Practical Testing of Equivalence in the UK Janet Dixon - DEFRA_ UK

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					                                 Practical Testing of Equivalence in the UK




PRACTICAL TESTING OF                                          Content
EQUIVALENCE IN THE UK
Dr Janet Dixon                                                •   Background to the UK equivalence study
Department for Environment, Food and                          •   UK equivalence study
Rural Affairs, UK                                             •   Criteria used
                                                              •   Results + problems
                                                              •   Equivalence Guidance
                                                              •   Policy issues




Current UK PM10 network
                                                              Previous equivalence work in the UK

                                                              •   May 99 to Oct 02,
                                                              •   Published May 04 (www.airquality.co.uk)
                                                              •   6 sites
                                                              •   PM10 Kleinfiltergerat (KfG) and TEOM at each site
                                                              •   Data evaluated using the then draft Guidance
                                                              •   Expanded uncertainty of full data set = 30.5% - FAIL




                                                                                                                   Site         type       winter        summer

UK Equivalence study                                                                                               Teddington   Suburban   14/11/04 to   22/03/05 to
                                                                                                                                           21/03/05      25/07/05
                                                                                                                   Birmingham Urban      28/11/04 to     23/03/05 to
                                                                                                                              Background 22/03/05        22/07/05
• Began Mar 04, ended June 06
                                                                                                                   East         Suburban   13/10/05 to   01/08/05 to
• Costs:                                                                                                           Kilbride                12/01/06      12/10/05
                                                                     East Kilbride

   • Equipment - £280,000 (400,000 Euros)                                                                          Bristol      Roadside   13/10/05 to   10/08/05 to
                                                                                                                                           12/01/06      12/10/05
   • Study - £240,000 (345,000 Euros)
• 8 organisations involved                                                                                  •
• Equipment on national network
• Other equipment offered by suppliers/ manufacturers                                          Birmingham




                                                                                                      Teddington

                                                                                     Bristol




                                              Janet Dixon - DEFRA, UK
                                                                                                                                                                       1
                                                                                       Practical Testing of Equivalence in the UK




                      Equipment on the study
                                                                                                                                   Practical Problems encountered
                                                                                •   PM10 – Kleinfiltergerat (ref sampler)
                                                                                •   PM10 Partisol 2025;
                                                                                •   PM10 TEOM;
                                                                                                                                   •                      KfG –samplers stopping at high temp and %RH
                                                                                •   PM10 TEOM retrofitted with a Filter
                                                                                    Dynamics Measurement System                    •                      Partisol – minor problems
                                                                                    (FDMS);                                        •                      TEOM – minor problems
                                                                                •   PM10 OPSIS SM200, (SM200 Beta                  •                      FDMS – sensitive to temp of station – 18-22oC
                                                                                    and SM200 Mass);
                                                                                •   PM10 Met-One Beta Attenuation                  •                      SM200 – filter identification; initial filter thickness
                                                                                    Monitor (BAM);                                 •                      BAM – leak flow test failures
                                                                                •   PM10 Met-One BAM retrofitted with a            •                      Smart BAM – major problems with initial set-up –
                                                                                    heater (Smart BAM);
                                                                                                                                                          excluded from statistical analysis
                                                                                •   PM2.5 – Kleinfiltergerat (ref sampler)
                                                                                •   PM2.5 TEOM retrofitted with an
                                                                                    FDMS .




                          Summary of deviations from CEN                                                                           Data examples:
                          standards and Equivalence Guidance                                                                       TEOM(3,1.03,1.3) and FDMS TEOM
                                                                                                                                                     80                                                                       80

                          • EN12341 – teflon coated glass fibre filters used                                                                         70                                                                       70



                          • EN14907 – no commercially available monitors                                                                             60                                                                       60
                                                                                                                             -3
                                                                                                                              T O (3 .0 ,1 ) / µ m




                                                                                                                                                                                                            -3
                                                                                                                                                g




                                                                                                                                                                                                             P 10 F M / µ m
                          • Equivalence Guidance
                                                                                                                                                     50                                                                       50




                                                                                                                                                                                                              M D S g
                                                                                                                               E M ,1 3 .3




                                                                                                                                                     40                                                                       40


                             • outliers due to human error rather than instrument error                                                              30                                                                       30




                             • slopes of all datasets were all greater or all less than 1,                                                           20                                                                       20


                                                                                                                                                     10                                                                       10

                                and/or the intercepts of all datasets were all greater or                                                             0                                                                        0


