1. Nuclear Analytical Techniques in Particle Air Pollution Monitoring Septiembre 14, 2011 Grizel Pérez, Ibrahin Piñera Centro de Aplicaciones Tecnológicas y Desarrollo Nuclear CEADEN

2. ContentContent Introduction Introduction Nuclear Analytical Techniques in PM monitoring Nuclear Analytical Techniques in PM monitoring Physical PrinciplesPhysical Principles Main characteristicsMain characteristics PM samplingPM sampling Application example Application example Conclusions Conclusions G. Pérez Sept. 14 2011

3. IntroductionIntroduction G. Pérez Sept. 14 2011 Air pollution has become a matter of global concern, particularly in some of the world's largest cities. It is made up of many different components that affect the environment - and directly or indirectly the health of people. The main components include sulphur dioxide, particulate matter, carbon monoxide, reactive hydrocarbon compounds, nitrogen oxides, ozone, and lead. Nuclear techniques have important applications in the study of nearly all of them. However, it is in the study of airborne particulate matter (APM) that nuclear analytical techniques find many of their most important applications.

4. NATs in PM monitoring PM nuclear analysis methodsPM nuclear analysis methods Airborne particulate matter retained on the filter may be examined or analyzed chemically by a variety of methods. In this presentation, only nuclear analytical techniques (NATs) are considered because of their advantages in analyzing many elements in air particulate matter non- destructively and simultaneously. The key three NATs for analysis of particulate matter in air are: G. Pérez Sept. 14 2011

5. NATs in PM monitoring Airborne particulate matter retained on the filter may be examined or analyzed chemically by a variety of methods. In this presentation, only nuclear analytical techniques (NATs) are considered because of their advantages in analyzing many elements in air particulate matter non- destructively and simultaneously. The key three NATs for analysis of particulate matter in air are: PM nuclear analysis methodsPM nuclear analysis methods G. Pérez Sept. 14 2011

6. Physical Principles of NATs Neutron Activation Analysis (NAA)Neutron Activation Analysis (NAA) In typical NAA, a sample is exposed to a high flux of thermal neutrons in a nuclear reactor or accelerator. NAA is based on the interaction of a neutron (n) with a target nucleus ( A Z) where the neutron is captured and gamma rays are emitted. G. Pérez Sept. 14 2011

7. Physical Principles of NATs The spectrum of gamma rays energy determines the specific isotopes present in the sample. The intensity of the gamma rays is proportional to the amounts of elements present. Typically 5 counting regimes are required to detect these elements (300 s, 1 hr, 10 hr, 4 days and 15 days). It is highly sensitive (ppb), it does not quantify elements such as Si, Ni, Co, and Pb. Typical elemental detection limits range from 0.01 to 10 ng m -3. NAA is a simultaneous, multi-element method that can be used to measure 40-45 elements. Neutron Activation Analysis (NAA)Neutron Activation Analysis (NAA) In typical NAA, a sample is exposed to a high flux of thermal neutrons in a nuclear reactor or accelerator. NAA is based on the interaction of a neutron (n) with a target nucleus ( A Z) where the neutron is captured and gamma rays are emitted. G. Pérez Sept. 14 2011

8. X-Ray Fluorescence (XRF)X-Ray Fluorescence (XRF) XRF is based on the measurements of the energies and intensities of the characteristic X-rays excited in different materials by using an external source of electromagnetic radiation (usually X-ray tubes or radioisotope sources). Physical Principles of NATs G. Pérez Sept. 14 2011

9. X-Ray Fluorescence (XRF)X-Ray Fluorescence (XRF) XRF is based on the measurements of the energies and intensities of the characteristic X-rays excited in different materials by using an external source of electromagnetic radiation (usually X-ray tubes or radioisotope sources). XRF can be used for all elements with Z from 11 (Na) to 92 (U). Typical elemental detection limits for this method range between 2 and 2000 ng m -3. XRF depends on the availability of excellent PM standards. Shorter analysis time than NAA. XRF can be used for simultaneous determination of 20-25 elements. Physical Principles of NATs G. Pérez Sept. 14 2011

10. Ion Beam Analysis (IBA)Ion Beam Analysis (IBA) IBA is based on the interaction, at both the atomic and the nuclear level, between accelerated charged particles and the bombarded material. Physical Principles of NATs G. Pérez Sept. 14 2011

