Benzene, toluene, formaldexyde and p-xylene are measured in Riga by DOAS stations (see Table 1 ) in different places.

Increased pollution of air with hydrocarbons (benzene, toluene) is observed in harbour region of Riga, where number of enterprises is connected with oil transport. The DOAS station of Riga City Council is measuring pollution in Sarkandaugava region of Riga more than year. In most of cases when wind is blowing from enterprise "ManTess" where oil tranship occurred, characteristic peaks of benzene and toluene are observed.