The Role of the European Commission in the Maintenance of Air Quality Standards

Abstract

WE DESCRIBE INTERCOMPARISON RESULTS OBTAINED IN THE FRAMEWORK OF THE EC DIREC- TIVE 779/80 CEE ON SO2, BLACK SMOKE (BS) AND TOTAL SUSPENDED PARTICULATES (TSP).CALIBRATIONS AND MEASURING METHODS USED IN NATIONAL LABORATORIES WERE COMPARED TO THE REFERENCE METHODS LAID DOWN IN THE DIRECTIVE. TO THIS END, STANDARDS OF AIR-SO2 MIXTURES AT 40 AND 190 PPB SO2, BS AND TSP FILTERS AT DIFFERENT DARK- NESS LEVEL AND LOAD HAVE BEEN CIRCULATED AMONG NUMEROUS LABORATORIES AND SOME MEASURING STATIONS. ON THE AVERAGE, 78% OF SO2 MEASUREMENTS CARRIED OUT IN LABORATORIES AND 21% IN NETWORK STATIONS WERE COMPARABLE WITH THE IMPROVED RE- FERENCE METHOD (TETRACHLORO-MERCURATE PARAROSANILINE). WERE THE DEVIATIONS EX- CEED THE TOLERANCE LIMIT OF +-6%, THIS WAS RATHER BECAUSE OF INAPPROPRIATE HAN- DLING OF THE CALIBRATION THAN BECAUSE OF POSSIBLE SHORTCOMINGS OF THE DIFFERENT METHODS THEMSELVES. IN CONTRAST, FOR BS, LARGEST DEVIATIONS WERE CAUSED BY DIFFERENCES IN CONFIGURATIONS OF FILTER/REFLECTOMETER AND OF THE CONVERSION CUR-VES, FOR TSP BY VARYNG THE TYPE OF FILTERS, BALANCE SENSIBILITY AND CONDITIONINGPROCEDURES BEFORE WEGHING.TO AVOID ANY DISCRIMINATORY STRINGENCY FOR THE DIREC- TIVE, THERE IS THE NEED, FOR THE MEMBER STATES, TO DEFINE MORE STRINGENT REFE- RENCE METHODS AND IMPLEMENT QUALITY ASSURANCE PROGRAMMES, ESPECIALLY IN THE NETWORKS.NA-NOT AVAILABL