QA QC of Scottish Air Quality Data Ken Stevenson

QA/QC of Scottish Air Quality Data Ken Stevenson

Project Overview Aim : • To have all of the air quality data collected in Scotland in one accessible website Duration: • 3 -year contract Key elements: • Data from National Network and LA sites in Scotland • All quality assured to same standard • Data available via open access website • Long-term trend analysis • Mapping of pollutants throughout Scotland • Newsletter and Annual Report • Annual Seminar

QA/QC of Scottish sites Current Situation – Total 60 Sites on Scottish website (up from 44 in 2007) • 32 sites operated under this project • 15 AURN • 13 funded by LAs or Scottish Grant Scheme

Additional sites to be added 5 sites temporily closed for relocation or roadworks • Fife Cupar • Edinburgh Haymarket • Aberdeen Market St • N. Lanarkshire, Harthill • N Lanarkshire, Ellis Road 4 sites still to join the database • East Lothian, Mussleburgh North High St – In progress • East Renfrewshire, Clarkston – In progress • Shetland Stanley Hill – telemetry issues • North Ayrshire, Irvine – New site recently installed This will bring the total to 69 sites on the Scottish Database.

QA/QC • • • Daily collection of data from each site Scaling of data from last calibration results Daily checking of data On-going data update as new information becomes available Site audits Collection and storage of all calibrations and service records etc 6 -monthly data ratification “Quality Circle” data review Update of ratified data to the website Assistance to LAs where-ever possible

Site Audits 2008/9

6 -monthly site intercalibration and audit AEA visits every site every 6 months to undertake the intercalibration and site audit • • Check Analysers Check Calibration Gases Site Infrastructure Local Operator 0401

Problems found at 2008/9 audits • Cylinders: - 4 NO cylinders 1 SO 2 Cylinder • PM Analysers: - 2 Ko out by more than 2. 5% (2. 8 – 4. 8%) 5 Main flows out (12 – 20%) 6 Leak test failed 1 Aux flow out (26%) • Gas Analysers 1 CO analyser fail leak test

Feedback from site visits

Data Ratification

Example of Data Summary Sheet

Measuring PM PM 10 “Equivalent Analysers” • • • Partisol (with emfab filters) Beta (Met One) unheated, with correction factor Beta (Opsis SM 200) with correction factor TEOM FDMS (not with C drier) (TEOM with Volatile Correction Model)

Partisol §Automated sampling device - sizeselected particulate matter on filters for later analysis. §Unattended operation for up to two weeks between site visits. §Filters are equilibrated, at 20° C and 50% R. H. , for 48 hours - before and again after sampling. §Filters are carefully weighed using precision microbalances. §Concentration is a function of air volume sampled and weight PM of material on filter.

Scottish Government Partisol Monitoring Programme 2007 • PM 10 and PM 2. 5 at 5 sites for 1 year • Data problems common to all UK Partisol measurements • High field blank due to moisture • Worst with Quartz filters – even though these are specified in EU PM 10 standard • Data now corrected and reported • Data used for PM Mapping in Scotland • Changed to Emfab filters in AURN

BAM (Beta Attenuation Monitor) §Size-selected particulate matter on filter tape §Analysed by attenuation of Beta rays from Carbon-14 source §Zero from clean filter compared to soiled filter §Algorithm to calculate mass from attenuation §Correction factor may be required for equivalence

FDMS

FDMS Operation Issues • Filter Changing • Possible long-term problems with FDMS C system • Use B or CB type drier

PM 10 Monitoring in the Scottish Database 45 monitors in total • FDMS 12 • BAM 4 • TEOM 29

Conclusions • • • QA/QC work is key to everything Audits and Ratification are a major part of the project work PM - Partisol issues resolved FDMS and BAM Equivalent PM analysers being deployed We strive to support and work closely with LAs – – – respond to requests and enquiries offer advice feedback if we see problems with the data chase for calibrations • The database is building rapidly 2006 – ~20 sites 2007 – 44 sites 2008 – 60 sites