Indoor surfaces can act as massive sponges for harmful chemicals

Interior surfaces have an unexpected ability to absorb and have harmful chemical compounds that can threaten human health as long as a year, according to researchers in air chemistry from the University of California in Irvine.

In an article published in Proceedings of the National Academy of SciencesUC IRVINE scientists quantify how various interior surfaces absorb volatile organic compounds, which can lead to unhealthy conditions for people and animals when they are inhaled or absorbed by skin contact.

There are many VOC sources, such as cooking, cleaning spraying, personal care and other consumer products. Significant additional contributors include tobacco smoke, and more and more air pollution caused by forest fires. The researchers note that health risks come from the inhalation of compounds when they “turn off the gas” from surfaces and by skin absorption when contaminated surfaces are affected.

In the spring of 2022, co-author Jonathan Abbatt, professor of chemistry at the University of Toronto, led the chemical assessment of surfaces and air study, which used simulation chambers of the National Institute of Standards and Technology Net-Zero Energy Residential Test Facility. The contaminants were injected into a structure imitating a family environment, with typical building materials. The research team used mass spectrometry instruments to follow the movement and persistence of VOCs in the controlled inner environment.

“Scientists of the Air Chemistry Research Community have long since known that many interior contaminants can be absorbed by interior surfaces, but the size of interior surface tanks inside houses and buildings had not been established,” said Manabu Shiraiwa, professor of chemistry UC Irvine, who was responsible for modeling observations and is a corresponding author on the corresponding author corresponding on the corresponding author on the corresponding author on the author corresponding to the corresponding author on the corresponding author of the UC Irvine PNA paper.

“Our modeling found that surfaces inside houses have a much larger size to absorb and contain chemicals than that previously.

Before this study, thin organic films with nanometric thickness were considered as main surface tanks. However, this work proves that permeable and porous materials such as painted surfaces, cement and wood are probably the main surface tanks in a house.

“This discovery has important implications for human health,” said Shiraiwa. “This means that people can be exposed to harmful chemicals long after their initial introduction in interior spaces, and the compounds can then be released into the air or transferred to humans by direct contact with contaminated surfaces.”

He added: “This result has a significant impact on our understanding of the fate of the voc and human exposure in interior environments. With such a large part of partitioning, organic contaminants will have much longer interior residence time than previously expected.”

Research explains why some odors and contaminants persist inside even after the abolition of their sources. For example, it provides scientific evidence for which tobacco smoke odors linger in parts long after stopping smoking: residual compounds, called “third -hand smoke”, slowly share in the air of surface tanks.

The results suggest that regular ventilation can be insufficient to eliminate many interior contaminants. Physical cleaning activities such as vacuum cleaner, cleaning and sprinkling are necessary to effectively remove compounds with high partition coefficients from surface tanks.