Living with VOCs: Understanding indoor emissions and their implications beyond four walls

In developed countries, people spend nearly 90% of their time indoors, where activities such as cooking and cleaning are significant sources of air pollution, with consequent impacts on occupant health. Volatile organic compounds (VOCs), emitted indoors, can also escape into the urban outdoor environment and contribute to secondary pollution, e.g. via production of ozone and particulate matter formation. This comes at a time when successful regulation has led to gradual decreases in emission from some traditional emission sources such as traffic. Despite their importance, VOC from indoor sources remain understudied, with limited understanding of their emission patterns and broader environmental impacts. In this work, we used selected ion flow tube mass spectrometry (SIFT-MS) to examine VOC emissions from common indoor activities under controlled laboratory and semi-realistic domestic conditions. The speciated chemical signatures and emission rates derived from real-time measurements provide valuable insights into the sources and dynamics of these indoor emissions and help identify the tracer molecules (like nonanal, chloroform, carbon tetrachloride, nonane, etc) that can also be used to assess the contribution of indoor activities to the urban ambient air. These findings provide a valuable framework for understanding and designing comprehensive intervention strategies to address both indoor and outdoor air quality challenges.