Results of the second comparison exercise for EU National Air Quality Reference Laboratories (AQUILA) for TC, OC and EC measurement (2011)

The EC-JRC European Reference Laboratory for Air Pollution (ERLAP) has organized an inter-laboratory comparison for the measurement of total carbon (TC), elemental carbon (EC) and organic carbon (OC) in particulate matter collected on filters. To this comparison seventeen European Union National Reference Laboratories for air quality or delegated organizations participated, all using thermal optical analysis with the same analyzer (Sunset Lab off-line carbon analyzer). The aim of this comparison was to evaluate the performances of participants but also to study the effects of applying different thermal protocols, i.e. NIOSH and EUSAAR_2 protocols, currently in use in Europe for such analysis. In absence of a general consensus by the scientific community on the definition of a reference material for EC and, thus, of an standard reference analytical method, method performances [ISO5725-2] and laboratory performances [ISO 13528:2005(E)] were evaluated for TC and EC/TC ratio in the present comparison exercise. For TC, repeatability and reproducibility relative standard deviations ranged from 2% to 6% (sr = 0.017 × m + 0.227) and from 5% to 11% (sR = 0.038 × m + 0.389), respectively. For EC/TC ratio, repeatability and reproducibility relative standard deviations ranged from 2% to 10% and from 8% to 35%, respectively for the NIOSH-like protocol, and from 2% to 14% and from 4% to 19%, respectively for the EUSAAR protocol. (No satisfactory dependence was found upon EC/TC ratio). Furthermore, based on z-scores, three outliers were identified in the TC database when applying as standard deviation for proficiency assessment, σ*, that one calculated from data obtained in a round of a proficiency testing scheme. These outliers would also not comply with the DQO (i.e. expanded uncertainty, with a coverage factor of 2) of 25%, as in the EU Directive 2008/50/EC for PM at its limit value of 50 µg m-3. Laboratory performances were evaluated for EC/TC ratio, separately on the two data subsets from the NIOSH and EUSAAR_2 protocols using as σ* a common level of performance (i.e. 15%) that the inter-laboratory comparison coordinator would wish participants to achieve. Under this condition, four outliers were identified in the subset of data from the NIOSH-like protocol and one outlier in the subset of data from the EUSAAR_2 protocol.JRC.H.2-Air and Climat

Measuring air pollution with low-cost sensors

Low-cost air quality sensors are attracting more and more attention. They offer air pollution monitoring at a lower cost than conventional methods, making air quality monitoring possible in many more locations. Too good to be true? At the current stage of development, unfortunately yes. Measurements by low-cost sensors are often of minor and questionable data quality than the results from official monitoring stations as carried out by EU Member States in accordance with European legislation and International standards. Sensors may become a game changer in monitoring air pollution, traffic-management, personal exposure and health assessment, citizen science and air quality assessment in developing countries. This brochure explains our current understanding of the advantages and disadvantages of sensors. Technological progress will hopefully change the picture of this summary of sensor performance in the next few years. It is also a plea to evaluate and validate sensors with field and laboratory tests in order to understand the meaning of and uncertainties in their signals.JRC.C.5-Air and Climat

Evaluation of the Laboratory Comparison Exercise for SO2, CO, O3, NO and NO2: 13-16 June 2016, Ispra

Eight Laboratories of AQUILA (Network of European Air Quality Reference Laboratories) met for a laboratory comparison exercise in Ispra (IT) to evaluate their proficiency in the analysis of inorganic gaseous pollutants (NO, NO2, SO2, CO and O3). On the basis of criteria adopted, 79.3% of the results reported by AQUILA laboratories were good both in terms of measured values and reported uncertainties. The rest of the results (21.1%) had good measured values, but the reported uncertainties were either too high (17.8%) or too small (2.9%).JRC.C.5-Air and Climat

Results of the European Intercomparison exercise for Receptor Models 2011-2012. Part I