11. Ion Beam Analysis (IBA)Ion Beam Analysis (IBA) IBA is based on the interaction, at both the atomic and the nuclear level, between accelerated charged particles and the bombarded material. These techniques are used simultaneously as key analytical tools to assess PM pollution on a regular basis. The choice of analytical method depends on the inorganic compounds of interest and the detection limits desired. Using the four different analysis techniques (PIXE, PIGE, PESA, RBS), IBA can measure more than 40 elements (H – U). Physical Principles of NATs G. Pérez Sept. 14 2011

12. Particle Induced X-ray Emission Analysis (PIXE)Particle Induced X-ray Emission Analysis (PIXE) PIXE is a powerful and relatively simple analytical technique that can be used to identify and quantify trace elements typically ranging from Na to U. Sample irradiation is usually performed by means of 2-3 MeV protons produced by an accelerator. Xray detection is usually done by energy dispersive semiconductor detectors such as Si(Li) or HP Ge detectors. This multi-elemental analysis technique can measure more than 30 elements in short times due to higher cross-sections as compared to XRF. With the addition of PIGE and PESA, allows for the detection of light elements that is useful for source identification and apportionment and estimation of organic carbon. Typical detection limits range from 1 to 50 ng m -3. Physical Principles of NATs G. Pérez Sept. 14 2011

13. Particle Induced X-ray Emission Analysis (PIXE)Particle Induced X-ray Emission Analysis (PIXE) The remaining three methods are used simultaneously to achieve additional information on elements that can not or hardly be measured with PIXE. Physical Principles of NATs G. Pérez Sept. 14 2011

14. AdvantagesDisadvantages multielemental (H – U) non-destructive minimal sample preparation short irradiation time ( less than 15 min ) quick analysis for IBA ( typically 15 min ) high sensitivity good accuracy and precision can handle small samples (< 1 mg) IBA are cost effective for large sample numbers, more than 10 NAA is slow, requires multiple counting regimes to detect many elements NAA requires access to research nuclear reactor IBA requires access to particle accelerator impurities may be a problem matrix offsets and background standard/sample must match closely (matrix) XRF has particle size effects for low Z elements Main characteristics of NATs G. Pérez Sept. 14 2011

15. NATs in PM monitoring Typical load: 50 – 700 g/cm 2 Composition: Soil, soot, salts, industrial released Particle size: ~ 0.1 to 50 m Filter media: oTeflon oCellulose oMembrane (non-coated, coated) Dichotomous sampler (used under IAEA coordinated research projects and TC projects) (i) two fractions: 10 to 2.5 m and < 2.5 m (ii) 8 m and 0.4 m pore 47 mm Nuclepore Filters; Flow rate 16 lpm (iii) sampling time: 24 h for particle mass concentrations smaller than 50 g/m 3 ; Two days – 10-15 g/m 3 APM: usually collected by air filteringAPM: usually collected by air filtering NAA is compatible with sampling by high-volume (TSP; PM10) and dichotomous samplers. NAA is compatible with sampling by high-volume (TSP; PM10) and dichotomous samplers. Quartz filters used in high-volume samplers cause high background XRF and PIXE analysis, filters used in the dichotomous samplers are preferable. Quartz filters used in high-volume samplers cause high background XRF and PIXE analysis, filters used in the dichotomous samplers are preferable. PM2.5 collection by dichotomous samplers is typically involved by PIXE analysis. PM2.5 collection by dichotomous samplers is typically involved by PIXE analysis. G. Pérez Sept. 14 2011

16. Application example IAEA ARCAL Project RLA/7/ 011, ARCAL LXXX :IAEA ARCAL Project RLA/7/ 011, ARCAL LXXX : ASSESSMENT OF ATMOSPHERIC POLLUTANTS BY PARTICLES (2005-2008) General Objectives:General Objectives: To impel the research in the field of monitoring air pollution with emphasis on particles.To impel the research in the field of monitoring air pollution with emphasis on particles. Sample collection of airborne particulate matter (including course and fine) simultaneously.Sample collection of airborne particulate matter (including course and fine) simultaneously. The use of nuclear technology to characterize airborne particulate matter.The use of nuclear technology to characterize airborne particulate matter. Argentina, Chile, Costa Rica, Cuba, Dominican Republic, Mexico, Uruguay, Venezuela. G. Pérez Sept. 14 2011 CEADEN

