Indoor Air Quality: Delhi’s air quality came dangerously close to the severe category on Friday. Most of the monitoring stations in the capital recorded the air quality index (AQI) level above 400. According to Central Pollution Control Board (CPCB) data, the overall AQI of the city at 6 am was 384, which is in the very poor category. Of the 39 monitoring centers across the city, 19 recorded pollution in the severe category. The situation was worse in Noida, where almost all the centers recorded the AQI in the severe category.
indoor air pollution
In comparison, the difference between indoor and outdoor air pollution does not seem that severe. But research shows that indoor and outdoor air pollution are deeply interconnected. Understanding the relationship between indoor and outdoor air quality is your strongest weapon against the effects of pollutants on your health. Both your behavior and the environment influence the interaction between indoor and outdoor pollutants. So it is important to change both your habits and your home to reduce the impact of outdoor air pollution on indoor air.
Is indoor air more polluted than outside air? Indoor air quality can be more dangerous than outdoor air pollution. Because it affects you in those places where you spend 80 percent or more of your time every day. Outdoor air pollution coming into the house can reach extremely high concentrations. A study found that people spend about 87 percent of their day in homes or buildings and 6 percent in closed vehicles. Multiple reports from the U.S. Environmental Protection Agency (EPA) have shown that indoor air pollution levels in homes, offices, and school classrooms are typically 2.5 times higher than outdoor pollution levels and can quickly become ten times worse than outdoor air pollution.
Which elements cause air pollution?
But why is indoor air quality more lethal than outdoor air pollution? First, know that outdoor air pollution typically includes the following pollutants:
PM10: Particles smaller than 10 microns, such as dust, pollen and mold (for example, a human hair is 50-70 microns in size). Many outdoor PM10 particles have natural sources, such as construction and agricultural activities.
PM2.5 : Particles smaller than 2.5 microns. Most outdoor PM2.5 is produced by human activities such as vehicle exhaust, factory exhaust fumes, and smoke from the burning of wood and biomass fuels. PM2.5 is also a major component of wildfire smoke.
Ultrafine particles: Ultrafine particles (UFP) are less than 0.1 micron in diameter. These microscopic particles can pass through the lung tissue and enter the bloodstream and almost every organ of the body.
Ozone: Underground ozone (O3), often simply called smog, is produced by the reaction of heat with low-level pollutants in the atmosphere. Gases from vehicles and industrial processes, such as nitrogen oxides and volatile organic compounds, are the most common sources of ozone. The concentration of these external pollutants continuously increases and decreases due to changes in weather, climate and human activities. For example, due to temperature inversion, external pollutants can accumulate in the lower atmosphere. This happens during cold weather when warm air rises into the upper atmosphere and traps cold air below it, causing pollutants to accumulate at lower altitudes.
naturally purifying air
The concentration can increase rapidly even during morning rush hour. But when there is less traffic, this concentration is reduced by cleaning the air by spreading additional pollutants through the air flow due to wind and heat and allowing them to rise into the atmosphere. In this sense, the Earth has its own natural air-purification technology which spreads external pollutants far and wide. This helps in maintaining the concentration of air pollution at a relatively safe level in most parts of the world. But similar processes are not always used to reduce the concentration of indoor air pollutants. Ventilation can bring in fresh outdoor air to dilute indoor pollutants, but polluted outdoor air can also bring even more pollutants into your home.
open windows and doors
When your house or building feels stuffy, your first reaction may be to open windows and doors to let in fresh air. But when levels of outdoor pollutants and the air quality index are high, indoor air pollution can be even worse. In such a situation, by keeping the windows closed, the air quality inside the house can be better than the outside air quality. In general, regular ventilation of plenty of outdoor air is recommended to reduce the concentration of indoor pollutants and toxic gases, such as particulate matter and carbon dioxide. But when polluted outdoor air enters your home or office in such large quantities, your risk of exposure to outdoor PM10 and PM2.5 increases significantly.
wear a mask outside
People have stopped wearing masks while going out because they feel that it is no longer needed. But in places with high AQI, masks can become an essential means of protection from inhaling dust, fine particles and dangerous chemicals. Walking outside even for short periods of time in contaminated areas can expose you to high amounts of pollutants, so wearing a mask is a sensible precaution.