Receptor models are commonly used to identify the sources of ambient particulate matter (PM) in Europe. However, the use of different tools and methodological approaches make it difficult to compare the results of different studies. In order to promote harmonization in this field an intercomparison exercise involving 16 expert groups was organized and evaluated by the JRC with the collaboration of European experts in the field. The test database consisted of 178 PM2.5 speciated samples deriving from two real-world re-arranged DB Participants were asked to scrutinize the database in order to identify, solve and report typical imperfections of real world DBs (missing values, values below detection limits, outliers, unusual uncertainty patterns, etc...). The reported solutions included the number and label of the identified sources, their contribution estimation (SCE) and uncertainty. The exercise was evaluated using a new methodology developed on purpose The majority of the solutions reconstructed the PM mass satisfactorily while the number of sources identified in the different solutions was variable. The correspondence of every source/factor to a source category was checked by comparing its chemical profile and time trend with all the other members of the same category and with reference source profiles, when available. The SCEs of the different solutions were compared with a reference value obtained by robust analysis (standard ISO 5725-5). The acceptability criterion was set to 50% standard uncertainty. More than 90% of the 182 tested profiles passed the preliminary tests and 86% of the assessed source/factor contribution estimations met the acceptability criterion. This result indicates a good general agreement between the performances of the different participants and models.JRC.H.2-Air and Climat

A Quality Assurance and Control Program for PM2.5 and PM10 measurements in European Air Quality Monitoring Networks

To harmonize PM measurements in the European Union, the JRC together with the AQUILA Network of National Air Quality Reference Laboratories organized a PM QA/QC program. From 2006 – 2009, the JRC, equipped with a mobile laboratory, measured in 18 Member States, for a duration of two weeks each, PM10 and PM2.5 in parallel to measurement sites of local networks and to the National Reference Laboratories. The main goals of the project were to find out to which degree PM measurements performed in the Member States agree with the requirements of the relevant EU directive and how correction factors for automatic analyzers were applied.JRC.DDG.H.2-Climate change and air qualit

The Evaluation of the Intercomparison Exercise for SO2, CO, O3, NO and NO2 - April 2008

In April 2008 in Ispra (IT), 8 AQUILA (Network of European Air Quality Reference Laboratories) laboratories met at an intercomparison exercise to evaluate their proficiency in the analysis of inorganic gaseous pollutants covered by European Air Quality Directives (SO2, CO, NO, NO2 and O3). The proficiency evaluation, where each participant¿s bias was compared to two criteria, provides information on the current situation and capabilities to the European Commission and can be used by participants in their quality control system. In terms of criteria imposed by the European Commission, 80% of the results reported by AQUILA laboratories were good both in terms of measured values and reported uncertainties. Another 18% of the results had good measured values, but the reported uncertainties were either too small (7%) or too high (11%). The comparability of results among AQUILA participants is satisfactory for all studied measurement methods.JRC.H.4-Transport and air qualit

The Evaluation of the Intercomparison Exercise for SO2, CO, O3, NO and NO2 - 6 - 9 October 2008

From the 6th to the 9th of October 2008 in Ispra (IT), 7 AQUILA (Network of European Air Quality Reference Laboratories) and 2 laboratories of the World Health Organisations (WHO) Euro-Region met at an intercomparison exercise to evaluate their proficiency in the analysis of inorganic gaseous pollutants covered by European Air Quality Directives (SO2, CO, NO, NO2 and O3). The proficiency evaluation, where each participant¿s bias was compared to two criteria, provides information on the current situation and capabilities to the European Commission and can be used by participants in their quality control system. In terms of criteria imposed by the European Commission, 36% of the results reported by AQUILA laboratories were good both in terms of measured values and reported uncertainties. Another 56% of the results had good measured values, but the reported uncertainties were either too small (21%) or too high (35%). The comparability of results among AQUILA participants is satisfactory for O3, SO2, CO and NO measurement method, but the pollutant NO2 needs further improvements and harmonization programmes.JRC.H.4-Transport and air qualit

Literature review for ODS (Ozone Depleting Substances) measurement methods and data