17. Infanta Ave. & Manglar, Centro Habana, Havana City, Cuba. Urban site with high traffic and densely populated 23.12 N 82.4 W Environmental Monitoring Station

18. Sampling site at INHEM G. Pérez Sept. 14 2011

19. Possible pollution sites sampling site G. Pérez Sept. 14 2011

20. Samples and data collection Sampling period:Sampling period: November 14, 2006 to April, 2007.November 14, 2006 to April, 2007. Total 5 months.Total 5 months. Sampling frequency:Sampling frequency: Every second day with 24 h duration.Every second day with 24 h duration. Air Sampler type GENT with stacked filter unit for collecting the aerosol in two size fraction (PM 2,5 and PM 10 ) simultaneously. G. Pérez Sept. 14 2011

21. Samples preparation Microbalance: Cahn C-35 Resolution: 0.1 µg G. Pérez Sept. 14 2011

22. Gravimetric analysis Descriptive statistics of the data (µg/m 3 ). G. Pérez Sept. 14 2011

23. PIXE analysis sample Protons 2.5 MeV x I = 15 nA Q = 6 C Ortec Si(Li) detector active area = 80 mm 2 resolution = 200 eV at 5.9 keV (Mn-Kα, 55 Fe) Tandetron Accelerator, PIXE Analysis Lab. ININ, Mexico. G. Pérez Sept. 14 2011

24. 14 elements were consistently detected in the samples PIXE analysis G. Pérez Sept. 14 2011

25. Elemental analysis Softwares for spectra processing AXIL & WINAXIL_4.5.3 G. Pérez Sept. 14 2011

26. Partícula Fina Elemento (MDL) Partícula Gruesa MediaMaxMin nMediaMaxMin n (ng/m 3 ) 658.831711.14121.6843.3368S (28.50)429.031178.9191.4628.9271 65.77315.3711.784.0563Cl (11.60)1835.544108.1838.51123.7371 42.98209.805.822.8968K (4.40)117.36252.7231.407.9171 110.62515.4037.427.6568Ca (2.80)2029.864763.29312.31136.8371 5.0226.322.080.2032Ti (2.03)22.08115.083.031.4971 21.71115.350.171.3563V (1.88)13.5556.991.910.8566 3.0512.151.470.1855Cr (1.38)2.897.081.390.1862 10.48131.540.870.4341Mn (0.87)10.54146.741.080.7070 60.75655.9815.523.9667Fe (0.88)235.49852.9727.3915.6570 4.7221.650.990.2655Ni (0.95)3.7211.850.960.2466 2.4310.491.010.1453Cu (1.00)3.7811.641.020.2570 18.99293.111.201.2668Zn (1.20)18.3586.261.781.2471 9.0913.675.430.5660Br (5.30)7.1411.745.410.3224 10.5955.634.770.4335Pb (4.70)10.4539.794.820.5348 Todos los datos están referidos a los elementos que fueron encontrados por encima del LMD. Elemental analysis G. Pérez Sept. 14 2011

27. Elemental analysis G. Pérez Sept. 14 2011

28. Statistical analysis Descriptive statistic. Correlation Matrix. Principal Component Matrix. Rotated Principal Component Matrix by the maximum variability criteria. Component profiles and identification of the main sources (Factors). Scores of the found Factors. Contributions from sources to element concentrations. G. Pérez Sept. 14 2011

