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

摘要

Chemicals resulting from the use of cleaning products has been suspected as one of the causes behind indoor air problems. Exposure to these substances can be harmful for occupants and may have selective impact on the indoor microbiome. Therefore, we studied the effects of cleaning practises and chemicals on indoor microbiome and air quality in two school buildings and one day care center. Our research included microbial assessment from settled dust and indoor air, and the chemical composition of indoor air was observed with chemical assessment of volatile organic compounds (VOCs) and carbonyl compounds. The field study consisted of three research periods: 1. "Normal" cleaning where practises and products were the ones that are used daily. 2. Cleaning intervention where only water and microfiber cloths were used in cleaning of the surfaces. 3. Returning to the original cleaning practises. We did not observe any consistent trend of the impact of cleaning intervention on microbial levels from settled dust. None of the microbial groups that were measured were consistently lower of higher during the cleaning intervention compared to baseline. However, levels of viable bacteria assessed from indoor air were consistently higher during the intervention in both schools and the day care center regardless of changes in the levels of outdoor microbes. Overall concentrations of chemical compounds were on a low level (<50 pg/m3 for VOCs, <21 u.g/m3 for carbonyls) during the field study. Contrary to expectations, total concentrations of VOCs (TVOC) were slightly higher during the cleaning intervention. Nonetheless, we did not find any consistent changes in the individual compounds that could connect the increase of TVOC concentrations directly to the cleaning intervention.