Aerosols in Foot Care: Understanding the Risk to Better Protect Against It

An aerosol refers to a collection of very fine solid or liquid particles suspended in air. Generally, three categories are distinguished: droplets, over 100 microns in diameter, which fall to the ground within seconds; fine aerosols, under that threshold, which can remain suspended for several minutes to several hours depending on ventilation; and ultrafine particles, under 5 microns, which can penetrate deep into the respiratory tract. In clinic, a bur rotating between 20,000 and 40,000 RPM inevitably generates a cloud of particles from the nail and skin being treated.

Nail drilling produces a mixture of keratin dust, nail fragments, dead skin, fungal spores, bacteria, cream or disinfectant particles, and sometimes microscopic blood or biological fluid, even in the absence of visible bleeding.

Nail fungal infections are likely the most frequent biological source encountered in practice. Onychomycosis typically contains dermatophytes, sometimes yeasts or molds, and drilling an infected nail releases spores, hyphal fragments, and contaminated dust that can remain suspended before being inhaled. This isn't hypothetical: a study conducted across seventeen podiatry clinics in Madrid detected Trichophyton rubrum and Trichophyton interdigitale in ambient air during nail drilling procedures, with a statistically significant association between clinical suspicion of onychomycosis and the presence of these dermatophytes in the air. An Australian study of nail dust collected in clinic found dermatophytes in 86% of samples analyzed, and some research has shown that this fungal dust can trigger an inflammatory response in the respiratory tract. A professional practicing over several decades therefore accumulates repeated exposure across thousands of hours of work.

Staphylococcus aureus, skin staphylococci, streptococci, Pseudomonas, and Corynebacterium are frequently found, in variable quantities depending on the condition of the foot being treated, and the presence of ulcers, fissures, or active infection. Viral risk is considerably lower, though not absent, in the presence of plantar warts of viral origin. The literature establishes this risk mainly in the context of vapor generated by laser or electrocautery procedures, where viral DNA has been found in the resulting plume, and on nail files used for wart debridement, where papillomavirus DNA can persist. Data specific to rotary drilling remain more limited, but caution is warranted.

Suspended particles can be inhaled or progressively settle on surfaces throughout the treatment room: furniture, the lamp, handles, screens, the chair, instruments, clothing, hair, and masks. How long particles stay suspended depends on their size, ventilation, air turnover, and humidity. Without adequate ventilation, larger particles settle quickly, while the finest can remain suspended for several tens of minutes, sometimes longer — gradually contaminating the work environment.

Effective dust extraction captures particles directly at the source, before they disperse into the room. The closer the nozzle is to the drilling site and the better maintained the system, the greater the reduction in ambient dust. Key criteria include high airflow, strong suction, a nozzle positioned close to the bur, high-efficiency filters — often HEPA or equivalent depending on the manufacturer — and regular filter replacement. That said, one study reported that brief exposure to airborne dermatophytes can still occur at certain points during the workday despite the use of a dust extraction system, a reminder that extraction reduces risk without eliminating it entirely.

Some nail drills incorporate a water spray system, which offers a cooling effect, greater patient comfort, and reduced dry dust. However, this spray can also create a mist of microdroplets and increase liquid dispersion if the accompanying extraction is insufficient. Systems combining spray with effective extraction are generally preferable to spray used on its own.

Chronic exposure to aerosols can contribute to eye irritation, rhinitis, allergies, persistent cough, occupational asthma, reduced respiratory function in sensitive individuals, and skin irritation. Professionals practicing for decades without adequate extraction represent the most exposed group.

Best practices include using a nail drill equipped with effective dust extraction, wearing an appropriate respiratory mask (an N95 or FFP2 mask filters fine particles more effectively than a standard surgical mask), wearing glasses or a face shield, ensuring good air turnover, replacing filters according to manufacturer recommendations, cleaning surfaces between patients, avoiding compressed air to disperse dust, and regularly maintaining the extraction system.

Several findings recur consistently across studies on this topic: drilling nails and skin produces aerosols containing measurable biological particles, source extraction considerably reduces their dispersion, good ventilation complements this protection without replacing it, and personal protective equipment becomes particularly important when treating fungal nails or wart-related lesions. An effective strategy therefore relies on several complementary measures — high-performance integrated dust extraction, well-maintained high-efficiency filtration, adequate room ventilation, an appropriate respiratory mask, and systematic disinfection of surfaces and equipment — which together reduce staff exposure, cross-contamination risk, and particle buildup in the clinical environment.