                                all less than zero                                                                                                        0   10   20   30    40      50
                                                                                                                                                                                        -3
                                                                                                                                                                         PM 10 KFG / µg m
                                                                                                                                                                                             60   70   80                          0   10     20      30          40
                                                                                                                                                                                                                                                         PM 10 KFG / µg m
                                                                                                                                                                                                                                                                          50
                                                                                                                                                                                                                                                                            -3
                                                                                                                                                                                                                                                                                    60   70   80




                             • failure on WCM for the <50 % LV dataset alone                                                 Expanded uncertainty:
                          • Logic steps to determine whether an instrument meets the                                         • Annual LV = 32.68%                                                                             Annual LV = 15.37%
                            criteria for equivalence                                                                         • Daily LV = 40.38%                                                                              Daily LV = 14.68%




                                                                                                                             Results of the UK Study
                          Data examples:                                                                                                      Candidate
                                                                                                                                              Instrument
                                                                                                                                                                             Equivalence Criteria Met?                                 Correction Required

                          PM2.5 FDMS TEOM                                                                                                     Partisol 2025                  Meets criteria                                            No correction required

                    70
                                                                                                                                              TEOM                           Does not meet criteria                                    Correction does not aid the
                    60
                                                                                    Expanded uncertainty:                                                                                                                              adherence of equivalence
                                                                                                                                                                                                                                       criteria
                    50
                                                                                    • Annual concentration cap
                                                                                                                                              PM10 FDMS                      Meets criteria                                            No correction required
                                                                                      = 24.45%
-3
PM2.5 FDMS / µg m




                    40

                                                                                    • Daily LV = not applicable                               PM2.5 FDMS                     Meets criteria                                            No correction required
                    30



                    20
                                                                                                                                              SM200 by Beta                  Meets criteria                                            No correction required
                    10

                                                                                                                                              SM200 by Mass                  Meets criteria after
                                                                                                                                                                                                                                        SM 200MassCorrected =
                                                                                                                                                                                                                                                                  (SM 200Mass − 1.286)
                     0
                                                                                                                                                                             application of slope and                                                                       0.819

                    -10
                                                                                                                                                                             intercept correction factors
                          -10   0   10   20     30      40       50   60   70
                                         PM2.5 Leckel / µg m-3                                                                                BAM†                           Meets criteria after                                      ambient conditions:
                                                                                                                                                                                                                                                                       BAM Ambient
                                                                                                                                                                             application of a slope                                     BAM Ambient   Corrected   =
                                                                                                                                                                                                                                                                         1.273
                                                                                                                                                                             correction factor




                                                                                                       Janet Dixon - DEFRA, UK
                                                                                                                                                                                                                                                                                                   2
                                   Practical Testing of Equivalence in the UK




Policy Implications                                             Policy Implications

• TEOM – UK currently applies the ‘consistent’ relationship     • UK has begun a transitional period of making the network
  allowed in the Directive                                        equivalent – initially using FDMS units retrofitted to
• TEOM x 1.3 is overly conservative at some sites                 existing TEOMs
• Although non-equivalent – broad conclusions from TEOM         • UK local authorities can continue to use TEOMs to fulfil
  will be same as those from equivalent instruments               their obligations under the Local Air Quality Management
   • elevated levels of PM in some places; and                    regime
   • particles pose a large public health risk across the UK    • Implications on any epidemiology studies currently
• Checking of UK national modelling will be affected              underway




Comparison of FDMSbase vs TEOM                                  Summary

                                                                • Study report published 13 June 06
• relationship between the FDMSbase measurement                 • In the UK:
  and TEOM with and without the USEPA and UK                       • TEOM fails equivalence tests
  correction factors:                                              • Partisol 2025 Sequential Sampler; TEOM retrofitted
• TEOM(0,1,1) = (PM10 FDMSbase+ 2.061)/1.360                          with FDMS (for PM10 and PM2.5); and the OPSIS
                                                                      SM200 (by Beta) pass without correction
• TEOM(3,1.03,1.3) = PM10 FDMSbase+ 5.826                          • OPSIS SM200 (by Mass) and Met One BAM pass with
                                                                      correction
                                                                   • Have determined relationship between FDMSbase and
                                                                      TEOM for future comparisons
                                                                • UK has commenced upgrading National Network initially
                                                                  using FDMS units retrofitted to existing TEOMs




                                                Janet Dixon - DEFRA, UK
                                                                                                                             3

				
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