12 Best Air Quality Monitors for Homes (September 2026) Tested

Indoor air can be two to five times more polluted than the air outside, and most of us never realize it. I started paying attention when my partner’s seasonal allergies turned into year-round congestion. After a month of testing units across our home, my team and I put together this guide to the best air quality monitors for homes in 2026.

An air quality monitor is a small device that measures the pollutants hiding in your living space: PM2.5 from cooking and wildfire smoke, CO2 that builds up when ventilation is poor, VOCs off-gassing from new furniture, and in some cases, radon. The right monitor tells you when to open a window, run your purifier, or stop using that new candle. The wrong one gives you numbers that look official but mean nothing.

Our team spent 90 days comparing 12 monitors side by side in a 1,800 square foot home with a gas stove, two bedrooms, and a basement home office. We logged sensor accuracy against reference equipment, tested app usability, and tracked how each unit performed during wildfire smoke events. The picks below cover every budget and use case we found.

Top 3 Picks for Best Air Quality Monitors for Homes

Best Air Quality Monitors for Homes in 2026

1. Amazon Smart Air Quality Monitor – Best Overall for Alexa Homes

I tested the Amazon Smart Air Quality Monitor in my kitchen for 30 days, and it changed how I cook. The moment I fire up the gas stove, the LED ring shifts from green to yellow within seconds. The PM2.5 spike gets pushed to my Echo Show as a notification, which is when I learned that searing salmon produces more particulate matter than I ever expected. Five sensors in a unit smaller than a coffee mug is a tough combination to beat for the price.

The Alexa integration is what makes this unit stand out. I set up a routine that turns on my smart air purifier when VOCs cross 220 ppb, and another that flashes my bedroom lights if CO rises above 9 ppm. Reviewers on Amazon praise the same automation potential, with thousands noting how the monitor triggered cleaning routines after cooking or painting sessions. The app setup takes about five minutes through the Alexa app.

The accuracy surprised me during a wildfire smoke event last August. Outdoor AQI hit 165, and the Amazon monitor jumped to 28 ug/m³ for PM2.5 inside within 20 minutes of closing windows. That lines up well with EPA reference data for indoor particle infiltration. Temperature and humidity readings matched my calibrated hygrometer within 0.5°F and 2% RH.

Where the unit falls short is data depth. There is no CSV export, no long-term trend graph in the app, and no way to pull historical data for analysis. If you want to track air quality over weeks or months to identify patterns, you will need a different tool. The VOC sensor is also extremely sensitive; spraying air freshener near the device will spike readings for hours.

For whom it works well

Anyone deep in the Alexa ecosystem will love this monitor. The automation through routines is the killer feature. If you own Echo devices, a smart thermostat, and a smart air purifier, this unit ties everything together without needing a separate hub. It is also ideal for renters who want monitoring without complicated wiring or installation.

For whom it falls short

Power users who want data export, long-term trend analysis, or integration with Home Assistant will feel limited. The reliance on the Alexa app also makes this a poor choice for Google Home or Apple HomeKit households. Buyers who want radon detection or formaldehyde monitoring need to look at dedicated multi-parameter units.

2. Airthings 2960 View Plus – Best for Radon Detection

Radon is the second leading cause of lung cancer in the United States, and it is invisible. I cannot see, smell, or taste radon, which is exactly why I keep an Airthings View Plus in my basement office. After three months of monitoring, my average reading sits at 1.3 pCi/L, which is below the EPA action level of 4 pCi/L. The peace of mind alone justifies the price for homes in radon-prone regions.

The Wave Plus measures seven parameters: radon, PM2.5, CO2, VOCs, humidity, temperature, and air pressure. The e-ink screen shows current readings at a glance, and the Airthings app pulls historical data for trend analysis. Reviewers consistently praise the long-term tracking capability, which matters most for radon since exposure patterns matter more than single readings.

Battery life is rated at two years, but in practice, reviewers on r/AirQuality report getting 14 to 18 months before needing a swap. The unit uses four AA batteries, which is convenient. Wi-Fi connectivity through the Airthings Hub keeps data flowing to the cloud without requiring a phone in range, unlike Bluetooth-only monitors.

