Air Indoors and in Confined Spaces Often Worse Than Outdoor Air

We often take in-door air quality even though it has pollutants from outside and those released indoors.

- DR P.S. VENKATESH RAO

The Air Quality Index (AQI) measures eight primary air pollutants: particulate matter (PM2.5 and PM10), ozone (O3), carbon monoxide (CO), nitrogen dioxide (NO2), sulphur dioxide (SO2), lead (Pb), and ammonia (NH3). Accumulation of these and many other indoor pollutants often makes the air in enclosed spaces worse than outdoor air. Dusting and sweeping instead of vacuuming increases particulate matter in indoor air. Carpets, linen, furnishings, and fixtures accumulate dust and allergens. Humidity encourages the formation of mold spores. Smoking, cooking, and heating with polluting fuels, as well as lighting candles and oil lamps, consume oxygen and release pollutants. Numerous commonly used items release toxic chemicals. Inadequate indoor ventilation and inefficient removal of dust, food particles, pet dander, dust mites, allergens, microbes, pests, and pollutants trigger allergy and breathing problems and contribute to respiratory infections, asthma, lung cancer, and other health issues.

VOCs and CECs: The World Health Organization (WHO) considers indoor air pollution "the world's largest single environmental health risk". Various indoor activities and substances can contaminate the air, rendering it more hazardous than polluted outdoor air. Volatile organic compounds (VOCs) such as benzene, toluene, xylene, and formaldehyde found in various indoor products and processes, including paints, cleaning products, fuels, and aerosols, readily evaporate at room temperature. They react with nitrogen dioxide and ozone from outside vehicle exhaust to form toxic compounds. VOCs can cause eye, nose, and throat irritation, headaches, and in some cases, damage to the liver, kidneys, or central nervous system. Some VOCs are suspected or proven carcinogens.