In the first half of 2017, different complaints were received in the Basque Government (Spain) regarding “bad smells” in the municipality of Durango (Spain). The Vice-Ministry of Environment of the Basque Government carried out a campaign to measure and control the air quality of Durango with a GC-MS mobile unit. One of the work areas was to carry out several Volatile Organic Compounds (VOC) characterization campaigns through a mobile unit provided with a GC-MS chromatography equipment between October 2017 and December 2018, given that the VOC analysis showed values of Benzene that were higher than those ranges measured in other areas of the Basque Autonomous Community (Spain), and very close to the limit values in air quality.

Throughout the study of characterization of the pollutants that possibly generated the discomfort of smell, abnormal values of benzene, toluene, styrene and xylene (BTSX) were detected. Subsequently, after conducting a research, the sources of origin of the BTSX were found in two foundries in the area; both foundries used a lost foam process for the elaboration of their pieces. Thanks to an analysis on the quality of the air and on the emissions (chimney) of these foundries, it was concluded that in both cases, the lost foam process was the cause for the high BTSX rates in the area.