The Air Quality Index (AQI) is a 0-500 scale that converts pollutant concentrations — PM2.5, PM10, NO2, SO2, CO, and ozone — into a single number and color-coded category, from Good (green) to Severe (maroon). The Central Pollution Control Board (CPCB) recorded Delhi’s winter AQI exceeding 400 (“Severe”) on multiple days in recent years, a level at which even healthy individuals face respiratory effects, per CPCB’s own health advisory thresholds. Indoor air quality is frequently worse than outdoor air: a commercial office with poor ventilation and CPCB-regulated exhaust can register indoor PM2.5 levels 2-5 times outdoor readings during peak infiltration, according to studies cited by the National Building Code (NBC) 2016 ventilation provisions. A Bengaluru IT park that commissioned an indoor air quality audit after employee complaints found CO2 concentrations exceeding 1,200 ppm in poorly ventilated conference rooms against the ASHRAE-recommended 1,000 ppm ceiling, a fix that cost roughly ₹4-6 lakh in HVAC rebalancing but eliminated the complaints. Understanding where your building’s AQI-relevant readings sit, and what an indoor air quality audit actually measures, is the first step to correcting problems before they show up as absenteeism or compliance flags.
AQI is a 0-500 scale (CPCB, India) with 6 color-coded categories from Good to Severe, based on PM2.5, PM10, NO2, SO2, CO and ozone levels. Indoor air quality audits measure the same pollutants plus CO2 and VOCs inside buildings, typically costing ₹15,000-₹50,000 for a commercial facility.
| City | AQI | PM2.5 | Ozone |
|---|---|---|---|
| New York | 45 | 10 | 35 |
| Los Angeles | 65 | 20 | 45 |
| Beijing | 120 | 80 | 40 |
| Delhi | 200 | 150 | 50 |
In highly populated areas in particular, these emissions may have a negative effect on air quality. Despite their potential to seriously harm human health, indoor air pollution sources are frequently disregarded. Harmful chemicals & pollutants can be released into the air we breathe by cleaning products, tobacco smoke, and building materials, which can result in poor indoor air quality. There are immediate and long-term health consequences associated with exposure to low-quality air.
Breathing difficulties, coughing, and eye, nose, and throat irritation are some of the short-term effects. Although these symptoms are frequently transient, people who already have respiratory disorders may find them especially troublesome. Increased severity of health problems can result from prolonged exposure to air pollution. Long-term exposure to pollutants is frequently linked to respiratory conditions like asthma, bronchitis, and chronic obstructive pulmonary disease (COPD).
Also, there is evidence connecting poor air quality to a higher risk of stroke, heart disease, and even some forms of cancer. Although there may be no way to totally stop someone from being exposed to air pollution, there are things people can do to lessen their exposure and safeguard their health. Refusing to engage in outdoor activities on days with poor air quality is one of the easiest ways to reduce exposure to pollution. Pollution exposure can be reduced by monitoring the AQI and arranging outdoor activities appropriately.
The quality of indoor air can also be increased by using air filters in vehicles and residences. Indoor environments can be made cleaner and healthier by using high-efficiency particulate air (HEPA) filters, which are especially good at removing allergens & fine particles from the air. Another practical strategy for lowering emissions & enhancing air quality is to reduce energy use.
Reducing pollution can be achieved through carpooling, taking public transportation, and conserving energy by using energy-efficient appliances. Evaluating indoor air quality is essential for locating possible pollution sources and implementing the necessary corrective action. People can identify areas of concern and make the necessary adjustments to create a healthier indoor environment by conducting an air quality audit. In the course of an air quality audit, people should look for possible pollution sources in their homes, such as mildew, mold, and chemical emissions from construction materials.
Reducing indoor air pollution can be achieved through regular cleaning, proper ventilation, and the use of natural cleaning supplies. To obtain a more precise estimate of the pollutants present in their homes, people can do air quality tests in addition to conducting an audit. There are several kinds of tests for measuring air quality, such as ones that look at radon gas, volatile organic compounds (VOCs), and particulate matter. One can buy a testing kit or hire an expert to do the test in order to conduct a home air quality test. The test findings will offer insightful details about the particular contaminants found in the indoor environment, enabling focused measures to enhance air quality. If left untreated, a number of common indoor air pollutants can seriously harm human health.