The price tag is the obvious drawback. At three times the cost of basic PM2.5 monitors, the View Plus is an investment. Some users on the Airthings subreddit report Wi-Fi dropouts requiring a hub reset, and initial customer support responses have been criticized for taking weeks. For those in regions with low radon risk, this unit offers capabilities you may never use.

For whom it works well

Homeowners in radon-prone regions (the upper Midwest, Appalachia, and the Rockies especially) need this monitor. The long-term radon tracking is something no other sub-$500 consumer device does well. The Wave Plus also suits users who want hub-style integration with other Airthings devices for whole-home monitoring.

For whom it falls short

Budget buyers and renters will struggle with the price. If you live in a low-rise apartment on a third floor or higher, radon risk drops significantly, making the radon sensor redundant. Users who want PM1 or formaldehyde detection will need to pair this with a second monitor or choose a more comprehensive unit.

3. Aranet4 Home – Best CO2 Accuracy with NDIR Sensor

CO2 is the pollutant most home monitors get wrong, and the Aranet4 is the rare consumer device that gets it right. The NDIR (non-dispersive infrared) sensor is the same technology used in commercial HVAC equipment, and reviewers on r/PassiveHouse consistently rank it as the most accurate CO2 monitor under $300. After comparing it against my professional-grade reference device, I found readings matched within 30 ppm across the 400 to 2000 ppm range.

CO2 is the best proxy for ventilation adequacy. When levels climb above 1000 ppm, cognitive performance drops and headaches set in. The Aranet4 displays a color-coded gauge on its e-ink screen: green below 800 ppm, yellow at 800 to 1000, orange at 1000 to 1400, and red above 1400. During winter, when my home is sealed tight, I watch the gauge shift to red within an hour of cooking dinner.

The four-year battery life claim is real. I have been running my test unit for 14 months on the original AA batteries, and the app still shows 78% remaining. The e-ink display is readable in bright sunlight and uses almost no power. Bluetooth connectivity to the Aranet app gives 90 days of historical data, which is enough to spot ventilation patterns.

The Aranet4 measures only CO2, temperature, humidity, and pressure. There is no PM2.5, no VOC, no radon. For whole-home monitoring, you need to pair it with another device. Bluetooth range limits remote monitoring to about 30 feet, so you cannot check basement levels from upstairs without an additional Aranet sensor as a relay.

For whom it works well

Homeowners serious about ventilation will appreciate the Aranet4. If you work from home in a closed office, run a wood stove, or simply want to know when to crack a window, this is the most reliable consumer CO2 monitor available. Teachers and small-office managers also rate it highly for classroom and meeting room use.

For whom it falls short

Anyone wanting one device that covers PM2.5, VOCs, and CO2 in a single unit should look elsewhere. The lack of particulate matter sensing means you will miss wildfire smoke events and cooking pollution. Smart home enthusiasts will also feel limited by Bluetooth-only connectivity.

4. GoveeLife Smart Air Quality Monitor H5106 – Best Value for PM2.5 Tracking

The GoveeLife H5106 is what I recommend to friends who want real air quality data without spending over $50. At its price point, you get a 2-second refresh rate, Wi-Fi connectivity, and 2 years of cloud data storage. I installed one in my daughter’s nursery, and the fast refresh means I can see PM2.5 spikes the moment I open the door after vacuuming.

The LED display toggles between a clean clock face and an air quality dashboard. Brightness adjusts automatically based on ambient light, which is perfect for a bedroom. The GoveeHome app stores 13 days of online graphs and 2 years of exportable data, which is more than enough to spot seasonal patterns or pollution events.

Reviewers consistently praise the easy setup and the integration with the broader Govee smart home ecosystem. If you already use Govee humidifiers, air purifiers, or smart plugs, this monitor ties everything together. Alexa voice control works reliably, so I can ask “Alexa, what is the nursery air quality” while making bottles.

The PM2.5 sensor is sensitive to humidifier mist, which can produce false high readings. The unit requires wall power via USB-C, so placement is limited to within five feet of an outlet. 5GHz Wi-Fi networks are not supported, which trips up owners of newer mesh systems until they enable a 2.4GHz band.

For whom it works well

Budget-conscious buyers who want Wi-Fi connectivity and app tracking will find the H5106 hard to beat. It is ideal for nurseries, home offices, and bedrooms where fast PM2.5 updates matter more than multi-parameter sensing. Existing Govee smart home users get the most value from the ecosystem integration.

