Indoor Air Quality and Allergies

The air inside your home can be 2–5× more polluted than outdoor air. For allergy sufferers, indoor air quality isn't a luxury — it's a treatment. Here's what actually matters and what doesn't.

AQI EXPLAINEDHEPA SCIENCEHIGH-IMPACT CHANGES
2–5×
Indoor air can be more polluted than outdoor air (EPA)
90%
Of time Americans spend indoors on average
0.3μm
Minimum particle size HEPA captures — smaller than all pollen
MERV 13
Minimum HVAC filter rating to capture pollen effectively

Understanding the Air Quality Index (AQI)

The AQI measures outdoor air quality on a 0–500 scale, covering five major pollutants: ground-level ozone, particle pollution (PM2.5 and PM10), carbon monoxide, sulfur dioxide, and nitrogen dioxide. For allergy sufferers, the most relevant metrics are PM2.5 (fine particles that penetrate deep into airways) and ozone (which inflames airways and amplifies allergic reactions).

AQI RangeCategoryAllergy Impact
0–50GoodNo additional concern
51–100ModerateSensitive groups may notice airway irritation
101–150Unhealthy for Sensitive GroupsAllergy sufferers should limit prolonged outdoor activity
151–200UnhealthyAvoid extended outdoor exposure; HEPA filtration critical indoors
201+Very Unhealthy / HazardousStay indoors; N95 masking if outdoor activity essential

The critical insight for allergy sufferers: high AQI and high pollen compound each other. Ozone inflames airway tissue, making it more reactive to pollen. A day with moderate pollen and high ozone can feel worse than a day with high pollen and good AQI. Anthos shows you both metrics together for this reason.

HEPA Filtration — The Science

HEPA (High-Efficiency Particulate Air) is a standard, not a brand. A true HEPA filter must capture 99.97% of particles 0.3 microns or larger. Every pollen grain — the smallest of which (grass) is approximately 10 microns — is captured at 100% efficiency. Every mold spore. Most dust mite allergen particles. HEPA is genuinely transformative for indoor air quality for allergy sufferers.

Room Size Matters

Every HEPA purifier is rated for a specific room size (measured in CADR — Clean Air Delivery Rate). A purifier rated for 200 sq ft won't adequately clean a 400 sq ft bedroom. Match the purifier's CADR rating to your room size.

Continuous Operation

Running a HEPA purifier only when you're symptomatic is the wrong approach. Continuous operation during pollen season maintains a consistent low-allergen baseline. Pollen accumulates on surfaces and recirculates — continuous filtration prevents buildup.

Placement Matters

Place the purifier near your breathing zone — at mattress height in the bedroom, not across the room on a shelf. For living spaces, central placement with unobstructed airflow maximizes effectiveness.

Filter Replacement

HEPA filters become less effective as they load with particles. During heavy pollen season, check filters monthly. A loaded filter doesn't just stop working — it can become a reservoir that releases particles back into the air.

What AQI Monitors Tell You

Consumer indoor air quality monitors measure PM2.5, temperature, humidity, CO2, and sometimes VOCs (volatile organic compounds). They're useful for identifying: humidity levels (keep 40–50%), unusual particulate events (a candle, cooking, or opening windows on high-pollen days), and whether your HEPA purifier is actually reducing indoor particle counts.

Anthos integrates real-time outdoor AQI data alongside pollen counts in your daily reading — giving you the full picture of what the air is doing on any given day, indoors and out.

See the full air picture every morning.

Anthos shows you pollen levels AND air quality index together — the combination that actually determines how your airways feel.

Download on the App Store

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Anthos provides general wellness information only. Nothing in this article constitutes medical advice. Always consult a licensed healthcare professional before making health decisions.