To properly improve indoor air quality, one must comprehend these pollutants and their sources. Common indoor pollutants that proliferate in moist, poorly ventilated spaces are mold and mildew. Those who are sensitive to them may experience allergic reactions and respiratory problems. Mold and mildew growth can be halted with proper ventilation, moisture management, & routine cleaning. Radon gas is a radioactive gas that is found naturally & can enter homes through foundation cracks.
Lung cancer risk can rise with extended exposure to high radon gas concentrations. Keeping an indoor environment free of radon gas requires regular radon gas testing and, if needed, the implementation of mitigation measures. Gas stoves, malfunctioning heating systems, and other combustion appliances can release carbon monoxide, an odorless and colorless gas.
It is possible to die from carbon monoxide exposure at high levels. To avoid carbon monoxide poisoning, carbon monoxide detectors must be installed, and adequate ventilation must be maintained. By eliminating contaminants and guaranteeing a steady supply of fresh air, ventilation & air purification systems are essential for enhancing indoor air quality. There are several varieties of ventilation systems out there, such as balanced, mechanical, and natural ventilation.
In order for stale air to escape and fresh air to enter, natural ventilation depends on apertures like windows and vents. While balanced ventilation combines both natural and mechanical methods, mechanical ventilation circulates air using fans & ducts. Pollutants can be successfully removed from the air by using air purification systems, such as air filters and purifiers. Fine particles, allergens, and other dangerous substances are especially well-captured by HEPA filters. Moreover, activated carbon filters can aid in the airborne removal of chemicals and smells.
To preserve a healthy environment and stop pollution’s harmful effects on human health, air quality monitoring and improvement are essential. People can significantly improve their own health & the general quality of the air in their communities by learning about the AQI scale, locating the sources of air pollution, and taking action to reduce exposure. The general health & quality of the air can be greatly improved by making small adjustments like using air filters, cutting back on energy use, and avoiding outdoor activities on days with high pollution. We can give ourselves and future generations a healthier & more sustainable future by acting to improve the quality of the air.
If you’re interested in learning more about air quality and its impact on industrial settings, you should check out this informative article on common applications of thermography audits in industrial settings. This article discusses how thermography audits can be used to assess and improve air quality in various industrial environments. It provides valuable insights into the benefits of using thermography audits to identify potential air quality issues and implement effective solutions. To read the full article, click Common Applications of Thermography Audits in Industrial Settings.
FAQs
Q1: What is considered a good Air Quality Index (AQI) in India?
Answer: According to the Central Pollution Control Board (CPCB), an AQI of 0–50 is classified as “Good”, while 51–100 is “Satisfactory.” Air quality is considered Poor above 200, Very Poor above 300, and Severe above 400. During severe AQI conditions, even healthy individuals are advised to limit prolonged outdoor activities due to increased health risks.
Q2: How much does an indoor air quality (IAQ) audit cost in India?
Answer: The cost of an indoor air quality audit typically ranges from ₹15,000 to ₹50,000 for commercial buildings, depending on the floor area, number of sampling locations, and parameters measured. A standard assessment generally includes monitoring of PM2.5, PM10, carbon dioxide (CO₂), volatile organic compounds (VOCs), temperature, humidity, and ventilation performance.
Q3: How often should indoor air quality be tested?
Answer: Indoor air quality should generally be tested once every year in commercial offices and institutional buildings. Facilities such as hospitals, laboratories, pharmaceutical plants, and buildings located near industrial areas should ideally conduct IAQ assessments every six months or whenever significant renovations, HVAC modifications, or occupant health complaints occur.
Q4: What is the difference between AQI and indoor air quality testing?
Answer: Air Quality Index (AQI) measures outdoor ambient air pollution using data from CPCB monitoring stations and reflects pollution levels over a wider geographic area. Indoor air quality (IAQ) testing is a building-specific assessment that measures pollutants such as particulate matter, CO₂, VOCs, temperature, humidity, and ventilation effectiveness inside a facility. Outdoor AQI does not accurately represent the air quality experienced inside buildings.
Q5: What are the most common causes of poor indoor air quality in offices?
Answer: Common causes of poor indoor air quality include insufficient fresh-air ventilation, poorly maintained HVAC systems, excessive recirculation of indoor air, emissions from furniture, carpets, paints, and office equipment, infiltration of outdoor pollution through building openings, and inadequate filtration. Regular HVAC maintenance and periodic IAQ assessments help identify and address these issues before they affect occupant health and productivity.