A novel report concerning air quality measurements is finished. Urban air quality measurements were conducted near the city ports in three harbour cities around the Baltic Sea region: Tricity in Poland, Gothenburg in Sweden and St. Petersburg in Russia. Measured air quality components included NOx, SOx, CO, O3, PM10, and PM2.5. The measurements of these components in the pilot cities were investigated against the reference methods. The measurement systems and the quality management systems were also audited. The used methods, results and conclusions of these investigations are presented in the report.