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Completed

NCT Number: NCT07477834

Assessing the Health Impact of Indoor Air Purification Using Health Data Obtained From Apple Watch Wearers

This study aims to use the Apple Watch health metrics to assess short-term physiological responses in a randomized, double-blind, crossover real-world indoor purification intervention.

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Key information

Conditions

Air Pollution Exposure HRV Heart Rate Respiratory Rate Resting Heart Rate Sleep SpO2

Age range

18 year–40 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

New York University Abu Dhabi

Abu Dhabi, United Arab Emirates

About this study

Fine particulate matter (PM2.5) poses significant health risks. While indoor air purification is a proven mitigation approach, most studies have used medical devices with limited usability and practicality. Thus, this study aims to use the Apple Watch health metrics to assess short-term physiological responses in a randomized, double-blind, crossover real-world indoor purification intervention with the IQAir Atem X, the first of its kind in the UAE.

The study aims to recruit 42 healthy, non-smoking young adults to undergo two 2-week interventions (real and sham filters), separated by a 1-week washout, at the New York University Abu Dhabi campus. Collected Apple Watch metrics include: heart rate, heart rate variability, daily resting heart rate, sleep respiratory rate, blood oxygen saturation, and sleep stages durations. Daily time-location surveys enable personal PM2.5 exposure estimation from fixed-site sensors. Physiological outcomes and their associations with filtration and PM2.5 exposure are analyzed with paired tests and linear mixed-effect regression models.

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Own an Apple Watch Series 6 or above
  • Own an iPhone
  • iPhone and Apple Watch updated to the latest software versions (iOS 18 and watchOS 11, as of January 2025) to ensure consistent and latest algorithms for measuring health
  • Age range: 18 - 40
  • Non-smoker, defined as never smoke in life or have stopped smoking for at least one year before the start of the study

Exclusion criteria

  • Own a Apple Watch sold by Apple in the United States on or after January 18, 2024 which does not support SpO2 measurements. These are indicated with part numbers ending in LW/A.
  • Own or currently use an air quality monitor that can measure particulate matter
  • Own or currently use an air purifier (humidifier or scent diffuser is fine)
  • Any known pre-existing conditions: asthma, diabetes, obesity (BMI > 30), or chronic cardiorespiratory disease
  • Taking any medications that might affect the heart and lung function

Treatment and study plan

Real Filtration

Behavioral

IQAir Atem X purifier with real filter (HyperHEPA) which is designed to remove PM2.5

Sham Filtration

Behavioral

IQAir Atem X purifier with sham filter which does not filter any PM2.5. When installed inside the purifiers, the sham filter produced the same appearance and sound as the real one, making the two interventions indistinguishable to participants.

Primary outcomes

  1. Heart Rate Changes

    Time frame: During each 2-week intervention (real and sham filtration); 1-week washout period is excluded

    Instantaneous heart rate is measured by the Apple Watch in the background throughout the two interventions. Values are compared between the real and sham filtration to assess the effect of air purification.

    Unit: number of heartbeats per minute

  2. Daily Resting Heart Rate Changes

    Time frame: During each 2-week intervention (real and sham filtration); 1-week washout period is excluded

    Resting heart rate is the daily average heart rate during rest measured by the Apple Watch in the background, reported by the Apple Watch as one single aggregated value per day, throughout the two interventions. Values are compared between the real and sham filtration to assess the effect of air purification.

    Unit: number of heartbeats per minute

  3. Heart Rate Variability Changes

    Time frame: During each 2-week intervention (real and sham filtration); 1-week washout period is excluded

    Heart rate variability, variation in time between consecutive heartbeats, is measured by the Apple Watch in the background throughout the two interventions. The Apple Watch specifically measures the Standard Deviation of NN intervals (SDNN). Values are compared between the real and sham filtration to assess the effect of air purification.

    Unit: millisecond

  4. Oxygen Saturation Changes

    Time frame: During each 2-week intervention (real and sham filtration); 1-week washout period is excluded

    Percentage of blood oxygen saturation is measured by the Apple Watch in the background throughout the two interventions. Values are compared between the real and sham filtration to assess the effect of air purification.

    Unit: %

  5. Sleep Respiratory Rate Changes

    Time frame: During each 2-week intervention (real and sham filtration); 1-week washout period is excluded

    Respiratory rate is measured by the Apple Watch in the background during sleep throughout the two interventions. Values are compared between the real and sham filtration to assess the effect of air purification.

    Unit: number of breaths per minute

  6. Sleep Stages Durations Changes

    Time frame: During each 2-week intervention (real and sham filtration); 1-week washout period is excluded

    Nightly duration of sleep stages (Core, Deep, REM, and Awake) is calculated by summing individual sleep samples and their respective timestamps as measured by the Apple Watch in the background during sleep throughout the interventions. Values are compared between the real and sham filtration to assess the effect of air purification.

    Unit: hour

Sponsors and collaborators

Lead sponsor

New York University Abu Dhabi

Other

Collaborators

  • IQAir AG
  • LUT University

Registry information

Important dates

Study start
2025
Primary completion
2025
Study completion
2025
First posted
Mar 17, 2026
Registry last updated
Mar 17, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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