Researchers discover pollution risks in buildings – ScienceDaily

They rarely think of the air they breathe at home.

In a new study on indoor air quality, a team of WSU researchers discovered surprisingly high levels of pollutants, including formaldehyde and possibly mercury, in carefully monitored homes. These pollutants vary during the day and increase with temperature. Their study, led by Tom Jobson, professor in the Department of Civil and Environmental Engineering and graduate student Yibo Huangfu, was published in the newspaper, Building and environment.

Researchers know that indoor and outdoor air pollution has a significant impact on people's health, including their heart, lungs, brain and health. neurological. However, as the government increasingly regulates outdoor air pollution over the last 40 years, there is little air regulation in homes. Building laws generally require that houses be structurally sound and that people be comfortable – with minimal impact on odors and humidity.

"People think that air pollution is an outdoor problem, but they do not recognize that they are exposing themselves to much higher emission rates at home," said Jobson.

These emissions come from different sources, such as building materials, furniture, household chemicals and human activities such as cooking.

One of the ways to eliminate harmful chemicals is to ventilate the outside. But, worried about climate change and eager to reduce energy consumption, builders are trying to make homes more watertight, which could inadvertently compound the problem.

In their study, the researchers examined a variety of homes, meant to reflect the typical home and age styles of the United States. They found that formaldehyde levels increased with temperature inside, between three and five parts per billion the temperature rose to a degree Celsius.

"When a house heats up, there is a lot more formaldehyde in the house, the materials are hotter and emit a lot more gas," Jobson said.

The work shows how heat waves and regional climate change could affect the quality of indoor air in the future.

"When people go through a hot summer without air conditioning, they will be exposed to much higher concentrations of pollutants in the interior," he said.

The researchers also found that pollution levels varied throughout the day: they were highest in the afternoons and lows early in the morning. Until now, manufacturers and builders have badumed that pollutants remain the same throughout the day, while taking into account the emissions of their materials, so as not to have a real idea of ​​how much pollution that people are exposed to inside, he said.

Researchers were also surprised to find in a house that gypsum board emitted high levels of formaldehyde and possibly mercury when heated. This house, built in the early 1970s, had radiant heating in its ceiling, which was a popular heating system at that time.

After discovering high levels of formaldehyde in the home, the researchers suspected the plasterboard ceiling in the house. About half of the gypsum used in homes as drywall is made from waste from the coal industry. They took out a room from the house, heated it in their lab and measured high levels of formaldehyde – up to 159 parts per billion.

Household exposure to formaldehyde is not regulated in the United States, but the US Agency for Toxic Substances and Disease Registry, part of the Centers for Disease Control, has set a target of eight parts per billion minimal risk.

"Exposure to these chemicals has an impact on people's ability to think and learn," Jobson said. "It's important that people are more aware of the risk – opening a window is a good thing."

Researchers plan to continue to look for ways to reduce exposure to indoor air pollutants, including the use of green building materials.

"We need to find a balance between building energy efficient homes and protecting our health and cognitive function," he said.

The work was funded by the US Environmental Protection Agency.