Air Quality Index Explained: Howe Toxic Air Threatens Heart Health and Brain Function

On Sunday, Delhi's air quality was recorded in the severe category, prompting authorities to impose the GRAP-IV measures. On Monday and Tuesday, it worsened further, reaching the severe plus category, with the AQI exceeding 450.

On Monday, Citizens of Delhi breathed in the air considered as smoking 49.02 cigarettes every day.

As per the Central Pollution Control Board (CPCB), the air quality reached an uncommon new high, as of 18 November: Anand Vihar: 500, Vivek Vihar: 498, Chandni Chowk: 480.

Due to such severe air pollution, the public is unknowingly exposed to severe health risks.

But what is AQI?

And what actually happens to humans when people are exposed to menacing levels of air pollution?

The Air Quality Index (AQI) is a system designed to monitor the levels of five key air pollutants: ground-level ozone, particulate matter (PM), carbon monoxide, nitrogen dioxide, and sulfur dioxide. this system was established by the Environmental Protection Agency (EPA) and offers a daily overview of air quality to help people assess potential health risks.

An AQI between 0 and 100 indicates air that is generally safe to breathe, with little to no health risk. However, when the AQI surpasses 100, sensitive groups may begin to experience health effects, and levels above 200 pose significant health risks for everyone.

Recently, the average AQI in Delhi ranged from 450 to 500.

Dr. Arup Halder, a senior pulmonologist at CMRI Hospital, told Business Standard that when the AQI worsens, it allows pollutants to enter the body through the lungs, which affects various organs in the process. Early symptoms may include mild issues like headaches, nasal congestion, and skin irritation, but prolonged exposure can lead to severe health conditions. Over time, breathing polluted air increases the risk of chronic respiratory diseases such as asthma, chronic obstructive pulmonary disease (COPD), and even lung cancer.

Dr. Halder further explains that ultra-fine particulate matter, smaller than 0.1 microns, can enter the bloodstream through the lungs, causing widespread systemic effects. These tiny particles can harm not only the lungs but also the heart, brain, kidneys, and other organs. For example, air pollution is linked to conditions such as hypertension, ischemic heart disease, and heart attacks, particularly in colder months. Research also indicates that these particles can affect the brain, contributing to cognitive decline, dementia, and strokes, especially in older adults. In children, prolonged exposure may impair neurological development.

Air pollution has significant impacts on various systems in the body. In the respiratory system, it can trigger or worsen conditions like asthma, allergic rhinitis, COPD, and lung cancer. Additionally, it raises the risk of acute illnesses, including pneumonia and other lung infections.

Apart from that, air pollution significantly affects the cardiovascular system, increasing the risk of heart disease. The fine particulate matter has been linked with heart attacks, strokes, heart failure, and hypertension. Cognitive health also suffers, with pollution linked to early cognitive decline, dementia, and Alzheimer’s disease.

The skin is similarly vulnerable, with exposure contributing to conditions such as dermatitis, eczema, and premature aging. Even internal organs like the kidneys and liver are at risk, as air pollution may contribute to chronic kidney disease and liver damage.

Certain groups are particularly vulnerable to the harmful effects of air pollution, and even brief exposure to high AQI levels can cause lasting damage. Pregnant women, for instance, face heightened risks, as air pollution can interfere with placental development, impair fetal growth, and trigger long-term epigenetic changes in the child. These changes can increase the likelihood of various diseases later in life, highlighting how many adult health issues can be traced back to environmental exposures during early development.

The most impactful solution would be a fundamental shift in government policy. However, on an individual level, there are steps you can take to protect yourself and your family. Stay indoors whenever possible, and consider using a portable air cleaner or purifier if available.

Avoid activities like smoking and frying foods, as both contribute to indoor air pollution. The effects of poor air quality on the body are extensive and complex. As AQI levels worsen, it is vital to acknowledge both the immediate and long-term health risks of air pollution, emphasizing the urgent need for stronger measures to reduce pollution and protect public health.