engleski

Levels of Nitrogen Dioxide in the Zagreb Air

Surveillance of NO2 in Zagreb has started in 1994 at 5 measuring sites. This paper presents the levels and trends of NO2 annual mean values for the period between 1994 and 1998. The obtained data are compared with the recommended and limit values according to the Law on Air Quality Protection in Croatia and the Ordinance on Recommended and Limit Air Quality Values. For the last 5 years, ever since the measurement commenced, the concentration levels of NO2 in Zagreb have remained above the recommended values and below limit values at all measuring sites, indicating that the air is moderately polluted. This paper also shows the variations of monthly mean values through 1998 at all sites. The levels of NO2 in the northern part of Zagreb were measured at two different distances from traffic. At the same site, daily variations in the levels were measured near the road and presented as hourly averages for workdays and weekends in winter and in summer reflecting activity pattern of emission sources.

air quality; limit values; recommended values; surveillance

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