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 PM 10 network

Previous equivalence work in the UK May 99 to Oct 02, Published May 04 ( 6 sites Single PM 10 Kleinfiltergerat (KfG) and TEOM at each site Data evaluated using the then draft Guidance Expanded uncertainty of full data set = 30.5% - FAIL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 ( 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

Bristol East Kilbride Birmingham Teddington Sitetypewintersummer TeddingtonSuburban14/11/04 to 21/03/05 22/03/05 to 25/07/05 BirminghamUrban Background 28/11/04 to 22/03/05 23/03/05 to 22/07/05 East Kilbride Suburban13/10/05 to 12/01/06 01/08/05 to 12/10/05 BristolRoadside13/10/05 to 12/01/06 10/08/05 to 12/10/05

Equipment on the study PM 10 – Kleinfiltergerat (ref sampler) PM 10 Partisol 2025; PM 10 TEOM; PM 10 TEOM retrofitted with a Filter Dynamics Measurement System (FDMS); PM 10 OPSIS SM200, (SM200 Beta and SM200 Mass); PM 10 Met-One Beta Attenuation Monitor (BAM); PM 10 Met-One BAM retrofitted with a heater (Smart BAM); PM 2.5 – Kleinfiltergerat (ref sampler) PM 2.5 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 – o C 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 Expanded uncertainty: Annual LV = 32.68% Annual LV = 15.37% Daily LV = 40.38% Daily LV = 14.68%

Data examples: PM 2.5 FDMS TEOM Expanded uncertainty: Annual concentration cap = 24.45% Daily LV = not applicable

Results of the UK Study Candidate Instrument Equivalence Criteria Met?Correction Required Partisol 2025Meets criteriaNo correction required TEOMDoes not meet criteriaCorrection does not aid the adherence of equivalence criteria PM 10 FDMSMeets criteriaNo correction required PM 2.5 FDMSMeets criteriaNo correction required SM200 by BetaMeets criteriaNo correction required SM200 by MassMeets criteria after application of slope and intercept correction factors BAM † Meets criteria after application of a slope correction factor ambient conditions:

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

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 Policy Implications

Comparison of FDMS base vs TEOM 3 measurements from FDMS: non-volatile (base); volatile and total relationship between the FDMS base and TEOM measurements with and without the USEPA and UK correction factors: TEOM(0,1,1) = (PM 10 FDMS base )/1.360 TEOM(3,1.03,1.3) = PM 10 FDMS base

Summary Study report published 13 June 06 In the UK: TEOM fails equivalence tests Partisol 2025 Sequential Sampler; TEOM retrofitted with FDMS (for PM 10 and PM 2.5 ); and the OPSIS SM200 (by Beta) pass without correction OPSIS SM200 (by Mass) and Met One BAM pass with correction Have determined relationship between FDMS base and TEOM for future comparisons UK has commenced upgrading National Network initially using FDMS units retrofitted to existing TEOMs