEMOLO traffic station LATINA urban station C. Perrino C.N.R. Istituto sull’Inquinamento Atmosferico – Montelibretti (Roma) “Fine Dust” 2004 - 2005 A research project funded by the Lazio Region

5. Study of the chemical composition of atmospheric particles • apportionment of particle sources • discrimination between natural and anthropogenic events October 2004 – July 2005 (daily sampling – analysis of the 140 most interesting days) Six stations: 1 regional background, 1 urban background, 1 peri-urban, three urban stations (Roma, Latina Viterbo) Two size fractions: PM10, PM2.5 C. PERRINO - C.N.R. Institute of Atmospheric Pollution

6. C.N.R. Institute of Atmospheric Pollution – Rome (ITALY) • 3-step procedure: • Mixing properties of the lower atmosphere • Size distribution of particulate matter • Chemical composition of particles Natural radioactivity monitoring Optical particle counter Analysis of metals, ions, carbon compounds

7. atmospheric concentration of pollutants emission (and physico-chemical trasnformation) mixing properties of the lower atmosphere C.N.R. Institute of Atmospheric Pollution – Rome (ITALY) Having information about the air volume available for pollution dispersion we could uncouple pollutants variations due to changes in the emission rate from those due to changes in the dilution properties of the atmosphere

8. STEP 1: Mixing properties of the lower atmosphere 222RADON SHORT-LIVED RADON PROGENY 238URANIUM DECAY CHAIN C.N.R. Institute of Atmospheric Pollution – Rome (ITALY)

9. STEP 1: Mixing properties of the lower atmosphere Convective mixing of the lower atmosphere: Radon dilutes into the whole mixing layer Weak mixing of the lower atmosphere: Radon is trapped in the lower layer and its air concentration increases

10. STEP 1: Mixing properties of the lower atmosphere ATMOSFERIC STABILITY MONITOR the instrument collects atmospheric particles and determines the natural radioactivity due to Radon progeny (1-h average). good index of the dilution properties of the lower atmosphere identification of stability periods and advection periods

11. C.N.R. Institute of Atmospheric Pollution – Rome (ITALY) During warm months natural radioactivity shows a well-defined and modulated temporal pattern (all days are similar: nocturnal stability and convective mixing during the day) During cold months high-pressure periods are sporadic and advection often occurs. Diurnal mixing is weak and of limited duration.

12. ROME - Traffic station JUNE – JULY 2003 ROME - Traffic station DECEMBER 2003 C.N.R. Institute of Atmospheric Pollution – Rome (ITALY) NATURAL RADIOACTIVITY JUNE – JULY 2003 NATURAL RADIOACTIVITY DECEMBER 2003

13. C.N.R. Institute of Atmospheric Pollution – Rome (ITALY) STEP 1: Mixing properties of the lower atmosphere

14. STEP 1: Mixing properties of the lower atmosphere C.N.R. Institute of Atmospheric Pollution – Rome (ITALY)

15. STEP 1: Mixing properties of the lower atmosphere C. Perrino C.N.R. Istituto sull’Inquinamento Atmosferico – Montelibretti (Roma) Starting from natural raadioactivity values we can develop Atmospheric Stability Indexes… EXPERIMENTAL FORECASTED … for each day, they give the probability, from the meteorological point of view, for the occurrence of an atmospheric pollution event

16. C.N.R. Institute of Atmospheric Pollution – Rome (ITALY) The episode of December 27th 2003 in Rome: traffic or meteorology?

17. C.N.R. Institute of Atmospheric Pollution – Rome (ITALY)

18. C.N.R. Institute of Atmospheric Pollution – Rome (ITALY)

19. C. Perrino C.N.R. Istituto sull’Inquinamento Atmosferico – Montelibretti (Roma) FIRST REMARK The mixing properties of the lower atmosphere are a key factor in determining PM concentration level and its time variations

20. C.N.R. Institute of Atmospheric Pollution – Rome (ITALY) • 3-step procedure: • Mixing properties of the lower atmosphere • Size distribution of particulate matter • Chemical composition of particles Natural radioactivity monitoring Optical particle counter Analysis of metals, ions, carbon compounds

