Toasters top list of home appliances emitting trillions of ultrafine particles, study finds

A study by researchers from Pusan National University in South Korea warns that common small home appliances could be emitting trillions of ultrafine particles containing heavy metals. The researchers say these particles can penetrate deep into the lungs and potentially enter the bloodstream, with links to asthma, heart disease, high blood pressure, diabetes, cancer and dementia. Toasters were identified as the worst offenders, capable of emitting up to 1.73 trillion ultrafine particles per minute.

The assessment tested three types of devices — air fryers, toasters and hairdryers — and measured the quantity of ultrafine particles emitted, as well as the chemical composition of the metals in the particles. The researchers defined ultrafine particles as those smaller than 100 nanometers in diameter and used a simulation model to understand how such particles would deposit along human airways, helping identify who might be most susceptible.

The results showed that most devices released substantial UFPs, with emissions rising at higher operating temperatures. At a 200°C setting, the air fryer produced about 135 billion ultrafine particles per minute. In some hairdryer models, emissions reached roughly 100 billion per minute. The heavy metals detected included copper, iron, aluminum, silver and titanium, likely originating from the device coils and motors.

The researchers cautioned that although the study did not directly measure health outcomes, prior research links ultrafine particle exposure to several conditions, and the particles tend to deposit predominantly in the alveolar region of the lungs. They emphasized that children may be at higher risk due to smaller airways. Lead author Professor Changhyuk Kim called for emission-aware appliance design and age-specific indoor air quality guidelines, noting that reducing ultrafine particle emissions could improve indoor environments and reduce long-term exposure, especially for young children.

The study adds to a broader body of work highlighting indoor air pollution from everyday products. Earlier this year, Purdue University researchers warned that products such as air fresheners, wax melts and household cleaners can create plumes of indoor air pollution. Experts stressed that many consumer products release volatile compounds that can contribute to poor indoor air quality and health risks.

Publication details: The study was published in the Journal of Hazardous Materials.