How our homes absorb VOCs has ‘significant implications

New research has found that the walls, furniture and surfaces inside our homes play a much bigger role in trapping and holding onto pollutants than previously understood.

The University of California – Irvine study was conducted in a carefully monitored test house to explore what happens when volatile organic compounds (VOCs) are released indoors.

Scientists injected controlled amounts of VOCs into the air of the house, then tracked how quickly the chemicals disappeared from the air and where they went.

They found that instead of simply vanishing outdoors through ventilation, a huge amount of the chemicals soaked into the surfaces of the house itself.

The idea that surfaces can ‘store’ pollutants isn’t new but this research suggests that this happens to a much greater extent than previously thought.

Instead of just thin films of organic material coating indoor surfaces it was found that, at the microscopic level, porous materials like paint, wood and concrete act like giant sponges.

According to the study, the amount of pollutants absorbed by surfaces in the test house was equivalent to coatings thousands of times thicker than those thin films.

Manabu Shiraiwa, UC Irvine professor of chemistry, who was responsible for modeling observations and is a corresponding author on the paper, said: ‘Scientists in the air chemistry research community have known for a long time that many indoor contaminants can be absorbed by indoor surfaces, but the size of indoor surface reservoirs inside homes and buildings had not been established.

‘Our modeling found that surfaces inside homes have a much greater size to absorb and hold chemicals than previously realized. We can think of these surfaces as massive chemical sponges that soak up VOCs.’

Furthermore, once absorbed, these pollutants can slowly leak back into the air over hours, days or even years, long after the original source is gone.

Shiraiwa added: ‘This discovery has significant implications for human health. It means people can be exposed to harmful chemicals long after their initial introduction into indoor spaces, and compounds can later be released back into the air or transferred to humans through direct contact with contaminated surfaces.

‘This result significantly impacts our understanding of VOC fate and human exposure in indoor environments. With such a large partitioning capacity, organic contaminants will have much longer indoor residence times than previously predicted.’

source : How our homes absorb VOCs has ‘significant implications