Indoor Air Quality

Indoor Pollutants - Tiny Troublemakers

• Biological Agents:
  • Molds: Damp areas; trigger asthma, allergies.
  • Dust Mites: Bedding, carpets; asthma, eczema.
  • Pet Dander: Animals; allergic reactions.
• Chemical Agents:
  • Volatile Organic Compounds (VOCs): Paints, solvents; irritate eyes, respiratory tract.
  • Formaldehyde ($CH_2O$): Furniture, glues; carcinogen, respiratory irritant.
  • Carbon Monoxide ($CO$): Fuel burning; hypoxia. 📌 Silent Killer.
  • Nitrogen Dioxide ($NO_2$): Gas stoves; ↑ respiratory infections.
  • Lead (Pb): Old paint dust; neurotoxic, affects development.
  • Environmental Tobacco Smoke (ETS): Major risk for SIDS, asthma, LRTI.
  • Radon: Soil gas; lung cancer risk.

⭐ Environmental Tobacco Smoke (ETS) exposure is a significant risk factor for Sudden Infant Death Syndrome (SIDS) and recurrent lower respiratory tract infections (LRTIs) in children.

Pollutant Hotspots - Home Hazards

• Kitchen (Major Source):
  • Biomass fuel (chulha - wood, dung, crop waste): ↑ Particulate Matter (PM2.5, PM10), CO, Polycyclic Aromatic Hydrocarbons (PAHs).
  • Kerosene/LPG stoves (incomplete combustion, poor ventilation): ↑ $NO_2$, CO.
  • 
• Living Areas & Bedrooms:
  • Mosquito coils/liquidators: Pyrethroids, VOCs, smoke.
  • Incense sticks (agarbatti): PM, VOCs (benzene, formaldehyde), CO.
  • Dust mites (mattresses, carpets, upholstery): Allergens (Der p1).
  • Mould/Fungus (dampness, esp. monsoon): Spores, Mycotoxins, MVOCs.
  • Paints, polishes, new furniture/plywood: Formaldehyde, VOCs.
  • Environmental Tobacco Smoke (ETS).
• Other Sources:
  • Cleaning products (phenols, ammonia): VOCs.
  • Pesticides (sprays, chalks).

⭐ Biomass fuel use in poorly ventilated kitchens is a leading cause of indoor air pollution in rural India, significantly increasing risk of acute lower respiratory infections (ALRI) in children < 5 years.

Child Health Hits - Vulnerable Lungs & Brains

• Unique Vulnerabilities:
  • Higher respiratory rate & pollutant intake per kg body weight.
  • Narrower airways, ↑ obstruction risk.
  • Immature immune & detoxification systems.
  • Developing organs (lungs, brain) - critical vulnerability periods.
  • Greater exposure: hand-to-mouth behavior, proximity to floor.
  • Longer life expectancy for chronic effects.
• Respiratory Impacts:
  • ↑ LRTI (pneumonia, bronchiolitis).
  • Asthma: new onset, exacerbations, severity.
  • Impaired lung development, ↓ lung function (e.g., FEV1).
  • Chronic cough, wheezing, allergic rhinitis.
• Neurodevelopmental & Other Impacts:
  • Cognitive impairment (↓ IQ), learning disabilities.
  • ADHD, behavioral problems.
  • Possible links to Autism Spectrum Disorder.
  • SIDS (Sudden Infant Death Syndrome) risk (e.g., from SHS).
  • Otitis Media.

⭐ Exposure to indoor air pollutants like secondhand smoke (SHS) during early childhood is a major risk factor for Sudden Infant Death Syndrome (SIDS), recurrent otitis media, and severe asthma.

Safe Sanctuaries - Clean Air Strategies

• Core Strategy: The 3 Pillars (📌 Mnemonic: SAVE - Source control, Air cleaning, Ventilation, Evaluation/Education)
  • 1. Source Control: Most effective.
    • Ban indoor smoking.
    • Use low-VOC (Volatile Organic Compound) products.
    • Control dampness (target humidity <50%) to prevent mold.
    • Integrated Pest Management (IPM).
    • Test for Radon; mitigate if levels >4 pCi/L.
  • 2. Ventilation: Dilutes & removes pollutants.
    • Natural: Cross-ventilation via windows.
    • Mechanical: Exhaust fans (kitchen/bath), HVAC systems (MERV ≥13 filters).
  • 3. Air Cleaning: Supplements other methods.
    • Portable air cleaners with HEPA filters.

    ⭐ HEPA filters are crucial, removing ≥99.97% of particles ≥0.3 µm (dust, pollen, mold spores, bacteria).

    • Activated carbon for VOCs/odors.
• Maintenance & Monitoring: Regular cleaning, filter changes. Install CO alarms.

High‑Yield Points - ⚡ Biggest Takeaways

• Secondhand smoke (SHS): Major indoor pollutant; linked to SIDS, respiratory infections, asthma.
• Biomass fuel (India): Key risk for ALRI due to indoor combustion (wood, dung) in poor ventilation.
• Carbon Monoxide (CO): Odorless gas from incomplete combustion; causes hypoxia, neurotoxicity. Suspect in unexplained drowsiness.
• Molds & dampness: Trigger allergies, asthma exacerbations, and respiratory issues.
• Volatile Organic Compounds (VOCs) (paints, furnishings): Irritate airways, worsen asthma.
• Lead dust (old paint): Inhalation/ingestion risk for childhood lead poisoning.