Clear the Air

“Your immune system isn’t just fighting viruses—it’s reacting to chemicals, mold, airborne particles, and environmental toxins that build up in your home environment,” says naturopathic doctor Alison Danby. Danby has a virtual practice focused on immune health and autoimmune conditions, and hosts the podcast Autoimmune Simplified.

“These exposures may seem subtle, but they contribute to chronic immune dysregulation, inflammation, and weakened defence over time.”

Danby says that the first step in supporting immune health is reducing unnecessary immune stress: “The more immune stressors you eliminate, the more bandwidth your immune system will have to fight real threats, like cold and flu.”

Follow Danby’s guide on hidden household threats and remedies for a resilient immune system.

Threat No. 1: Mold

Found in: water-damaged walls, HVAC systems, basements, and poorly cleaned humidifiers.

Impact on immunity: “Mold disrupts immune function by dysregulating T and B immune cell activity, increasing baseline inflammation without infection, and breaking down immune tolerance,” says Danby.

Mold exposure also disrupts barrier functions in places like the respiratory and digestive tracts, resulting in an inappropriate immune response.

Health consequences: Indoor mold exposure and dampness are associated with an increased risk of developing asthma in young children, and increased asthma morbidity in adults already suffering from the condition. Exposure is associated with rhinitis, sinusitis, and irritable bowel disease.

Mold exposure is also associated with the development and exacerbation of allergic and nonallergic chronic inflammatory diseases and autoimmune disorders.

Remedy:

• Keep indoor humidity between 35 and 50 percent, measured by hygrometer.
• Use a dehumidifier in damp areas (basements, bathrooms).
• Clean humidifiers daily/weekly, and avoid them unless truly needed.
• Address even minor leaks immediately—behind walls, under sinks, and around windows.
• Consider professional inspection and testing.

Threat No. 2:Volatile organic compounds (VOC)

Found in: cleaning sprays, air fresheners, personal care products, paints, adhesives, new furniture, flooring, and scented candles.

Impact on immunity: “VOCs trigger the release of inflammatory cytokines (IL-6 and TNF-α), increase oxidative stress, and impair immune cells like macrophages and natural killer cells,” says Danby.

Health consequences: Exposure to VOCs is associated with insulin resistance, diabetes, and cardiovascular disease, and likely promotes systemic inflammation. High VOCs are associated with upper airway and asthma symptoms.

Remedy:

• For cleaning and personal care products, choose fragrance-free, EWG-verified, or make your own with vinegar and essential oils.
• Avoid air fresheners, fabric sprays, and synthetic candles.
• Opt for low- or no-VOC paint and furniture (look for UL GREENGUARD Gold or similar certifications).
• Open your windows for 10 to 15 minutes a day.

Threat No. 3:Nitrogen dioxide (NO2) and particulate matter (PM2.5)

Found in: gas stoves, fireplaces, heaters, cooking oils, candles, and dust.

Impact on immunity: “Gas stoves release nitrogen dioxide (NO2) and fine particulate matter (PM2.5), which damage mucosal immunity, impair natural killer cell activity, increase airway permeability, and raise inflammatory cytokines (IL-6 and TNF-α),” says Danby.

Health consequences: Inhaling particulate matter affects lung function and oxygen saturation, and is associated with an aggravation of symptoms of chronic obstructive pulmonary disease and childhood asthma.

Remedy:

• Always use an exhaust fan or open a window when cooking with gas.
• Swap to electric or induction if renovating.
• Minimize burning candles, incense, and indoor wood-burning stoves.
• Use a HEPA- and activated-carbon air purifier near the kitchen or common areas.
• Vacuum regularly with a HEPA-filtered vacuum.

Threat No. 4: PFAS: Forever chemicals

Found in: nonstick cookware, stain-resistant textiles, food packaging, cosmetics, and waterproof gear.

Impact on immunity: “These persistent chemicals accumulate in the body and suppress antibody production, interfere with vaccine response, and increase systemic inflammation,” says Danby.

Health consequences: PFAS may affect the nervous system; alter the functioning of the liver, kidney, and thyroid; impact bodyweight and metabolism; and affect reproductive function.

Remedy:

• Replace nonstick pans with stainless steel, ceramic, or cast iron.
• Say no to stain-resistant fabrics (like Scotchgard-treated couches and carpets).
• Avoid fast-food packaging and microwave popcorn.
• Use a reverse osmosis or activated carbon water filter certified to remove PFAS.

This article was originally published in the September 2025 issue of alive magazine.