Indoor dust mimics sex hormones such as estrogen and testosterone in human cells, according to a new study from Harvard T.H. Chan School of Public Health. The dust contains a stew of dozens of chemicals that migrate out of furnishings and that can interfere with sperm counts, fertility, successful birth, and the timing of puberty and menopause.
“We know from decades of research that these hormone-disrupting chemicals are prevalent in our bodies and that our exposures to them are associated with infertility, stunted development, thyroid disease, obesity, and diabetes,” said lead author Anna Young, a postdoctoral researcher in the Department of Environmental Health. “This study adds new evidence incriminating indoor spaces in buildings as a channel through which chemicals from furnishings interfere with our hormones.”
Joseph Allen, associate professor of exposure assessment science and senior author, noted, “These chemicals are found in dust in all types of indoor spaces — in homes, offices, schools, airplanes, cars, and more.” According to the Environmental Protection Agency, adults ingest about 20 milligrams of indoor dust every day.
The study was published April 14, 2021, in Environmental Health Perspectives.
The researchers collected dust samples from 46 rooms—including common spaces, offices, and classrooms—at a U.S. university during January to March 2019. In the lab, they exposed human cells to the dust samples, and measured the cells’ hormonal activities in relation to concentrations of flame-retardant and stain-repellent chemicals, including per- and polyfluoroalkyl substances (PFASs), organophosphate esters (OPEs), and polybrominated diphenyl ethers (PBDEs).
The concentrations of these chemicals in the dust significantly influenced the extent to which the dust mimicked hormones, the researchers found. In addition, hormonal activity occurred with every single dust sample. “This wasn’t a one-off result,” Young said.
She added, “Nobody thinks dust is ‘clean,’ but it’s shocking to process that dust is hormonally active and interferes with the function of our sex hormones. We observed hormonal effects in human cells with as little as four micrograms of dust, so it doesn’t take a lot of dust either.”
Producing furnishings that don’t contain unnecessary flame retardants or stain repellents can help reduce levels of hormone-disrupting chemicals in dust in buildings, Young said. “We just need healthier materials to become the norm, not the exception,” she said.