Are Small Electric Appliances Contaminating the Air You Breathe with Heavy Metals?

• Researchers targeted appliance features known to generate airborne particles during routine use — Heating coils and brushed direct current motors were selected based on prior aerosol science showing both release particles under normal operating conditions. Heating coils reach high temperatures through electrical resistance, a process that promotes evaporation and condensation of metal components.

Brushed motors rely on constant physical contact between brushes and rotating parts, producing friction and electrical sparking that wear down metal surfaces. These processes occur during everyday use and do not require malfunction or misuse.

• Emission patterns differed sharply depending on appliance design and particle size range — Hair dryers equipped with brushed motors produced large numbers of UFPs, typically smaller than 25 nanometers.

In contrast, air fryers and toasters relying mainly on heating coils generated slightly larger UFPs, generally between 25 and 100 nanometers. Although larger, these particles still behave very differently from visible dust or soot and remain readily inhalable.

• Brushless motor designs released substantially fewer UFPs — When researchers compared brushed hair dryers to brushless models, emissions from brushless designs were at least 1.4 times lower under similar operating conditions. This difference helped isolate the role of mechanical contact and sparking in particle generation and showed that design choices within the same appliance category meaningfully influence indoor air pollution.

• Chemical analysis revealed heavy metals originating from appliance components — Many of the collected UFPs contained metals commonly used in appliance construction. Copper appeared frequently, consistent with its role in motor windings and electrical contacts. Iron and aluminum were also detected, reflecting structural components and heating elements.

Silver and titanium, both used in certain coatings and alloys for heat resistance and durability, were identified as well. These metals were present as ultrafine airborne particles rather than bulk fragments, making them capable of entering the respiratory system during normal appliance use.

• Higher temperatures and typical usage patterns increased exposure potential — Particle emissions increased at higher heat settings, which fits with how metals heat up, wear down, and release material over time. Real-world exposure also depends on how people actually use these appliances day to day.

Hair dryers often operate close to the face and upper body, while cooking appliances are frequently used in confined kitchen spaces with limited ventilation. Repeated daily use under these conditions increases the likelihood that particles remain suspended long enough to be inhaled.

• UFPs preferentially deposited deep in the lungs — Using a model that tracks how particles move through the airways, researchers found that most UFPs traveled deep into the lungs and settled in the alveoli, the tiny air sacs where oxygen enters the bloodstream.

At this size, the movement of the particles was driven by diffusion rather than gravity, which lets the smallest particles lodge more easily in delicate lung tissue than larger ones, even when standard air quality readings suggest exposure is low.

• Children experienced a higher internal lung burden than adults — The modeling also revealed that children ended up with more particles settling in their lungs relative to lung size, mainly because their airways are smaller and the way they breathe differs from adults.

Even after accounting for body weight, children still carried a higher particle load in lung tissue. This means the same indoor air can lead to a much higher internal exposure for children, especially in homes where these appliances are used several times a day.

• The findings point to broader design and policy implications — By showing how routine household devices release metal-containing UFPs under normal use, the research highlights gaps in how indoor air risks are currently assessed and managed.

"Our study emphasizes the need for emission-aware electric appliance design and age-specific indoor air quality guidelines. In the long term, reducing UFP emissions from everyday devices will contribute to healthier indoor environments and lower chronic exposure risks, particularly for young children, than current status.

Moreover, this framework can be extended to other consumer products, guiding future innovations toward human health protection," said Changhyuk Kim, Ph.D., lead author and professor at PNU.⁴

• Respiratory inflammation and reduced lung function — UFPs deposited deep in your lungs can trigger inflammation of airways and lung tissue. Persistent inflammatory responses contribute to conditions like asthma, chronic bronchitis, and many cases of reduced lung capacity.

• Oxidative stress and cellular damage — Once inside the body, heavy metals generate reactive oxygen species (ROS). ROS are highly reactive molecules that damage cellular components, including lipids, proteins, and DNA. This oxidative burden overwhelms your antioxidant defenses and contributes to chronic inflammatory signaling and tissue injury.

• Cardiovascular stress and dysfunction — UFPs and heavy metals in circulating blood are associated with changes in vascular function, including endothelial dysfunction (the lining of your blood vessels). These changes are linked to increased blood pressure and a greater risk of ischemic heart disease, heart rhythm abnormalities, and vascular inflammation that underlies many cardiovascular conditions.

• Neurotoxicity and brain effects — Certain metals, such as copper, can reach the brain by crossing the blood-brain barrier. Within nervous system tissue, they promote neuroinflammation and oxidative stress, which are associated with impaired motor function, particularly in children, as well as increased susceptibility to neurodegenerative processes over time.

• Disruption of cellular regulation and repair — Many heavy metals disrupt key biochemical pathways that regulate cell growth, survival, and programmed cell death (apoptosis). For example, metals can block antioxidant defenses and disrupt key proteins inside cells, weakening normal repair processes and increasing the risk of abnormal cell behavior.

