be responsible for 7 million premature deaths or 7.7% of total mortality according to latest updates by WHO and mainly affects vulnerable populations such as women and children. The United Nations’ Global Millennium Development Goals have advocated clean household energy and reduced solid fuel use for lowering indoor air pollution and associated respiratory illness. Health impacts of indoor air pollutants range from acute to chronic respiratory diseases including lung cancer, asthma, pneumonia, tuberculosis extending to cardiovascular diseases such as stroke. Thus, household air pollution is a significant factor affecting quality of indoor air and health of occupants.
- This problem of poor IAQ is echoed in developed countries as well where studies have shown that IAQ significantly affects health, productivity and performance of building occupants. Indoor air quality issues have arisen in commercial buildings in recent times due to higher incidences of poor outdoor air quality (e.g. smog) and a focus on energy efficiency which has led to tighter building envelopes, inoperable windows, moisture retention in building envelope assemblies and less outside air entering in, that can dilute contaminants. Combustion appliances, building products (such as composite wood, paints and coatings, adhesives and sealants, and insulation), furniture,tobacco smoke, cleaning products, toner from printers, air fresheners, adhesives used in building materials, moisture, and occupants are some of the main indoor and outdoor sources of indoor air contamination . Historically, building related complaints or disorders were classified either as sick building syndrome (SBS) or building related illnesses (BRI). In both cases, the occupants were found to be spending significant amounts of time inside poorly ventilated buildings. While SBS represents a primary and more generalized unwell syndrome of acute health or comfort related effects, BRI is recognized as a more specific set of symptoms attributable to indoor environments. For example, SBS symptoms include disorders such as headaches, dizziness, dry throat, cough, watery eyes, etc. while BRI includes more defined, serious diseases such as Legionnaire’ s disease, allergic alveolitis, pneumonia, occupational asthma and even certain cancers. Poor indoor air quality has been found to be closely associated with both SBS and BRI. Indoor air quality also depends on factors such as indoor temperature, humidity, levels of gases such as carbon dioxide (CO2) and carbon monoxide (CO), volatile organic compounds (VOCs), particulates, ozone, presence of noxious odors and irritants in tobacco smoke, dust, etc. VOCs particularly are chemicals of concern for exposure, and they include known or probable human carcinogens, reproductive/developmental toxins, and systemic toxins with non-cancer chronic effects.
- Along with chemical origin factors, biological factors such as mold and moisture may be associated with respiratory health effects on occupants. Microbial agents (bacteria and spore forming fungi) thrive in conditions of high humidity, non-circulating air and trapped heat inside building spaces and create mycotoxins and endotoxins that may affect occupant health. Not only that, mold and moisture also decrease efficiency of building infrastructure specifically envelope assemblies. It is now known that better IAQ reduces sick building symptoms of building occupants by 20-50%, incidence of asthma by 8-25%, and other respiratory illnesses by 23-76%, leading to a total estimated savings of about $100 billion. IAQ also has an effect on worker performance- IAQ indicators such as CO2 and VOCs in indoor air, and building ventilation rates have significant, independent impacts on employee cognitive functions, which in turn affect productivity and performance. The ultimate adverse consequence of poor Indoor Air Quality, thus, is on the very output of the companies that occupy such buildings that have poor Indoor Air Quality. Therefore, optimum Indoor Air Quality is of prime importance in today’s time. Design strategies such as increasing ventilation rates by 10 L/s-person have been shown to result in 1-3% average performance improvement, and removing IAQ pollutant sources leads to a 4% improvement in work performance. Therefore, to improve the quality of the air we breathe has become of utmost importance. But, in order to breathe healthy and safe oxygen, one must first check the parameters that are polluting the pristine quality of our natural air.