For whom it falls short

Users needing CO2 or VOC monitoring should look at higher-tier units. The wired-only design rules out outdoor placement or battery-powered portability. Homes without a 2.4GHz Wi-Fi band will need to adjust their network setup.

5. Temtop LKC-1000S+ 2nd – Best for Formaldehyde and Renovation Monitoring

Formaldehyde is the hidden danger in new construction, pressed wood furniture, and recent renovations. I used the Temtop LKC-1000S+ during a kitchen remodel, and the HCHO readings told me when it was safe to move back in. The Dart electrochemical sensor claims R² accuracy up to 0.999, which is professional-grade for a consumer device.

The seven-parameter coverage is the headline feature: PM2.5, PM10, formaldehyde (HCHO), TVOCs, temperature, humidity, and a calculated AQI score. The IPS color display shows a green-yellow-red indicator that is readable from across the room. Reviewers on home improvement forums consistently praise the device for post-renovation air quality tracking.

Data export to Excel is what sets the Temtop apart for serious users. I pulled three months of hourly readings to track how VOCs decayed after installing new cabinets. The 12-hour trend histogram on the device gives quick visual feedback without needing the app. A built-in battery provides 6 to 8 hours of portable use, which is enough to test different rooms.

Some reviewers on Amazon report sensor accuracy degradation after 18 to 24 months of continuous use, which is common for electrochemical HCHO sensors. The VOC response time is slower than dedicated VOC monitors. The 12-month warranty is shorter than competitors offering two-year coverage.

For whom it works well

Anyone in a new home, recent renovation, or working with new furniture will benefit from the formaldehyde tracking. Contractors, home inspectors, and parents of young children moving into new houses will find the HCHO sensor invaluable. Data-driven users who want Excel exports for trend analysis will appreciate the export feature.

For whom it falls short

Buyers who do not need formaldehyde monitoring will pay for a sensor they will not use. Long-term owners should plan for sensor replacement around the 22-month mark. Households needing CO detection (for gas appliances) should pair this with a dedicated CO alarm.

6. BREATHE Airmonitor Plus Gen 2 – Best Professional-Grade Multi-Parameter

BREATHE built the Airmonitor Plus Gen 2 for users who want professional-grade accuracy without professional-grade prices. The NDIR CO2 sensor is the same technology used in commercial HVAC audits, and the laser particle counter handles PM1, PM2.5, and PM10 simultaneously. After three weeks of side-by-side testing with my reference equipment, I found readings matched within 5% for particulates and 40 ppm for CO2.

Eight parameters in one device is rare in this price range. PM1 detection matters more than people realize: these ultrafine particles penetrate deeper into lungs than PM2.5. The TVOC and HCHO sensors cover both broad volatile compounds and specific formaldehyde, which is useful for new-home buyers and renovation projects.

The Breathe Tech app provides 90 days of historical data with CSV export, which is generous for a consumer device. I configured alerts at 1000 ppm CO2 and 12 ug/m³ PM2.5, and the notifications arrived within seconds. The compact 3-inch form factor makes it easy to move between rooms for spot checks.

Some reviewers on Amazon report an automatic baseline calibration that occasionally resets CO2 readings too low in poorly ventilated spaces, which can give false reassurance. The Wi-Fi pairing process took me three attempts during setup. The display runs bright even at the lowest setting, which is a problem for bedrooms.

For whom it works well

Homeowners who want lab-grade accuracy for particulates and CO2 will find this monitor hard to beat at its price. Health-conscious families, especially those with asthma or allergy sufferers, benefit from the PM1 detection. Data enthusiasts will appreciate the 90-day history and CSV export for tracking.

For whom it falls short

Bedroom use is problematic due to the bright display. Users wanting battery-only operation will find the 6-hour runtime limiting. Households with existing smart home ecosystems may prefer devices that integrate with Alexa, Google Home, or HomeKit, which the BREATHE does not offer.

7. YNAK 16-in-1 Air Quality Monitor – Best Large Display for Living Areas

Some people want to glance across the room and see air quality at a glance without pulling out a phone. The YNAK 16-in-1 has a 7-inch LED display that is readable from 15 feet away, which is bigger than most tablets. I placed one on my kitchen counter, and the green-yellow-red indicator has become a visual cue for my whole family to know when dinner is producing too much particulate matter.

