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

March 12, 2026 updated by: Samreen Malik, New York University Abu Dhabi
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.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Detailed Description

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.

Study Type

Interventional

Enrollment (Actual)

42

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult

Accepts Healthy Volunteers

Yes

Description

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

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Prevention
  • Allocation: Randomized
  • Interventional Model: Crossover Assignment
  • Masking: Double

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Real filtration first, followed by sham filtration
Participants were randomly assigned to begin with either the real filter or sham filter, before switching halfway into the study. This group first received real air filtration for 2 weeks, followed by a 1-week washout period, and then 2 weeks of sham filtration.
Behavioral: Real Filtration
IQAir Atem X purifier with real filter (HyperHEPA) which is designed to remove PM2.5
Behavioral: Sham Filtration
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.
Placebo Comparator: Sham filtration first, followed by active filtration
Participants were randomly assigned to begin with either the real filter or sham filter, before switching halfway into the study. This group first received sham filtration for 2 weeks, followed by a 1-week washout period, and then 2 weeks of real filtration.
Behavioral: Real Filtration
IQAir Atem X purifier with real filter (HyperHEPA) which is designed to remove PM2.5
Behavioral: Sham Filtration
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.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
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
During each 2-week intervention (real and sham filtration); 1-week washout period is excluded
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
During each 2-week intervention (real and sham filtration); 1-week washout period is excluded
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
During each 2-week intervention (real and sham filtration); 1-week washout period is excluded
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: %
During each 2-week intervention (real and sham filtration); 1-week washout period is excluded
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
During each 2-week intervention (real and sham filtration); 1-week washout period is excluded
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
During each 2-week intervention (real and sham filtration); 1-week washout period is excluded

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

New York University Abu Dhabi

Collaborators

IQAir AG
LUT University

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

February 9, 2025

Primary Completion (Actual)

June 22, 2025

Study Completion (Actual)

June 22, 2025

Study Registration Dates

First Submitted

March 12, 2026

First Submitted That Met QC Criteria

March 12, 2026

First Posted (Actual)

March 17, 2026

Study Record Updates

Last Update Posted (Actual)

March 17, 2026

Last Update Submitted That Met QC Criteria

March 12, 2026

Last Verified

February 1, 2026

More Information

Terms related to this study

Keywords

Other Study ID Numbers

  • HRPP-2024-148

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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