TL;DR: Researchers have detected toxic substances in 81 pairs of headphones and earbuds from major brands, including Bose, Panasonic, Samsung, and Sennheiser. The substances have been linked to cancer, neurodevelopmental problems, and feminization in males. Materials with other harmful effects were also detected in trace amounts.
According to The Guardian, the TOX-Free Project tested 81 pairs of in-ear and over-ear headphones available from Shein, Temu, and retailers in the Czech Republic, Slovakia, Hungary, Slovenia, and Austria. Of the samples tested, 98% contained bisphenol A and more than three-quarters contained its substitute, bisphenol S.
Prior studies indicated that the synthetic chemicals, which are used to harden plastic, mimic the effect of estrogen in organisms, potentially leading to cancer, early onset of puberty in females, and feminization in males. Although the materials are solid, studies also suggest that they can penetrate the skin through sweat, especially during exercise.
Although the study does not mention Apple products, such as AirPods, bisphenol appears on the Cupertino giant's list of regulated chemicals, indicating that the company is aware of the risk. The researchers also detected minor quantities of phthalates, which can reduce fertility, chlorinated paraffins, which can damage the kidneys, and potentially harmful brominated and organophosphate flame retardants.
The EU-funded TOX-Free project aims to enhance the detection and awareness of drugs, pesticides, and chemical pollutants in everyday products. Partnering with organizations in Italy, Germany, the Czech Republic, Austria, and other countries, the project aims to discover new methods of measuring the effects of chemicals on humans using nanotechnology. According to TOX-Free's research, virtual mirror cells can turn the electrophysiological activity of neurons and cardiomyocytes into light signals, enabling easy and accurate monitoring of neuro- and cardiotoxicity.
Drugs, air pollutants, nanoplastics, and pesticides are the group's primary focus, akin to ongoing concerns regarding forever chemicals, poly- and perfluoroalkyl substances (commonly known as PFAS), and other pollutants. However, TOX-Free directed its attention toward headphones because they have become essential for everyday life, and people increasingly wear them for extended periods. Although substances such as bisphenol A and S have no short-term health risks, repeated, long-term exposure might be harmful, especially for teenagers.
As headphones become more advanced, certain risks have also become associated with technologies such as noise-canceling and Bluetooth-enabled plug-and-play. Last year, researchers discovered that excessive use of noise-canceling headphones can lead to auditory processing disorder, which impacts the brain's ability to interpret sounds and speech. Last month, security researchers also uncovered vulnerabilities in Google Fast Pair that could enable hackers to take control of headphones, eavesdrop on conversations, and track their locations.