PRACTICAL TESTING OF EQUIVALENCE IN THE UK by hcj

VIEWS: 0 PAGES: 16

									STUDY OF PM CORRECTION
FACTORS IN THE UK
Dr Janet Dixon
Department for Environment, Food and
Rural Affairs, UK
Content

•   Background to the UK equivalence study
•   UK equivalence study
•   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
•   Single PM10 Kleinfiltergerat (KfG) and TEOM at each site
•   Data evaluated using the then draft Guidance
•   Expanded uncertainty of full data set = 30.5% - FAIL
UK Equivalence study

• Began Mar 04, published June 06 (www.airquality.co.uk)
• Costs:
   • Equipment - £280,000 (400,000 Euros)
   • Study - £240,000 (345,000 Euros)
• 9 organisations involved
• Equipment on national network
• Other equipment offered by suppliers/ manufacturers
                                              Site         type       winter        summer


                                              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
                                              East         Suburban   13/10/05 to   01/08/05 to
                                              Kilbride                12/01/06      12/10/05
East Kilbride


                                              Bristol      Roadside   13/10/05 to   10/08/05 to
                                                                      12/01/06      12/10/05

                                       •


                          Birmingham




                                 Teddington

                Bristol
Equipment on the study

                   •   PM10 – Kleinfiltergerat (ref sampler)
                   •   PM10 Partisol 2025;
                   •   PM10 TEOM;
                   •   PM10 TEOM retrofitted with a Filter
                       Dynamics Measurement System
                       (FDMS);
                   •   PM10 OPSIS SM200, (SM200 Beta
                       and SM200 Mass);
                   •   PM10 Met-One Beta Attenuation
                       Monitor (BAM);
                   •   PM10 Met-One BAM retrofitted with a
                       heater (Smart BAM);
                   •   PM2.5 – Kleinfiltergerat (ref sampler)
                   •   PM2.5 TEOM retrofitted with an
                       FDMS .
Practical Problems encountered

•   KfG –samplers stopping at high temp and %RH
•   Partisol – minor problems
•   TEOM – minor problems
•   FDMS – sensitive to temp of station – 18-22oC
•   SM200 – filter identification; initial filter thickness
•   BAM – leak flow test failures
•   Smart BAM – major problems with initial set-up –
    excluded from statistical analysis
Summary of deviations from CEN
standards and Equivalence Guidance
• EN12341 – teflon coated glass fibre filters used
• EN14907 – no commercially available monitors
• Equivalence Guidance
   • outliers due to human error rather than instrument error
   • slopes of all datasets were all greater or all less than 1,
      and/or the intercepts of all datasets were all greater or
      all less than zero
   • failure on WCM for the <50 % LV dataset alone
• Logic steps to determine whether an instrument meets the
  criteria for equivalence
        Data examples:
        TEOM(3,1.03,1.3) and FDMS TEOM
                             80                                                                           80



                             70                                                                           70
                                                                                               Birm ingham Winter                                                  Birm i

                                                                                               Birm ingham Sum m er                                                Birm i
                             60                                                                           60
                                                                                               Teddington Winter                                                   Tedd
TEOM (3,1.03,1.3) / μg m-3




                                                                                               Teddington Sum m er                                                 Tedd




                                                                                     PM10 FDMS / μg m-3
                             50                                                                Bris50 Winter
                                                                                                   tol                                                             Bris to

                                                                                               Bris tol Sum m er                                                   Bris to
                             40                                                                Eas40
                                                                                                  t Kilbride Winter                                                Eas t

                                                                                               Eas t Kilbride Sum m er                                             Eas t

                             30                                                                < 25 μg m -3 Line
                                                                                                   30                                                              < 25

                                                                                               > 25 μg m -3 Line                                                   > 25

                             20                                                                < 20 μg m -3 Line                                                   < 20
                                                                                                          20
                                                                                               > 20 μg m -3 Line                                                   > 20

                                                                                               All Data Line                                                       All Da
                             10                                                                           10


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




Expanded uncertainty:
• Annual LV = 32.68%                                                                                      Annual LV = 15.37%
• Daily LV = 40.38%                                                                                       Daily LV = 14.68%
                          Data examples:
                          PM2.5 FDMS TEOM
                    70



                    60
                                                                                Expanded uncertainty:
                    50
                                                                                • Annual concentration cap
                                                                                 Birmingham Winter

                                                                                 Birmingham Summer


                                                                                  = 24.45%
                                                                                 Teddington Winter
-3
PM2.5 FDMS / μg m




                    40                                                           Teddington Summer


                                                                                • Daily LV = not applicable
                                                                                 Bristol Winter

                    30                                                           Bristol Summer

                                                                                 East Kilbride Winter

                    20                                                           East Kilbride Summer

                                                                                 < 12.5 μg m-3 Line

                    10                                                           > 12.5 μg m-3 Line

                                                                                 All Data Line

                     0



                    -10
                          -10   0   10   20     30      40       50   60   70
                                         PM2.5 Leckel / μg m-3
Results of the UK Study
Candidate       Equivalence Criteria Met?      Correction Required
Instrument
Partisol 2025   Meets criteria                 No correction required

TEOM            Does not meet criteria         Correction does not aid the
                                               adherence of equivalence
                                               criteria
PM10 FDMS       Meets criteria                 No correction required

PM2.5 FDMS      Meets criteria                 No correction required

SM200 by Beta   Meets criteria                 No correction required

SM200 by Mass   Meets criteria after           SM 200MassCorrected 
                                                                       SM 200Mass  1.286
                application of slope and                                      0.819

                intercept correction factors
BAM†            Meets criteria after           ambient conditions:
                                                                         BAM Ambient
                application of a slope         BAM Ambient Corrected 
                                                                           1.273
                correction factor
Policy Implications

• TEOM – UK currently applies the ‘consistent’ relationship
  allowed in the Directive
• TEOM x 1.3 is overly conservative at some sites
• Although non-equivalent – broad conclusions from TEOM
  will be same as those from equivalent instruments
   • elevated levels of PM in some places; and
   • particles pose a large public health risk across the UK
• Checking of UK national modelling will be affected
Policy Implications

• UK has begun a transitional period of making the network
  equivalent – initially using FDMS units retrofitted to
  existing TEOMs
• UK local authorities can continue to use TEOMs to fulfil
  their obligations under the Local Air Quality Management
  regime
• Implications on any epidemiology studies currently
  underway
Comparison of FDMSbase vs TEOM

• 3 measurements from FDMS: non-volatile (base);
  volatile and total
• relationship between the FDMSbase and TEOM
  measurements with and without the USEPA and
  UK correction factors:
• TEOM(0,1,1) = (PM10 FDMSbase+ 2.061)/1.360
• TEOM(3,1.03,1.3) = PM10 FDMSbase+ 5.826
Summary

• Study report published 13 June 06
• In the UK:
   • TEOM fails equivalence tests
   • Partisol 2025 Sequential Sampler; TEOM retrofitted
      with FDMS (for PM10 and PM2.5); and the OPSIS
      SM200 (by Beta) pass without correction
   • 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

								
To top