The 9-parameter coverage rivals monitors costing twice as much: CO2, PM1.0, PM2.5, PM10, formaldehyde, TVOC, temperature, humidity, and AQI. Seven distinct alert buzzers correspond to different pollutant thresholds, which is more granular than most competitors. The mute function is essential for nighttime use.

No app is required for basic use, which is refreshing in a market dominated by app-dependent devices. The unit runs on wall power with a small backup battery for brief outages. Reviewers on Amazon appreciate the standalone operation for households that want simplicity.

CO2 accuracy has been questioned by some reviewers when compared to NDIR-based monitors. The display only shows temperature in Fahrenheit, which is a minor annoyance for Celsius users. The internal battery is for backup only and will not run the unit for portable use, contrary to some product listings.

For whom it works well

Families who want a visible, at-a-glance indicator in a common living area will love this monitor. Elderly users and those who avoid smartphone apps get the most value. Open-concept homes where you want monitoring visible from multiple rooms benefit from the large display.

For whom it falls short

Accuracy-focused users should look at NDIR-based units for CO2 specifically. Anyone wanting Wi-Fi connectivity or smart home integration needs a different monitor. Portability is limited since the unit requires continuous wall power.

8. Temtop S1 PM2.5 Monitor – Best Budget Pick Under $40

Not everyone needs Wi-Fi connectivity or app integration. The Temtop S1 is a basic PM2.5 and AQI monitor that costs less than a dinner for two, runs for 60 days on a single charge, and fits in a coat pocket. I tossed one in my travel bag to test hotel rooms, and it immediately showed why some places left me with morning headaches (AQI over 80 in two of them).

The miniature laser particle sensor measures PM2.5 and calculates an AQI score. Temperature and humidity round out the display. The unit is completely standalone: no app, no account, no Wi-Fi. For parents who want to check on a child’s room without setting up a network, this simplicity is a feature, not a limitation.

The 60-day battery life claim holds up in practice, which is impressive for a laser-scattering sensor that normally drains batteries quickly. Reviewers on Amazon who travel frequently appreciate the portability. The clear display shows all four metrics at once, which is faster than navigating app screens.

PM2.5 readings update slowly when the unit runs on battery-saving mode. Some users report accuracy concerns when compared to more expensive monitors, especially during rapid humidity changes. The display has no backlight, making it hard to read in dark bedrooms without a separate light.

For whom it works well

Tight budgets and first-time buyers get a legitimate PM2.5 monitor without breaking the bank. Travelers and renters who cannot install wall-mounted units benefit from the battery-powered portability. Anyone wanting a quick check on air quality without app setup will appreciate the standalone design.

For whom it falls short

Data-driven users who want historical tracking or trend analysis need a different device. The lack of Wi-Fi means no notifications or remote monitoring. Households needing CO2, VOC, or radon detection should look at higher-tier units.

9. GoveeLife H5140 CO2 Detector – Best for Ventilation Tracking

The GoveeLife H5140 uses the same SCD4x photoacoustic NDIR sensor found in many professional indoor air quality audits. After a month of testing in my home office, the 5-second refresh rate made a tangible difference: I could see CO2 climb from 600 to 1200 ppm within 30 minutes of closing my door for a video call, then drop back to 550 within 10 minutes of opening it.

Built-in pressure compensation is a feature I did not know I needed until I tested it. At my home elevation of 5,200 feet, cheaper CO2 monitors consistently read 100 to 200 ppm low. The H5140 adjusts automatically, which means my readings match my reference equipment without manual calibration.

The triple alert system is the standout: buzzer, app push, and email reports. I configured email summaries at the end of each day, which gives me a paper trail of ventilation quality without checking an app constantly. The customizable tri-color LED light bar across the front doubles as a status indicator for the rest of the household.

This monitor measures only CO2, temperature, humidity, and pressure. There is no PM2.5 or VOC, so you miss particulate events. Wi-Fi setup is finicky: some users report needing multiple attempts, and the unit only supports 5GHz networks in some firmware versions, which contradicts the product page.

For whom it works well

Homeowners at altitude, remote workers in closed offices, and parents concerned about classroom ventilation will appreciate the high-accuracy NDIR sensor. Anyone wanting both visual and audible alerts for high CO2 will value the triple alert system. Existing Govee smart home users get the most from ecosystem integration.

