The Swedish Environmental Research Institute (IVL) has mapped air pollution levels of sulphur dioxide (SO₂), nitrogen dioxide (NO₂) and volatile organic compounds (VOC) in Tallinn. This project is a part of an Air Quality Management Project in Tallinn, Estonia, financially supported by the Swedish International Development Co-operation Agency (Sida). The Estonian party is the Environment Department, Tallinn City Government and the Swedish party is Conexor Sensus AB.

The main purpose of the measurement campaign was to generate data with high spatial resolution. The current databases, based on traditional measurement techniques contain high time resolution data from a few locations. An additional purpose of the campaign was to introduce a cost-effective air pollutant measurement technique in Estonia, demonstrating its potential to rapidly create an adequate background material for decision-makers. The two measurement databases will together provide a good basis for future validation of dispersion model results.

The measurements were carried out using diffusive samplers and were organised as a total of 12 monthly campaigns during the period from April 1996 to January 1998. Monthly samples of SO₂ and NO₂ were collected during all campaigns, while four weekly samples of VOC were collected during each of four of the campaigns.

The siting of measurement stations was based on a classification into four types according to exposure to road vehicle emissions and street ventilation conditions. The measurements were made at urban as well as at background sites. The Environment Department and IVL designed the station network in co-operation.

All practical matters related to the sampling have been accomplished by the Environment Department, Tallinn City Government. All chemical analysis of samples has been made at IVL.