α-Pinene, 3-carene and d-limonene in indoor air of Polish apartments: the impact on air quality and human exposure.

Monoterpenes are among most ubiquitous volatile organic compounds (VOCs) to be detected in indoor air. Since the quality of indoor air is considered important for inhabitants' well-being, the present study aimed at investigating impact of human activity on levels of selected monoterpenes applying passive sampling technique followed by thermal desorption and gas chromatography coupled mass spectrometry. One of the objectives of the present work was to identify and characterize main emission sources as well as to investigate relationship between selected monoterpenes in indoor air. Concentration levels obtained for studied monoterpenes varied from 3 μg m(-3) for 3-carene to 1261 μg m(-3) for d-limonene. D-limonene was reported the most abundant of studied monoterpenes in indoor air. The strong correlation observed between monoterpenes suggests that studied compounds originate from same emission sources, while the I/O >1 proves the strong contribution of endogenous emission sources. The in-depth study of day-night fluctuations in concentrations of monoterpenes lead to the conclusion that human presence and specific pattern of behavior strongly influences presence and concentrations of VOCs in indoor environment. The evaluation of human exposure to selected monoterpenes via inhalation of air revealed that infants, toddlers and young children were the highly exposed individuals.