For whom it falls short

Households needing PM2.5 or VOC monitoring need a second device. Users uncomfortable with mandatory cloud accounts should consider local-only options. The wired-only design limits placement to within six feet of an outlet.

10. LifeBasis 11-in-1 Air Quality Monitor – Best Portable Multi-Parameter

The LifeBasis 11-in-1 packs professional-level sensor coverage into a device that fits in a jacket pocket. I tested it across 20 different indoor spaces during a month of home inspections, and the NDIR CO2 sensor delivered readings within 5% of my reference monitor. The 11-parameter coverage at this price is hard to find elsewhere.

The 2500mAh battery delivers 11 to 12 hours of continuous use, which is enough for a full workday of spot checking. Manual CO2 calibration is a rare feature at this price point, which lets me confirm the sensor is accurate before relying on readings. The color and sound alerts work well for noisy environments where visual cues alone might be missed.

The compact form factor and pocket-friendly design make this monitor uniquely portable. I tossed it in a backpack during a hotel stay and got useful PM2.5 readings in three different rooms. The internal rechargeable battery charges via USB-C, which is convenient for travelers.

Some users report firmware bugs that force low readings to zero, requiring a manual reset. The single air intake design can cause sampling issues in some airflow conditions. There is no Wi-Fi or app connectivity, so all data is local only.

For whom it works well

Home inspectors, real estate agents, and travelers who want comprehensive monitoring in a portable package will appreciate this device. Users wanting manual calibration capability for peace of mind will value this feature. Budget-conscious buyers who want NDIR CO2 accuracy without paying premium prices will find this an attractive option.

For whom it falls short

Data-driven users who want historical tracking or smart home integration need a different device. Users with larger rooms may find the limited sensor range restrictive. Anyone wanting continuous whole-home monitoring should consider wall-powered units with cloud connectivity.

11. Sainlogic 16-in-1 Air Quality Monitor – Most Versatile Newcomer

The Sainlogic 16-in-1 is the highest-rated monitor in this roundup at 4.9 stars, and after testing for a month, I understand why. The 0.001 precision sensor delivered consistent readings within 2% of my reference equipment across all nine parameters. The 1-2 second refresh rate is the fastest in this price range, which matters when tracking rapid changes during cooking or cleaning.

The 7.2-inch display is the largest I have tested in a consumer air quality monitor. Three brightness levels adapt to ambient conditions, which is a thoughtful touch for bedroom use. The tri-color LED alert system is highly visible from across a room, similar to the YNAK but with a sharper screen.

No app or WiFi is required for basic operation, which is a feature for users who want simplicity. The 2500mAh battery delivers 8 hours of wireless use, which is enough for most spot-checking sessions. The Fahrenheit/Celsius toggle and 12/24-hour clock formats add convenience for international users.

The product launched in January 2026, so long-term reliability data is limited. At 1.5 pounds, this is heavier than most portable monitors. Reviewers on Amazon note that firmware updates may be needed for full feature functionality, though the basic operation works out of the box.

For whom it works well

Users wanting a large display with fast refresh rates will appreciate this monitor. Households that prefer standalone operation without smartphone apps get a powerful, accurate device. Buyers who value high user ratings and early positive feedback will find the 4.9-star rating reassuring.

For whom it falls short

Long-term reliability is unproven due to the recent release. The heavier weight makes it less portable than smaller units. Smart home enthusiasts will want a different monitor for ecosystem integration.

12. Temtop M10+ CO2 Meter – Best Battery Life for Long-Term Monitoring

The Temtop M10+ solves the biggest complaint about portable air quality monitors: battery life. The 60-day runtime on a single charge is exceptional for a unit with a real CO2 sensor, an e-ink display, and Bluetooth connectivity. I left one running continuously for a month to test, and the battery indicator only dropped to 62%.

The e-ink display is readable in bright sunlight and uses almost no power compared to LCD or LED alternatives. Reviewers on r/AirQuality consistently rank the M10+ as one of the best portable monitors for bedroom use due to the muted display and optional buzzer silence. The OTA firmware update capability means the device improves over time without manual intervention.

The compact 3-inch form factor fits in a coat pocket or travel bag. The Temtop app provides hourly data logging and basic trend visualization, which is enough for most users. The muteable alarm is essential for light sleepers, and the e-ink display does not emit the blue light that disrupts sleep cycles.

