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

3. 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?
C. Perrino C.N.R. Istituto sull’Inquinamento Atmosferico – Montelibretti (Roma)

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

5. C. PERRINO - C.N.R. Institute of Atmospheric Pollution
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. 3-step procedure: Natural radioactivity monitoring
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
C.N.R. Institute of Atmospheric Pollution – Rome (ITALY)

7. about the air volume available for pollution dispersion
atmospheric concentration of pollutants
emission
(and physico-chemical trasnformation)
mixing properties
of the lower
atmosphere
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
C.N.R. Institute of Atmospheric Pollution – Rome (ITALY)

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

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

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

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
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
C. Perrino C.N.R. Istituto sull’Inquinamento Atmosferico – Montelibretti (Roma)

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

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

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

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

20. 3-step procedure: Natural radioactivity monitoring
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
C.N.R. Institute of Atmospheric Pollution – Rome (ITALY)

21. STEP 2: Size distribution of particulate matter
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; – 10 m
C.N.R. Institute of Atmospheric Pollution – Rome (ITALY)

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

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

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

25. 3-step procedure: Natural radioactivity monitoring
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
C.N.R. Institute of Atmospheric Pollution – Rome (ITALY)

26. STEP 3: Chemical composition of particles
Ion chromatography (IC)
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)
Termo-optical analyser
X-ray fluorescence (ED-XRF)
Sampling by diffusion lines
and IC analysis
C.N.R. Institute of Atmospheric Pollution – Rome (ITALY)

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

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

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

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

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

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

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

36. STEP 3: Chemical composition of particles
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 cause an increase of PM2.5 concentration
C.N.R. Institute of Atmospheric Pollution – Rome (ITALY)

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

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

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

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

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

42. For primary anthropogenic pollutants we cannot identify “events”
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
C. Perrino C.N.R. Istituto sull’Inquinamento Atmosferico – Montelibretti (Roma)

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

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

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

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

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

48. For secondary pollutants we cannot identify “events”
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
C. Perrino C.N.R. Istituto sull’Inquinamento Atmosferico – Montelibretti (Roma)

49. PM composition during polluted days
STEP 3: Chemical composition of particles
PM10 concentration lower than 35 mg/m3
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
C.N.R. Institute of Atmospheric Pollution – Rome (ITALY)

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

51. STEP 3: Chemical composition of particles

52. PM10 - 2.5 FASE 3: COMPOSIZIONE CHIMICA DEL MATERIALE PARTICELLARE
SIA L’AEROSOL MARINO CHE LE SPECIE DI DERIVAZIONE TERRIGENA
SONO UNA COMPONENTE QUANTITATIVAMENTE IMPORTANTE
DELLA FRAZIONE COARSE
C. Perrino C.N.R. Istituto sull’Inquinamento Atmosferico – Montelibretti (Roma)