Effect of formaldehyde exposure on bacterial communities in simulating indoor environments

Abstract

Indoor formaldehyde (CH2O) exceeding the recommended level is a severe threat to human health. Few studies have investigated its effect on indoor surface bacterial communities, affecting habitants' health. This study used 20-L glass containers to mimic the indoor environment with bacterial inputs from human oral respiration. The behavior of bacterial communities responding to CH2O varied among the different CH2O levels. The bacterial community structure significantly changed over time in the 0.054 mg·m−3 CH2O group, which varied from the 0.1 mg·m−3 and 0.25 mg·m−3 CH2O groups. The Chao1 and Shannon index significantly increased in the 0.054 mg·m−3 CH2O group at 6 week, while they remained unchanged in the 0.25 mg·m−3 CH2O group. At 12 week, the Chao1 significantly increased in the 0.25 mg·m−3 CH2O group, while it remained unchanged in the 0.054 mg·m−3 CH2O group. Only a few Operational Taxonomic Units (OTUs) significantly correlated with the CH2O concentration. CH2O-induced OTUs mainly belong to the Proteobacteria and Firmicutes. Furthermore, bacterial communities formed at 6 or 12 weeks differed significantly among different CH2O levels. Functional analysis of bacterial communities showed that inferred genes related to chemical degradation and diseases were the highest in the 0.25 mg·m−3 CH2O group at 12 weeks. The development of nematodes fed with bacteria collected at 12 weeks was applied to evaluate the bacterial community's hazards. This showed significantly impaired growth in the 0.1 mg·m−3 and 0.25 mg·m−3 CH2O groups. These findings confirmed that CH2O concentration and exposure time could affect the indoor bacterial community and formed bacterial communities with a possibly more significant hazard to human health after long-term exposure to high CH2O levels.

Neutralize Bacterial Activity With Anatomical Embalming Solutions

“…Exposure to formaldehyde has an impact on bacterial activity as well. The findings of earlier research demonstrated that exposure to formaldehyde at concentrations of 0.1 and 0.25 resulted in the identification of several species of bacteria, including Clostridia, Bacilli, Sphingobacteria, etc (Guo et al, 2021). The findings of this investigation are consistent with, the greatest formaldehyde concentration measured in the anatomy lab while the covered cadaver was present was higher than the USA-NIOSH suggested ceiling standard of 0.1 ppm but lower than the 0.3 ppm ceiling standard set by the American Conference of Governmental Industrial Hygienists (Ahmed, 2011).…”

“…Additionally, other studies have reported that formaldehyde concentration and exposure time affected the bacterial community. At 0.054 mg/m 3 the bacterial community composition changed significantly over time (Guo et al, 2021).…”

“…Therefore abatement or targeted reduction strategies should be implemented when formaldehyde cannot be eliminated or replaced (Cammalleri et al, 2022). The effects of formaldehyde on airborne microbes are yet known that shown the indoor bacterial population (using glass containers as mimic) potentially creating bacterial communities that pose a greater risk to human health over time during formaldehyde exposure (Guo et al, 2021). However, it is still unknown how formaldehyde exposure affects airborne bacteria predominance and whether specific formaldehyde levels are safe for people whilst decreasing bacterial presence.…”

Indoor heterogeneous photochemistry of molds and their contribution to HONO formation

“…This correlation is probably due to the use of sulfate, nitrate, and carbonate (transformed from these gases) as the nutrients by the viable microbes. 25 In a recent study by Guo et al, 26 the effect of different formaldehyde levels, a harmful indoor VOC emitted by various indoor surfaces, on indoor bacterial communities was established. This study has shown the interaction between formaldehyde levels and indoor bacteria and gave new insight for future studies on the interaction between indoor pollutants and microbial species.…”