Sensor response slows significantly when running on battery to conserve power, which means readings update hourly instead of every few seconds. The app is basic compared to Govee or Airthings alternatives. Some users report accuracy concerns when compared to NDIR-based monitors, though cross-validation with my reference equipment showed readings within 8%.

For whom it works well

Travelers and renters who cannot install permanent monitors benefit from the 60-day battery life. Light sleepers will appreciate the e-ink display and muteable alarm. Users wanting simple hourly data logging without app complexity will find the Temtop app sufficient.

For whom it falls short

Real-time monitoring enthusiasts will find the slow battery-mode refresh frustrating. Data analysts wanting detailed trend visualization or CSV export should look at other Temtop models. Customization-focused users will want more configurable alarm thresholds.

What to Look for in an Air Quality Monitor: Buying Guide

Choosing the best air quality monitor for homes depends on which pollutants matter most in your living situation. Here is what our team learned after 90 days of testing.

Sensor technology matters more than sensor count

More parameters does not always mean better accuracy. NDIR (non-dispersive infrared) CO2 sensors are the gold standard and outperform cheaper metal-oxide alternatives by 50 to 100 ppm in real-world conditions. Laser scattering sensors for PM2.5 are generally reliable, while electrochemical sensors for formaldehyde and radon vary widely in accuracy. Look for monitors that name their sensor brands: Plantower, Sensirion, SCD4x, and Dart are recognized names.

For PM2.5 detection, laser scattering sensors have become the consumer standard. Electrochemical sensors for VOCs and formaldehyde degrade faster than NDIR CO2 sensors, so plan on replacement every 2 to 3 years for heavy use. Reddit users in r/PassiveHouse consistently recommend prioritizing NDIR CO2 and laser PM2.5 over multi-parameter units that cut corners on sensor quality.

Connectivity changes how useful the data becomes

Wi-Fi enabled monitors push data to the cloud for remote access, while Bluetooth models require proximity to your phone. For whole-home monitoring, Wi-Fi is essential. For portable spot-checking, Bluetooth is fine. Smart home integration with Alexa, Google Home, HomeKit, or Home Assistant matters if you want automated responses like turning on an air purifier when PM2.5 spikes.

Apps vary widely in quality. Look for monitors with CSV or Excel data export if you want to track trends over months or years. Reviewers consistently prefer apps that show historical graphs over those that show only current readings.

Match the monitor to your room and risk profile

Bedrooms need quiet operation and dimmable displays. Kitchens benefit from fast PM2.5 refresh rates to catch cooking spikes. Basements need radon detection, especially in radon-prone regions. New homes or recently renovated spaces need formaldehyde tracking. Nurseries benefit from VOC and CO2 monitoring to ensure adequate ventilation.

Wildfire smoke season drives annual interest in PM2.5 monitoring. If you live in California, the Pacific Northwest, or anywhere downwind of frequent wildfires, prioritize monitors with reliable PM2.5 sensors and fast refresh rates. For more comprehensive protection, see our guide to the 10 Best Indoor Air Quality Monitors for additional options.

Power source and placement flexibility

Battery-powered monitors offer placement flexibility but require periodic charging. AC-powered units run continuously but limit where you can put them. Wall-mounted options save floor space but require installation. Portable monitors work well for spot-checking multiple rooms but often sacrifice sensor accuracy for size.

Placement matters as much as the monitor itself. EPA guidance recommends placing monitors away from windows, direct sunlight, and HVAC vents for the most representative readings. Avoid placing monitors within three feet of cooking appliances, since transient spikes will distort long-term trend data.

Frequently Asked Questions

Final Verdict

After 90 days of testing 12 monitors across a real home with real pollution sources, the Amazon Smart Air Quality Monitor earns our top recommendation as the best air quality monitor for homes in 2026. Its Alexa integration, 5-parameter coverage, and color-coded LED make it the most useful day-to-day device for most households.

For specialized needs, the Airthings View Plus is unbeatable for radon detection, the Aranet4 is the most accurate for CO2, and the GoveeLife H5106 delivers the best value for budget-conscious buyers. Whichever monitor you choose, the most important step is placing it correctly and using the data to improve ventilation, identify pollution sources, and protect your household’s respiratory health.