Indoor air quality refers to the quality of air inside and around buildings as it related to human health. Poor indoor air quality can cause both long- and short-term health effects, and causes what’s known as “sick building syndrome” in those with prolonged exposure to poor quality air.
Low building ventilation, high concentrations of VOCs, and indoor mold can all contribute to sick building syndrome. It can cause headaches, nausea, respiratory infections, and stress-like symptoms (often mistaken for work stress in office buildings). Chemical and biological contaminants, like VOCs, can all contribute to poor health of those who work in poorly ventilated areas. Essentially, poor indoor air quality can cause general and specific health
Volatile organic compounds are organic chemicals that evaporate and become vapour at very low temperatures (a trait called volatility). Things like exhaust gas, formaldehyde, nail polish remover, and many smells are VOCs. Exposure to some VOCs cause allergic or irritation reactions like runny noses, throat irritation or headaches. In some cases, reactions can be extreme - numbness, dizziness, nausea, fainting. The degree of the reaction depends on the length and intensity of exposure, as well as the specific VOCs involved.
A hydroxyl radical is a reactive molecule formed by one oxygen and one hydrogen. They react (oxidise) extremely easily with almost all of the chemicals found in our troposphere. This removes these chemicals from the air - the oxidation of these chemicals results in water and organic radicals, which an extremely important part of the ozone formation cycle. Essentially, hydroxyl radicals scrub VOCs and other harmful substances from our air, and leave important organic compounds in their place.
Hydroxyl radicals are formed naturally in our atmosphere through the sun’s radiation and water vapour, and react almost immediately after they’re formed. This is often why hydroxyl radicals aren’t found indoors - they usually react before they can get there.