21. STEP 2:Size distribution of particulate matter C.N.R. Institute of Atmospheric Pollution – Rome (ITALY) Optical particle counter in six size ranges: 0.3 – 0.5 m; 0,5 – 1,0 m; 1,0 – 1,5 m; 1,5 – 2,0 m 2 – 5 m; 5 – 10 m

22. STEP 2:Size distribution of particulate matter C.N.R. Institute of Atmospheric Pollution – Rome (ITALY) Evaluation of the ratio between the number of particles in the coarse ( > 1,5 m) and the fine (0,3 – 0,5 m) ranges

23. STEP 2:Size distribution of particulate matter IDENTIFICATION OF NATURALEVENTS C.N.R. Institute of Atmospheric Pollution – Rome (ITALY) Daily average ratio between the number of particles in the coarse ( > 1,5 m) and the fine (0,3 – 0,5 m) ranges

24. FASE 2: DISTRIBUZIONE DIMENSIONALE DELLE PARTICELLE C. Perrino C.N.R. Istituto sull’Inquinamento Atmosferico – Montelibretti (Roma) In the case of natural events (e.g. Saharan dust intrusions) the Atmospheric Stability Indexes are much lower than the real concentration of PM

25. C.N.R. Institute of Atmospheric Pollution – Rome (ITALY) • 3-step procedure: • Mixing properties of the lower atmosphere • Size distribution of particulate matter • Chemical composition of particles Natural radioactivity monitoring Optical particle counter Analysis of metals, ions, carbon compounds

26. STEP 3: Chemical composition of particles Ion chromatography (IC) Termo-optical analyser X-ray fluorescence (ED-XRF) Sampling by diffusion lines and IC analysis C.N.R. Institute of Atmospheric Pollution – Rome (ITALY) Chemical characterisation: 1.  Anions and cations (NO3-, SO4=, Cl-, Na+, Ca++, Mg++, K+, NH4+)  2. Elemental carbon and organic carbon compounds (EC, OC) 3.  Crustal metals (major components) (Si,Al, Fe, Ca, K) 4. Inorganic volatile components (ammnium chloride and nitrate)

27. STEP 3: Chemical composition of particles Quartz filter Teflon filter Crustal metals C.N.R. Institute of Atmospheric Pollution – Rome (ITALY) PM10 PM2.5 Organic carbon Elemental carbon Termo-optical analyser ED-XRF Extraction plus DIFFUSION LINES at ML station Trace metals ICP Ion chromatography Univ.of Rome “La Sapienza” Chemistry Department Anions and cations

28. C.N.R. Institute of Atmospheric Pollution – Rome (ITALY) MASS CONCENTRATION OF PM10 IN MONTELIBRETTI (ROME) MEASURED BY THE DUST MONITOR (blue) AND RECONSTRUCTED BY THE CHEMICAL ANALYSES (red)

29. C.N.R. Institute of Atmospheric Pollution – Rome (ITALY) MASS CONCENTRATION OF PM2.5 IN MONTELIBRETTI (ROME) MEASURED BY THE DUST MONITOR (blue) AND RECONSTRUCTED BY THE CHEMICAL ANALYSES (red)

30. STEP 3: Chemical composition of particles C.N.R. Institute of Atmospheric Pollution – Rome (ITALY) 10-15% of the ammonium nitrate is lost by the 20°C monitor and about 80% is lost by the 45°C monitor

31. STEP 3: Chemical composition of particles a = 1.6 ÷ 2.1 OM = a OC C.N.R. Institute of Atmospheric Pollution – Rome (ITALY) 4 main sources [sea-spray aerosol] = (Na+ + Cl-) * 1.176 [SO4= Mg Ca K] [crustal] = (1.89 Al + 2.14 Si + 1.4 Ca + 1.2 K + 1.36 Fe) * 1.12 [Mg Na Ti] [primary anthropogenic compounds] = EC * 2 [OM] [secondary compounds] = NH4+ + SO4= + NO3- + (OM – EC)

