The monitoring of nitrogen dioxide in Madrid using passive samplers
The recommendations of the EC Commission in the frame of NO(2) network design have been applied to an air quality survey in Madrid, performed by means of mobile measurements and 192 passive diffusion samplers uniformly distributed over the agglomeration. In order to evaluate the distribution of the urban NO(2) pollution over the year, the tubes were sampled for two-week periods in summer 1990 and winter 1990-91. Iso-concentration curves from 10 to 10 microgram NO(2)/m3 sections have been elaborated from a three dimensional representation of the concentration versus the coordinates of the sites. The areas of the iso-curves gave evidence of higher average concentration in winter, but peaks higher than 75 microgram NO(2)/m3 were only recorded in summer, because of increased photochemical activity. The values have been compared to the limit value of the Directive reported to the annual average for the passive measurements and to the 99 percentile for the mobile measurements. The results showed, for a 8/10 days pollution episode, the breaching of the Directive's limit value (230 microgram NO(2)/m3) at the kerbside of roads carrying heavy traffic. Even if no background site (passive samplers) showed a breach of the annual average limit value (80 microgram NO(2)/m3), 11 sites at risk, i.e. between 60 and 80 micrograms/m3, were identified. Although the location of the Madrid network stations, mainly traffic orientated, are in agreement with the criterion of measuring maximum pollution, it is not certain whether some of the existing stations in this risk area comply with the exposure criterion. A survey at the airport area, where the limit guide value was exceeded, and in one green area where a minimum was measured, would also be advisable.
Bibliographic Reference: EUR 14175 FR (1991) 70 pp., FS, free of charge
Availability: Available from Joint Research Centre, Public Relations Office, I-21020 Ispra (Va.) (IT)
Record Number: 199210606 / Last updated on: 1994-12-02
Original language: fr
Available languages: fr