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 stations. 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.