Clearing the Atmosphere

As the days grow shorter and children return to school, autumn brings more indoor time for many of us. According to Health Canada, Canadians spend around 90% of their time inside.

While we often prioritize cold and flu prevention in close quarters during the fall, the quality of indoor air and its impact on our health is frequently overlooked. The US Environmental Protection Agency indicates that indoor pollutant levels can be significantly higher than those found outdoors.

Hidden Threats at Home

“Your immune system doesn’t just combat viruses; it’s also responding to chemicals, mold, airborne particles, and environmental toxins present in your home,” explains naturopathic doctor Alison Danby, who specializes in immune health and autoimmune conditions and hosts the podcast Autoimmune Simplified.

“These seemingly subtle exposures can lead to chronic immune dysregulation and inflammation, weakening your defenses over time.”

According to Danby, the first step to bolstering immune health is to minimize unnecessary immune stress: “The fewer stressors your immune system faces, the more capacity it has to tackle genuine threats like colds and flu.”

Refer to Danby’s guide on identifying hidden household threats and remedies for a robust immune system.

Threat No. 1: Mold

Common Locations: Water-damaged walls, HVAC systems, basements, and poorly cleaned humidifiers.

Effect on Immunity: “Mold can interfere with immune function by disrupting the activity of T and B immune cells, increasing baseline inflammation without infection, and breaking down immune tolerance,” states Danby.

Mold exposure disrupts barrier functions in areas such as the respiratory and digestive tracts, leading to inappropriate immune responses.

Health Risks: Indoor mold and dampness are linked to a higher risk of asthma in young children and increased asthma-related issues in adults. Exposure may cause rhinitis, sinusitis, and irritable bowel disease.

Mold exposure is also connected to the development and worsening of both allergic and nonallergic chronic inflammatory diseases and autoimmune disorders.

Preventive Measures:

• Maintain indoor humidity between 35-50%, using a hygrometer.
• Utilize a dehumidifier in damp areas like basements and bathrooms.
• Clean humidifiers regularly and avoid using them unless necessary.
• Promptly address even small leaks—behind walls, under sinks, and around windows.
• Consider professional inspection and testing.

Threat No. 2: Volatile Organic Compounds (VOCs)

Common Sources: Cleaning sprays, air fresheners, personal care products, paints, adhesives, new furniture, flooring, and scented candles.

Effect on Immunity: “VOCs can prompt the release of inflammatory cytokines (IL-6 and TNF-α), escalate oxidative stress, and hinder immune cells like macrophages and natural killer cells,” states Danby.

Health Risks: VOC exposure is linked to insulin resistance, diabetes, and cardiovascular conditions, likely promoting systemic inflammation and exacerbating upper airway and asthma symptoms.

Preventive Measures:

• Select fragrance-free cleaning and personal care products, EWG-verified, or create your own using vinegar and essential oils.
• Steer clear of air fresheners, fabric sprays, and synthetic candles.
• Choose low- or no-VOC paint and furniture (look for UL GREENGUARD Gold certification or similar).
• Open windows for 10-15 minutes every day to improve ventilation.

Threat No. 3: Nitrogen Dioxide (NO2) and Particulate Matter (PM2.5)

Common Sources: Gas stoves, fireplaces, heaters, cooking oils, candles, and household dust.

Effect on Immunity: “Gas stoves emit nitrogen dioxide (NO2) and fine particulate matter (PM2.5), harming mucosal immunity, reducing natural killer cell activity, increasing airway permeability, and raising inflammatory cytokines (IL-6 and TNF-α),” says Danby.

Health Risks: Inhalation of particulate matter compromises lung function and oxygen levels and can worsen chronic obstructive pulmonary disease and childhood asthma symptoms.

Preventive Measures:

• Always use an exhaust fan or open a window while cooking with gas.
• Consider transitioning to electric or induction cooking if renovating.
• Limit the burning of candles, incense, and wood in indoor stoves.
• Utilize a HEPA and activated carbon air purifier in kitchens and common areas.
• Regularly vacuum with a HEPA-filtered vacuum cleaner.

Threat No. 4: PFAS: Forever Chemicals

Common Sources: Nonstick cookware, stain-resistant textiles, food packaging, cosmetics, and waterproof gear.

Effect on Immunity: “These persistent chemicals accumulate in the body, suppressing antibody production, hindering vaccine responses, and increasing systemic inflammation,” explains Danby.

Health Risks: PFAS can impact the nervous system, disrupt liver, kidney, and thyroid functions, affect body weight and metabolism, and impose risks on reproductive health.

Preventive Measures:

• Substitute nonstick cookware with stainless steel, ceramic, or cast iron alternatives.
• Avoid stain-resistant fabrics, such as couches and carpets treated with Scotchgard.
• Refrain from fast food packaging and microwave popcorn.
• Utilize a reverse osmosis or activated carbon water filter certified to eliminate PFAS.

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