Cleaning chemicals and practices : Effects on air quality and indoor microbiota

Chemical residues from the use of cleaning products have been suspected as one of the causes behind indoor air adverse health effects. Presence of chemicals may also have selective impact on the indoor microbiome. Therefore, we implemented a two-year study in 13 schools and 1 day care center in Helsinki Metropolitan area. The aim of the study was to clarify how cleaning chemicals are used in practice as well as the effects of cleaning chemicals and biocides on measured indoor air quality. We studied the indoor microbiota with different sampling methods both in laboratory studies and field measurements. We did not detect any consistent trends of the impact of cleaning intervention - water only cleaning versus regular cleaning agent use - within the measured microbial, chemical and particle parameters. Cleaning with water only did not consistently increase microbial levels and the efficiency of the cleaning was the same. On the other hand, indoor air concentrations of chemical compounds did not decrease during the water only cleaning in this exploratory study.