English Abstract In this report monitoring results of the National Air
Quality Monitoring Network are presented covering the calendar year 1989 and
the period April 1988 - april 1989. The components reported are SO2, black
smoke, NO2, NOx (=NO2 + NO), NO, O3, OX (=NO2 + O3) and CO. In 1989 several
summer smog episodes occurred which contributed to exceedence of Dutch air
quality limit values for NO2 on a few staitons. However exceedence of the
Dutch draft limit values for O3 were not detected. At a few stations the
limit values for black smoke were exceeded and at one station the maximal
allowable hour value was exceeded once caused by an incidental polluting
activity. Guide values for SO2 and NO2 were exceeded at 6% and 80% resp.
of the total number of stations. The draft guide value for O3 was exceeded
at all stations, ranging from 3 to 88 times.