Stratospheric ozone absorbs most of the sun’s harmful UV radiation. The increased use of human-produced gases such as chlorofluorocarbons (CFCs) has led to a magnified springtime depletion of the protective ozone layer at both Earth’s poles, especially over Antarctica, a phenomenon well known as the ozone hole. The Montreal protocol [1] deals with substances that deplete the ozone layer (ODS) and how to reduce them (Montreal protocol, 1987 and amendments/adjustments). It covers substances with a high ozone depleting potential, CFCs and the 1st generation of CFC replacements (HCFCs). The success of the implementation of the Montreal protocol and amendments has to be demonstrated by the parties (including EU and its Member States [2]), and supported by high quality atmospheric measurements of relevant compounds. Several atmospheric data-sets are available from open-access international data bases, including 7 stations across Europe: (1) Zeppelin, Ny-Ålesund, Norway, (2) Summit, Greenland, Denmark, (3) Mace Head, Ireland, (4) Tacolneston, UK, (5) Jungfraujoch, Switzerland, (6) Monte Cimone, Italy, and (7) Lampedusa (LMP), Italy, but data quality may in some cases be unknown or questionable. High-quality long-term ambient air data are mainly coming from the AGAGE Network (http://agage.mit.edu/ [3]) and NOAA (National Oceanic and Atmospheric Administration). Ref. [3] comprising also European stations from e.g. (I) Ireland (first Agrigole (1978-1983), then Mace Head (from 1987 to present), (II) Switzerland (Jungfraujoch), from 2000 to present, (III) Norway (Ny Ålesund), from 2000 to present, and (IV) Italy (Monte Cimone) from 2002 to present. The trends in ODS concentrations measured in-situ at ground level in Europe are consistent and, similar to the trends observed in the rest of the world (see ref. [4] containing in-situ ground level measurements, flask sampling and satellite observations), especially the downwards trend of CFCs, indicating the success of the Montreal Protocol, in limiting the atmospheric abundances of ODSs [4]. The UNEP/WMO Scientific Assessment of Ozone Depletion from 2014 states [4]: “The success of the Montreal Protocol in limiting the atmospheric abundances of ODSs is now well documented”. This is confirmed by the AGAGE measurement network [3]: “International compliance with the Montreal Protocol is so far resulting in CFC and chlorocarbons abundances comparable to the target level so the Protocol is working”. In contrast, it is of concern that the concentrations of HCFCs and N2O, where the latter one being currently the single most important gas that depletes stratospheric ozone (see e.g. ref. Ravishankara et al., 2009 [15], and discussions in this report), are still increasing.JRC.H.2-Air and Climat

The Evaluation of the Intercomparison Exercise for SO2, CO, O3, NO and NO2 - 13 - 16 October 2008

From the 13th to the 16th of October 2008 in Ispra (IT), 5 AQUILA (Network of European Air Quality Reference Laboratories) and 2 laboratories of the World Health Organisations (WHO) Euro-Region met at an intercomparison exercise to evaluate their proficiency in the analysis of inorganic gaseous pollutants covered by European Air Quality Directives (SO2, CO, NO, NO2 and O3). The proficiency evaluation, where each participant¿s bias was compared to two criteria, provides information on the current situation and capabilities to the European Commission and can be used by participants in their quality control system. In terms of criteria imposed by the European Commission, 44% of the results reported by AQUILA laboratories were good both in terms of measured values and reported uncertainties. Another 56% of the results had good measured values, but the reported uncertainties were either too small (56%) or too high (2%). The comparability of results among AQUILA participants is satisfactory for O3, CO, NO2 and NO measurement method, but the pollutant SO2 needs further improvements and harmonization programmes.JRC.H.4-Transport and air qualit

Results of the First EC/OC Comparison Exercise for EU National Air Quality Reference Laboratories (AQUILA)

The JRC-IES European Reference Laboratory for Air Pollution (ERLAP) has organized an inter-laboratory comparison for the measurement of elemental carbon (EC) and organic carbon (OC) in particulate matter sampled on filters. To this comparison European Union National Reference Laboratories for air quality or delegated organizations have participated, all using instrumentation of the same make (Sunset Laboratories Inc. ). The objectives of this comparison have been to evaluate the performances of participants but also to study the effects of the use of different thermal analysis protocols currently used for analysis. It has been shown – based on z-scores – that all participants using laboratory analyzers are able to meet a 25% expanded uncertainty as a “fitness-for-purpose” criterion for total carbon (TC, as the sum of OC and EC) and OC. For EC this criterion is only met when results are evaluated by specific protocols (NIOSH or EUSAAR_2) separately. Field versions of the analyzer have been found for a number of samples to yield aberrant results.JRC.H.2-Air and Climat