When we think of air pollution, we are most likely to think of thousands of cars stuck in the traffic, giant industrial chimneys and cities blinded by heavy smog. However, we are not often aware that the air quality in our homes can sometimes be worse than the air quality outside. According to the United States Environmental Protection Agency (EPA), the levels of indoor air pollutants are often 2 to 5 times higher than outdoor levels, and occasionally these levels can exceed 100 times that of outdoor levels of the same pollutants.
How is indoor air pollution different?
The air that occupies our living rooms, bedrooms, offices, closed public places, and interiors of a public transport are often contaminated by pollutants such as Volatile Organic Compounds (VOCs), combustion byproducts (Carbon Monoxide, Indoor Particulate matter, Secondhand smoke and smoke from cookstoves and heaters) and biological pollutants. On the other hand, outdoor air pollution are emissions caused by motor vehicles and factories. Other pollution sources include smoke from bushfires, windblown dust, and biogenic emissions from vegetation (pollen and mold spores).
Since we humans spend a large amount of time indoors for both work and leisure, poor indoor air quality is going to affect our lungs, heart and induce other various illnesses. Since the spread of the COVID-19, it has become even more necessary that we pay attention to the quality of our indoor air because research tells us that the virus can latch itself to particle pollutants making it more transmissible. This adversely affects business and the wider economy as closed office spaces and factory units with poor indoor air quality become a hotspot from the spread of the virus.
Outdoor Air Pollution also contributes to poor Indoor Air Quality
Our homes are not necessarily designed to protect us from harmful natural elements, such as outdoor air pollution. Since we spend most of our time indoors and frequently at home, exposure to air pollution is also a constant worry. Infiltration of outdoor air pollutants is a significant cause of air pollution in homes, in addition to indoor emissions from chores like cooking and cleaning. Open windows and doors, supply air ventilation systems, and other openings allow outdoor air pollution to enter buildings as a result of pressure and temperature changes.
Measuring Outdoor Air Quality
The Air Quality Index (AQI) is used to measure outdoor air quality. The AQI has a yardstick that runs from 0 to 500. The higher the AQI value, the greater the level of air pollution and the greater the health concern. For example, an AQI value of 40 or below represents good air quality, while an AQI value over 250 represents poor air quality.
Different countries have their own air quality indices, according to different national air quality standards. In India, the AQI considers eight pollutants: PM10 (Particulate matter 10), PM2.5 (Particulate matter 2.5), NO2 (Nitrogen Dioxide), SO2 (Sulfur Dioxide), CO (Carbon Monoxide), O3 (Ozone), NH3 (Ammonia) and Pb (Lead).
Measuring Indoor Air Quality
Indoor Air Quality (IAQ) is measured and monitored by taking into consideration factors such as the presence of carbon dioxide, particulate matter concentrations (PM 2.5 and PM 10) and chemical pollution (VOCs) concentrations. Portable sensors are deployed in the rooms for a few hours. These are equipped with technology to detect the presence of various pollutants in the air. After the evaluation, the user receives a detailed report telling them various levels of indoor air pollutants. The user then further speaks with experts to know ways on how to improve indoor air quality.
Overcoming Indoor Air Pollution and Outdoor Air Pollution: Two different strategies
It is difficult to overcome the challenge of outdoor air pollution without effective public policy. All stakeholders, both public and private, are required to join hands in introducing measures that will guarantee all safe air to breathe. For starters, it is important to improve public transport systems across all cities so that people prefer it over using private vehicles that cause carbon emission. Further, our cities should increasingly move towards green energy. Public spaces should be reoriented in order to adopt cleaner technologies instead of fossil powered generators. Construction work must be regulated well in order to control dust pollution. An important step to effectively implement such policies is to monitor and collect data about outdoor air pollutants.
On the other hand, improving indoor air quality requires high performance ventilation systems. Our buildings must also be equipped with appropriate technology that aids the removal of indoor air pollutants. For instance, there are mainly three types of air filters that are installed for tackling indoor air pollution - Pre Filters, HEPA Filters and Carbon Filters. The best air cleaners have HEPA filters installed in them. These filters are meant to pull out the small pollutants from indoor air.
It is important to note that concentration of pollutants indoors will vary from house to house even if they are within the same neighborhood because of different lifestyles, behaviors, and practices. Understanding Indoor air pollution is complicated and solutions are never one size fits all. We should treat IAQ evaluations like timely health checkups for your homes. With the lasting impacts of polluted air on our health, it is important to know the quality of air we breathe.
