Urban Air Pollution & Chronic Lung Diseases in India: A Quick Survival Guide

Pollution in India is an emergency threatening public health. The changing seasons affect air quality, creating a recurring cycle of health problems for millions of people living in urban areas. Seasonal air quality leads to chronic respiratory health problems, from the heavy winter smog in the North of India to the warm, humid, dusty air in coastal metropolitan areas.

From pre-existing conditions like asthma, COPD, and allergic rhinitis, the seasonal changes in air quality represent life-threatening triggers. These seasonal changes are of great importance to patients who have experienced and suffered them, as they are the most severely affected.

The Winter Crisis: The Quality of Air in North India

The winter season in North India, predominantly in the Indo-Gangetic Plain, is synonymous with perilous air quality. With the descending temperatures, wind speed also lessens, which leads to pollutants becoming trapped close to the surface, a situation known as the temperature inversion phenomenon.

Effects on Asthma and COPD in the Delhi National Capital Region

The winter pollution crisis predominantly affects Delhi NCR. In the prominent months, which are from November to January, the AQI surpasses the severe category like clockwork.

Patients with asthma or Chronic Obstructive Pulmonary Disease (COPD) suffer bronchiolitis due to inflammation from particle matter, measuring 2.5 micrometers or less (PM2.5), which permeates and gets trapped in the pulmonary system. Emergency departments in Delhi experience a documented increase in the range of 20-30% in the months of PM2.5 peak concentration events due to the rise in cases of respiratory distress related to acute wheezing and chest discomfort.
  

Burning Biomass and Toxic Smog  

Burning crop residue in the nearby states of Punjab and Haryana significantly contributes to the air pollution during the winter months. The north-westerly winds transport the smoke to Delhi and the surrounding cities, which are loaded with carbon monoxide, polycyclic aromatic hydrocarbons (PAHs), and PM2.5. It has the potential to cause chronic respiratory distress and is a significant trigger for respiratory distress, chronic eye irritation, and lung function declines.
  

Seasonal Changes: Specific Triggers of PM2.5  

Winter is the peak season for air pollution in India, although pollution is a cross-cutting challenge throughout the year, with seasonal spikes causing distinct health effects.  

Chronic Bronchitis and PM2.5 Convergence  

Seasonal PM2.5 levels and rates of chronic bronchitis also display a high degree of correlation.  

Winter: Peak PM2.5 levels due to the increase in biomass burning and temperature inversions.  

Summer: PM10 levels due to coarse dust increase, and vehicular emissions contribute to PM2.5 levels.  

Monsoon: The rain refreshes the area, cleansing the air of particulates.

The critical October/November and February/March transitions are most important. With drops in temperature and increases in PM2.5, one can develop “seasonal bronchitis,” resulting in a persistent cough and bronchial mucus.

The Diwali Spike: Sulfur Dioxide and Asthma

Air quality during Diwali is crucial. Firework shows emit a mixture of heavy metals, and sulfur and nitrogen dioxide.

In patients with bronchial asthma, the sulfur dioxide acts as a bronchial spasmogen. During the festival, the rate of hospital admissions due to acute asthma exacerbations doubles in the two days following. The heavy fog isn’t just an annoyance. It can lead to exacerbations that require a higher dosage of steroids to manage for a prolonged period.

Viral Infections and Post-Monsoon Allergens

As the monsoon withdraws, the humidity that remains, along with the cooling temperatures, is perfect for the overgrowth of both mold and fungi. The collection of moisture and dust particles on the road also increases. Biological and chemical allergen exposure triggers a higher incidence of Acute Respiratory Infections (ARIs), including viral fevers and upper respiratory tract infections.

Regional Analysis: Coastal Metros vs. The Hinterland

The effects of air pollution on the body vary by geography and prevailing weather patterns.

Increasing Pollution in Coastal Cities (Mumbai & Kolkata)

The “sea breeze” effect was once believed to help coastal cities avoid the worst of pollution, but recent evidence suggests otherwise.

Mumbai: High levels of dust pollution result from heavy construction and vehicular traffic. During recent winters, Mumbai’s AQI has surpassed Delhi’s, and there has been an increase in allergic bronchitis.

Kolkata: High population numbers and particular geography trap diesel exhaust. There has been an increase in hospitalizations for lower respiratory tract infections, especially among elderly patients.

Triggers of COPD in South India (Bengaluru & Chennai)

Compared to most other Indian cities, South Indian cities enjoy better AQI due to less stubble burning and better air circulation. But the management of COPD is different.

The primary cause in the South is high humidity plus vehicular emissions. In contrast to North Indian patients, who have to deal with cold smog, southern patients experience humidity-induced chest tightness and mold sensitivity. Here, management focuses more on the allergic triggers and humidity than on the chilly air.