• Increased carcinogenic risk — Persistent oxidative stress and DNA damage from heavy metal exposure drive mutations that play a direct role in cancer development. Chronic inflammation and interference with normal cell division add to this risk, creating conditions that allow damaged cells to survive and multiply over time.

• Impaired development — Because children's organs are still developing and their detox systems are not fully mature, they clear inhaled metals less efficiently. When exposure occurs during key stages of lung and brain development, more particles accumulate relative to body size. This higher internal load increases the likelihood that inhaled metals affect breathing, circulation, and long-term health.

• Metabolic and autonomic disruption — Evidence links particle exposure to insulin resistance and metabolic dysregulation. Inhaled particles also interact with autonomic nervous system pathways, which can influence heart rate variability and stress responses, further contributing to chronic disease risk.

1. Support liver function with adequate choline intake — Your liver is the primary organ responsible for processing heavy metals and exporting them into bile so they can be eliminated through the intestines. When choline intake is insufficient, fat accumulates in the liver, impairing this detox function and slowing metal clearance.

Ensuring adequate choline, particularly from foods like pasture-raised eggs or from highly bioavailable forms such as citicoline, helps maintain normal bile flow and preserves your liver's ability to remove metals efficiently.⁹

2. Bind metals in the gastrointestinal tract — After the liver transfers heavy metals into bile, they enter the intestines, where they need to be bound to prevent reabsorption back into circulation. Binders such as charcoal and calcium bentonite clay capture metals and other toxins in the gut, allowing them to be excreted. This step reduces the overall time heavy metals remain in your body.

3. Optimize glutathione availability — Glutathione acts as your body's primary intracellular detox molecule, binding heavy metals and neutralizing the oxidative stress they generate. Chronic toxic exposure increases glutathione demand, which can outpace production.¹⁰

Supporting your body's glutathione synthesis with precursors like N-acetylcysteine (NAC) or using liposomal or sublingual glutathione improves circulating levels and enhances your cells' capacity to safely neutralize and eliminate metals.

4. Activate Nrf2-driven detox pathways — Nrf2 is a transcription factor that switches on genes involved in antioxidant defense and toxin removal.¹¹ Compounds such as R-lipoic acid, sulfur-containing compounds from cruciferous vegetables and alliums, and certain polyphenols increase Nrf2 activity, strengthening your cells' ability to manage oxidative stress while supporting long-term detox resilience.

5. Incorporate high-intensity training into your routine — Performing high-intensity exercise for up to 75 minutes per week helps the body clear heavy metals more effectively. I don't recommend any more than that, though, as research shows you start losing longevity benefits when you go beyond 75 minutes a week.¹²

6. Support detox with sauna — Like exercise, sauna use supports heavy metal detox by increasing sweat production. If you are new to saunas, limit sessions to 20 to 30 minutes to avoid overheating and dehydration. Drink water before you go in and rehydrate immediately afterward. Adding electrolytes to your drink helps replace minerals lost through sweat and supports fluid balance during recovery.

For a synergistic effect, alternate sweat-inducing exercise and sauna sessions during the week, or add a short sauna session right after a workout. Pay close attention to how your body reacts to increased sweating from exercise and sauna use. Watch for signs of dehydration, such as dizziness, weakness, or unusual fatigue, and scale back when needed.

1. Choose appliances with brushless motor designs — When replacing or upgrading household appliances, selecting models that use brushless motors significantly reduces UFP emissions during normal operation. Brushless designs eliminate the mechanical friction and electrical sparking present in brushed motors, which directly lowers the amount of metal-containing particles released into the surrounding air.¹³

2. Use lower heat settings whenever possible — Since higher operating temperatures increase particle release from heating, using the lowest effective heat setting reduces the number of particles emitted while still allowing the appliance to perform its intended function, particularly for cooking and personal care devices.¹⁴

3. Use particle-emitting appliances wisely — Scheduling routine tasks using these appliances for times when living spaces are unoccupied by children and limit how long they run to reduce total particle release throughout the day.

Turning devices off as soon as tasks are finished avoids unnecessary emissions that add to indoor air pollution. Running multiple heat- or motor-driven appliances at the same time can also overwhelm ventilation and filtration systems, so staggering appliance use helps keep indoor concentrations within safer, more manageable ranges.

4. Ventilate rooms during and after appliance use — Opening windows or running exhaust fans creates airflow that carries UFPs out of enclosed spaces. That said, ventilation does not mean opening windows when outdoor air quality is poor, since this can bring pollutants indoors. Instead, open windows for at least 15 minutes a day when outdoor conditions are favorable, even in colder weather, to refresh your indoor air.

5. Use high-quality air filtration systems — Your home should be a protective space, not another source of pollutants. I suggest investing in air purifiers equipped with high-efficiency particulate air (HEPA) filters to remove UFPs and harmful pollutants from the air.

Keep windows and doors closed during peak pollution periods, such as rush hour or wildfire events, and run purifiers continuously. Replace filters on schedule so the system keeps working as intended and indoor air stays consistently clean. For more tips to improve your indoor air, read "Air Pollution Raises Dementia and Aneurysm Rupture Risk."