32. STEP 3: Chemical composition of particles C.N.R. Institute of Atmospheric Pollution – Rome (ITALY)

33. STEP 3: Chemical composition of particles C.N.R. Institute of Atmospheric Pollution – Rome (ITALY)

34. STEP 3: Chemical composition of particles C.N.R. Institute of Atmospheric Pollution – Rome (ITALY) • Sea-spray events: • NaCl concentration increases from 1-2% to 20-40% • the coarse/fine ratio increases • they occur in advection conditions (generally clean air masses) • PM10 concentretion is low; the increase due to sea-salt is generally < 10 ug/m3 • generally they do no cause exceedances • they have low impact on PM2.5 concentration

35. STEP 3: Chemical composition of particles C.N.R. Institute of Atmospheric Pollution – Rome (ITALY)

36. STEP 3: Chemical composition of particles C.N.R. Institute of Atmospheric Pollution – Rome (ITALY) • Saharan dust events: • crustal matter concentration increases from 10-20% to over 50% • the coarse/fine ratio increases • they begin in advection conditions (but re-suspension may increase the time duration of the episode) • PM10 concentretion can be very high (up to more than 100 ug/m3) • they often cause exceedances • they also generally causean increase of PM2.5 concentration

37. STEP 3: Chemical composition of particles 38.0 mg/m3 58.8 mg/m3 SEA-SPRAY 146.4 mg/m3 AFRICAN DUST IDENTIFICATION AND CHARACTERISATION OF NATURAL EVENTS:

38. C. Perrino C.N.R. Istituto sull’Inquinamento Atmosferico – Montelibretti (Roma) SECOND REMARK Natural events can be identified from an increase of the coarse-to-fine ratio and are characterised by advection conditions

39. STEP 3: Chemical composition of particles C. Perrino C.N.R. Istituto sull’Inquinamento Atmosferico – Montelibretti (Roma) ELEMENTAL CARBON PRIMARY ANTHROPOGENIC POLLUTANTS

40. STEP 3: Chemical composition of particles C.N.R. Institute of Atmospheric Pollution – Rome (ITALY) Average % composition of PM10 in the Lazio region

41. STEP 3: Chemical composition of particles C.N.R. Institute of Atmospheric Pollution – Rome (ITALY) Average % composition of PM2.5 in the Lazio region

42. C. Perrino C.N.R. Istituto sull’Inquinamento Atmosferico – Montelibretti (Roma) THIRD REMARK For primary anthropogenic pollutants we cannot identify “events” Their concentration depends on the proximity to the emission sources and their concentration variations mainly depend on the dispersion capacity of the lower atmosphere

43. STEP 3: Chemical composition of particles C. Perrino C.N.R. Istituto sull’Inquinamento Atmosferico – Montelibretti (Roma) SULPHATE SECONDARY POLLUTANTS

44. STEP 3: Chemical composition of particles C.N.R. Institute of Atmospheric Pollution – Rome (ITALY) Average % composition of PM10 in the Lazio region

45. STEP 3: Chemical composition of particles C.N.R. Institute of Atmospheric Pollution – Rome (ITALY) Average % composition of PM2.5 in the Lazio region

46. STEP 3: Chemical composition of particles C.N.R. Institute of Atmospheric Pollution – Rome (ITALY) PM10 Secondary pollutants are homogeneously distributed at least on a regional scale.

47. STEP 3: Chemical composition of particles C.N.R. Institute of Atmospheric Pollution – Rome (ITALY) PM10 PM2.5 PM10-2.5

48. C. Perrino C.N.R. Istituto sull’Inquinamento Atmosferico – Montelibretti (Roma) FOURTH REMARK For secondary pollutants we cannot identify “events” Their concentration is homogeneous on a regional scale and their concentration variations mainly depend on the dispersion capacity of the lower atmosphere

49. STEP 3: Chemical composition of particles PM10 concentration lower than 35 mg/m3 C.N.R. Institute of Atmospheric Pollution – Rome (ITALY) PM10 concentration higher than 65 mg/m3 PM composition during polluted days is very close to PM composition during clean days with the exception of days characterised by important natural events

50. THANK YOU FOR YOUR ATTENTION ! C. Perrino C.N.R. Istituto sull’Inquinamento Atmosferico – Montelibretti (Roma)