Human chemical signature – investigation on the influence of human presence and selected activities on concentrations of airborne constituents
Available indoor air quality (IAQ) studies on tobacco- and nicotine-containing potentially reduced-risk products (PRRPs), such as electrically heated tobacco products and e-cigarettes, demonstrate substantial reduction of environmental emissions compared with cigarette smoking. The IAQ studies on these products apply common IAQ markers (carbonyls, volatile organic compounds [VOC], particulate matter) together with specific tracers, such as nicotine. All indoor environments naturally contain certain levels of the general IAQ markers, while they are usually free of the specific tracers. These present a particular challenge for the assessment of the environmental aerosols generated by potential RRPs. Thus, special attention should be taken to assess the qualitative and quantitative impact of additional pollution sources (e.g. the study participants). In addition, for studies in real-life environments, the impact of different daily life and recreational activities must be considered. To better assess the influence of these parameters on the concentrations of selected air constituents, an exploratory study was performed under simulated residential conditions in an environmentally controlled exposure room. The human subjects either remained for a certain time in the exposure room, or participated in predefined scripted activities (drinking wine, participating in sporting activities, using cosmetics, and cooking). Each activity was assessed separately using our analytical platform and exposure room under controlled environmental conditions. The results showed that prolonged human presence and activities indoors led to an increase in the levels of selected VOCs, cyclic volatile methyl siloxanes and formaldehyde. These constituents were found in higher amounts above the background level when the study participants remained for some time in the exposure room or participated in certain activities. The learnings were applied to optimize the experimental set-up of further studies aiming to assess the IAQ impact of using RRPs in real-life settings.