29. Rotated Principal Component Matrix fine mode G. Pérez Sept. 14 2011

30. Source identification & apportionment fine mode G. Pérez Sept. 14 2011

31. Sources apportionment fine mode G. Pérez Sept. 14 2011

32. coarse mode Rotated Principal Component Matrix G. Pérez Sept. 14 2011

33. coarse mode Source identification & apportionment G. Pérez Sept. 14 2011

34. coarse mode Sources apportionment G. Pérez Sept. 14 2011

35. ConclusionsConclusions Nuclear Analytical Techniques can be used for determination of the elemental composition of coarse and fine particulate matter: neutron activation analysis, X-ray fluorescence, and ion beam analysis (PIXE, PIGE, PESA, RBS). Since the various types of sources of particulate air pollutants are characterized by the elemental composition of the particles, knowledge of the elements in particles allows the identification of the origin of the particles and, thereby, leads to a quantitative apportionment of the existing types of sources. In consequence, most important source types can be identified and decisions can be made on which source types it is most appropriate to reduce emissions. This would constitute a valuable step forward in air quality management, particularly in cases where emissions inventories are not established. In our case, the results provided by PIXE in combination with appropriated statistical analysis allow us to identify the source profiles and contribution, providing important information about atmospheric pollution in selected site, necessary to develop strategies and to establish appropriate policies on pollution control. G. Pérez Sept. 14 2011

36. Nuclear Analytical Techniques can be used for determination of the elemental composition of coarse and fine particulate matter: neutron activation analysis, X-ray fluorescence, and ion beam analysis (PIXE, PIGE, PESA, RBS). Since the various types of sources of particulate air pollutants are characterized by the elemental composition of the particles, knowledge of the elements in particles allows the identification of the origin of the particles and, thereby, leads to a quantitative apportionment of the existing types of sources. In consequence, most important source types can be identified and decisions can be made on which source types it is most appropriate to reduce emissions. This would constitute a valuable step forward in air quality management, particularly in cases where emissions inventories are not established. In our case, the results provided by PIXE in combination with appropriated statistical analysis allow us to identify the source profiles and contribution, providing important information about atmospheric pollution in selected site, necessary to develop strategies and to establish appropriate policies on pollution control. ConclusionsConclusions G. Pérez Sept. 14 2011

37. Nuclear Analytical Techniques can be used for determination of the elemental composition of coarse and fine particulate matter: neutron activation analysis, X-ray fluorescence, and ion beam analysis (PIXE, PIGE, PESA, RBS). Since the various types of sources of particulate air pollutants are characterized by the elemental composition of the particles, knowledge of the elements in particles allows the identification of the origin of the particles and, thereby, leads to a quantitative apportionment of the existing types of sources. In consequence, most important source types can be identified and decisions can be made on which source types it is most appropriate to reduce emissions. This would constitute a valuable step forward in air quality management, particularly in cases where emissions inventories are not established. In our case, the results provided by PIXE in combination with appropriated statistical analysis allow us to identify the source profiles and contribution, providing important information about atmospheric pollution in selected site, necessary to develop strategies and to establish appropriate policies on pollution control. ConclusionsConclusions G. Pérez Sept. 14 2011

38. Nuclear Analytical Techniques can be used for determination of the elemental composition of coarse and fine particulate matter: neutron activation analysis, X-ray fluorescence, and ion beam analysis (PIXE, PIGE, PESA, RBS). Since the various types of sources of particulate air pollutants are characterized by the elemental composition of the particles, knowledge of the elements in particles allows the identification of the origin of the particles and, thereby, leads to a quantitative apportionment of the existing types of sources. In consequence, most important source types can be identified and decisions can be made on which source types it is most appropriate to reduce emissions. This would constitute a valuable step forward in air quality management, particularly in cases where emissions inventories are not established. In our case, the results provided by PIXE in combination with appropriated statistical analysis allow us to identify the source profiles and contribution, providing important information about atmospheric pollution in selected site, necessary to develop strategies and to establish appropriate policies on pollution control. ConclusionsConclusions G. Pérez Sept. 14 2011

39. Nuclear Analytical Techniques can be used for determination of the elemental composition of coarse and fine particulate matter: neutron activation analysis, X-ray fluorescence, and ion beam analysis (PIXE, PIGE, PESA, RBS). Since the various types of sources of particulate air pollutants are characterized by the elemental composition of the particles, knowledge of the elements in particles allows the identification of the origin of the particles and, thereby, leads to a quantitative apportionment of the existing types of sources. In consequence, most important source types can be identified and decisions can be made on which source types it is most appropriate to reduce emissions. This would constitute a valuable step forward in air quality management, particularly in cases where emissions inventories are not established. In our case, the results provided by PIXE in combination with appropriated statistical analysis allow us to identify the source profiles and contribution, providing important information about atmospheric pollution in selected site, necessary to develop strategies and to establish appropriate policies on pollution control. ConclusionsConclusions G. Pérez Sept. 14 2011

40. Thank you for your attention…