Assessment of VOCs concentrations in Spanish dwellings: Acetone, toluene, xylene, alpha-pinene and limonene

Abstract

The presence of certain Volatile Organic Compounds (VOCs) indoors represents a potential concern for occupant health, especially in dwellings with limited ventilation. In this context, the study analyzed the presence of five health-related VOCs (Acetone, Toluene, Xylene, α-Pinene, and Limonene) in Spanish dwellings. This research addresses a significant data gap, as Spain did not participate in similar European indoor air quality campaigns (INDEX or IEA-EBC Annex 68 projects). The main objective of the study was to characterize the indoor air quality in these dwellings and compare the findings with comparable data. The concentrations of these pollutants were measured in different rooms of 29 occupied dwellings located in a continental climate in Spain during the winter period, using solid-phase microextraction coupled with gas chromatography with a flame ionization detector (SPME-GC-FID), under typical winter conditions of reduced ventilation. The results revealed the widespread presence of some compounds in most dwellings, while others were only occasionally detected, associated with specific household activities. The main sources identified were cleaning products, cosmetics, and furnishings. Acetone and Limonene showed the highest concentrations, consistent with their frequent household use, while Toluene and Xylene demonstrated lower levels consistent with the decline in their traditional sources (paints, solvents, tobacco); α-Pinene, meanwhile, was detected at very low levels, possibly due to recent changes in household product formulations. These findings emphasise the importance of ventilation, especially during winter, in reducing VOC accumulation and highlight the need to broaden the regulatory focus on indoor air quality beyond carbon dioxide.