Cooking-Derived Organic Compounds Shape Bacterial Communities on Household Surfaces

Understanding the factors influencing chemical and biological
constituent
accumulation on indoor surfaces is crucial, especially as individuals
spend approximately 90% of their time indoors and frequently interact
with these surfaces. However, the temporal relationships between these
constituents remain unclear, as most field studies have relied on
single-time snapshots and seldom examined the interplay between chemical
and biological dynamics. We conducted a month-long spatiotemporal
field study across 20 households in Hong Kong to investigate the factors
influencing chemical and biological constituents on common indoor
surfaces. Among the 16 household- and occupant-related factors analyzed,
routine oil-based cooking was the primary driver of microbial diversity
and composition on indoor surfaces. Surfaces in kitchens with frequent
cooking exhibited elevated total organic carbon levels, which were
linked to an increased bacterial abundance. A focused analysis of
six kitchens with well-controlled frequencies of oil-based cooking
revealed that cooking-derived organic compounds, particularly alkanes,
promoted bacterial abundance while reducing microbial diversity. Network
analysis further revealed strong interactions between these organic
compounds and bacterial taxa, especially those within the Proteobacteria and Firmicutes phyla. These
findings highlight the impact of routine household activities on indoor
chemical–biological interactions, enhancing our understanding
and informing strategies to improve indoor environments and occupant
well-being.