Air quality expert group - Fine particulate matter (PM2.5) in ... - Defra

More documents

Recommendations

Info

Measuring PM2.5 and its components • There are long periods of negative concentrations both for the volatile and non-volatile components of the PM2.5 at this location, which cannot be exactly correct. However, this feature is particularly apparent because of the low concentrations, and the measurements still fall within the uncertainties of the method and based on current reporting rules would pass as ratified. • In some cases FDMS instruments are prone to reporting negative data after a filter change but in this case it is clearly a more general problem. Instrument filter changes are however recommended to be undertaken only when essential, and the AURN QA/QC Unit has worked closely with the FDMS instrument supplier to develop upgraded filter changing procedures. Concentration / µg m -3 40 35 30 25 20 15 10 5 0 -5 -10 Jan-11 Feb-11 Mar-11 Auchencorth Moss PM 2.5 FDMS Measurements Apr-11 May-11 Jun-11 Jul-11 Aug-11 FDMS Non-Volatile (Base) Figure 2.4: Example FDMS data. The y-axis shows the volatile and non-volatile components of PM2.5 in µg m -3 . 41. For correct operation, FDMS instruments must operate within certain temperature and humidity tolerances. Hence, the ratification process also closely inspects these data. As a general rule there must always be at least 4°C separation between the internal and external dew points to prevent moisture condensation on the filter. 42. Provisional non-automatic (Partisol) PM2.5 daily mean measurements are calculated by the CMCU from the change in mass of weighed filters following exposure to ambient air. The relevant instrument flow rates, filter exposure period, instrument alarms and diagnostics are all required for data ratification by the QA/QC Unit. Sep-11 Oct-11 Nov-11 Dec-11 31
PM2.5 in the UK 32 43. Ratification of the data will include checking that all instrument operating parameters are within specification and that the resulting measurements compare sensibly with other monitoring data at this site or from nearby locations (explained in more detail in Section 2.3.7). 2.3.7 Comparison with other data 44. In the case of PM2.5 monitoring one of the most important data ratification checks is comparison with other data, both other pollutants monitored at the same site and PM2.5 monitored on a regional basis. The two key criteria are as follows: • Are PM2.5 measurements at a site generally less than co-located PM10 concentrations as you would expect (allowing for occasional excursions within instrument uncertainties)? • Are the volatile PM2.5 measurements at a site consistent with regional concentrations? QA/QC checks can easily be put in place to review instrument performance against these criteria. 45. Firstly, calculation and plotting of the daily difference between PM10 and PM2.5 measurements from co-located instruments will show if there is any substantial bias towards PM2.5 concentrations exceeding PM10. Of course this will not identify in itself whether there is a problem with the PM2.5 instrument overreading or PM10 instrument under-reading. This decision will need to be made through interpretation of audit results, instrument servicing reports and using the experience of the QA/QC Unit. 46. Secondly, plotting regional volatile PM2.5 data, together with statistical analysis, can enable the identification of any monitoring sites that may be operating as outliers. If outliers are detected then it may be that such data are invalid, depending of course on the number and quality of the other measurements in the region against which they are being compared. An example of regional volatile PM2.5 data is shown in Figure 2.5. In this case further investigation would be required for London Harlington and Camden Kerbside which appear to be high and low respectively compared to the regional mean.
Page 1 and 2: AIR QUALITY EXPERT GROUP Fine Parti
Page 3 and 4: This is a report from the Air Quali
Page 5 and 6: II Membership Chair Professor Paul
Page 7 and 8: IV Acknowledgements The Air Quality
Page 9 and 10: VI 2.5 Summary 39 2.5.1 What does t
Page 11 and 12: VIII 5.4 Components of PM2.5 and so
Page 13 and 14: PM2.5 in the UK 2 Air Quality Direc
Page 15 and 16: PM2.5 in the UK 4 I.2.1 Concentrati
Page 17 and 18: PM2.5 in the UK 6 • PM2.5 emissio
Page 19 and 20: PM2.5 in the UK 8 I.4.1 Modelling r
Page 21 and 22: PM2.5 in the UK 10 4. In broad term
Page 23 and 24: PM2.5 in the UK Table 1.2: National
Page 25 and 26: PM2.5 in the UK 14 17. Dry depositi
Page 27 and 28: PM2.5 in the UK 16 in ozone in the
Page 29 and 30: PM2.5 in the UK 18
Page 31 and 32: PM2.5 in the UK 20 5. The exact for
Page 33 and 34: PM2.5 in the UK 22 12. These diffic
Page 35 and 36: PM2.5 in the UK 24 2.3 Methods used
Page 37 and 38: PM2.5 in the UK 26 (e) During the
Page 39 and 40: PM2.5 in the UK 28 2.3.3 The Partis
Page 41: PM2.5 in the UK 30 35. For non-auto
Page 45 and 46: PM2.5 in the UK 34 49. Many of the
Page 47 and 48: PM2.5 in the UK 36 57. Black carbon
Page 49 and 50: PM2.5 in the UK 38 2.4.4 PM2.5 elem
Page 51 and 52: PM2.5 in the UK 40 average of 93.6%
Page 53 and 54: PM2.5 in the UK Annex 1 - PM2.5 mon
Page 55 and 56: PM2.5 in the UK 44
Page 57 and 58: PM2.5 in the UK 46 3.2.1 Diurnal va
Page 59 and 60: PM2.5 in the UK 48 PM2.5/µgm -3 20
Page 61 and 62: PM2.5 in the UK 50 3.2.4 Seasonal v
Page 63 and 64: PM2.5 in the UK 52 12. Results are
Page 65 and 66: PM2.5 in the UK 54 3.4.2 Relationsh
Page 67 and 68: PM2.5 in the UK 56 Correlation 0.8
Page 69 and 70: PM2.5 in the UK Figure 3.11: Polar
Page 71 and 72: PM2.5 in the UK 60 south. Further a
Page 73 and 74: PM2.5 in the UK 62 3.7 PM2.5 episod
Page 75 and 76: PM2.5 in the UK 64 secondary ammoni
Page 77 and 78: PM2.5 in the UK 66 3.8 PM2.5 concen
Page 79 and 80: PM2.5 in the UK 68 3.9 Composition
Page 81 and 82: PM2.5 in the UK 70 43. The UK has i
Page 83 and 84: PM2.5 in the UK 72 NO 3 6 4 2 2000
Page 85 and 86: PM2.5 in the UK 74 54. PM ammonium
Page 87 and 88: PM2.5 in the UK 76 58. Data from th
Page 89 and 90: PM2.5 in the UK 78 (k) Road traffic
Page 91 and 92: PM2.5 in the UK 80 provided by spec
Page 93 and 94:
PM2.5 in the UK 82 14. The London L
Page 95 and 96:
PM2.5 in the UK Table 4.1: UK emiss
Page 97 and 98:
PM2.5 in the UK 86 24. National inv
Page 99 and 100:
PM2.5 in the UK 88 Figure 4.5: Spat
Page 101 and 102:
PM2.5 in the UK 90 either nanoparti
Page 103 and 104:
PM2.5 in the UK 92 37. Further cons
Page 105 and 106:
PM2.5 in the UK Emissions (ktonnes)
Page 107 and 108:
PM2.5 in the UK 96 Figure 4.7: Spat
Page 109 and 110:
PM2.5 in the UK 98 4.4 A critical a
Page 111 and 112:
PM2.5 in the UK 100 60. At a local
Page 113 and 114:
PM2.5 in the UK 102 measurements an
Page 115 and 116:
PM2.5 in the UK 104 4.5.2 Quantifyi
Page 117 and 118:
PM2.5 in the UK 106 77. Early effor
Page 119 and 120:
PM2.5 in the UK 108 4.6.1 Receptor
Page 121 and 122:
PM2.5 in the UK 110 is predicated o
Page 123 and 124:
PM2.5 in the UK 112 PM2.5 contribut
Page 125 and 126:
PM2.5 in the UK 114 inorganic parti
Page 127 and 128:
PM2.5 in the UK 116 93. While there
Page 129 and 130:
PM2.5 in the UK 118 100% 90% 80% 70
Page 131 and 132:
PM2.5 in the UK 120 105. Receptor m
Page 133 and 134:
PM2.5 in the UK 122
Page 135 and 136:
PM2.5 in the UK 124 5. At the regio
Page 137 and 138:
PM2.5 in the UK 126 15. Some of the
Page 139 and 140:
PM2.5 in the UK 128 Figure 5.2: Tot
Page 141 and 142:
PM2.5 in the UK 130 µgm -3 160 140
Page 143 and 144:
PM2.5 in the UK 132 PM component (
Page 145 and 146:
PM2.5 in the UK 134 with larger dev
Page 147 and 148:
PM2.5 in the UK 136 Figure 5.8: UKI
Page 149 and 150:
PM2.5 in the UK Figure 5.9: Compari
Page 151 and 152:
PM2.5 in the UK 140 PM2.5 concentra
Page 153 and 154:
PM2.5 in the UK 142 the North Sea (
Page 155 and 156:
PM2.5 in the UK 144 53. Modelling r
Page 157 and 158:
PM2.5 in the UK Annex 2: PM modelli
Page 159 and 160:
PM2.5 in the UK 148 2. Figure A2.1.
Page 161 and 162:
PM2.5 in the UK 150 6. The non-line
Page 163 and 164:
PM2.5 in the UK 152 Model 50 45 40
Page 165 and 166:
PM2.5 in the UK 154 (a) (b) modPM 2
Page 167 and 168:
PM2.5 in the UK 156 NO3 - concentra
Page 169 and 170:
PM2.5 in the UK 158 26. This was in
Page 171 and 172:
PM2.5 in the UK 160 SIA components
Page 173 and 174:
PM2.5 in the UK 162 x 50 km grid fo
Page 175 and 176:
PM2.5 in the UK 164 A2.6: Photochem
Page 177 and 178:
PM2.5 in the UK 166 PM2.5 Emission
Page 179 and 180:
PM2.5 in the UK 168 A2.8: PCM PM mo
Page 181 and 182:
PM2.5 in the UK 170 illustrated by
Page 183 and 184:
PM2.5 in the UK 172 trajectory mode
Page 185 and 186:
PM2.5 in the UK 174
Page 187 and 188:
PM2.5 in the UK 176 4. The delivery
Page 189 and 190:
PM2.5 in the UK 178 12. With respec
Page 191 and 192:
PM2.5 in the UK 180
Page 193 and 194:
PM2.5 in the UK Chapter 2: Measurin
Page 195 and 196:
PM2.5 in the UK RoTAP (2012). Revie
Page 197 and 198:
PM2.5 in the UK Harrison R.M. and Y
Page 199 and 200:
PM2.5 in the UK Chapter 5 Modelling
Page 201 and 202:
PM2.5 in the UK Jones A.M., Harriso
Page 203:
PB13837 Nobel House 17 Smith Square
show all

Air quality expert group - Fine particulate matter (PM2.5) in ... - Defra

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?