Delhi's Urban Pollution: Impact On Health And Wellbeing

Delhi, the capital territory of India, has been deemed the city with the worst air quality of any major city in the world. The air pollution in Delhi affects the health of its residents in a multitude of ways, with the poor and marginalised suffering disproportionately.

The air quality index (AQI) in Delhi is often in the 'poor to severe' range, with the air containing particulate matter (PM)10, PM2.5, nitrogen dioxide, sulphur dioxide, carbon monoxide, ozone, ammonia, and lead. The PM2.5 in particular is extremely small, with the largest of these particles being 30 times thinner than human hair, and can travel to the deeper parts of the lungs.

The sources of air pollution in Delhi are varied, with vehicles being a major contributor, along with stubble burning in neighbouring states, industrial activities, and construction. The cold air in winter, combined with slow wind speed and a lack of rain, further exacerbates the problem by trapping pollutants close to the ground.

The effects of air pollution on health are wide-ranging, with almost every organ in the body potentially impacted. Respiratory issues, such as asthma, are common, and air pollution has also been linked to cardiovascular issues and cancer. A study found that the air pollution in Delhi has irreversibly damaged the lungs of 2.2 million children.

Overall, the poor air quality in Delhi has severe consequences for the health and well-being of its residents, highlighting the urgent need for effective measures to reduce pollution levels.

The health impacts of air pollution in Delhi

Air pollution in Delhi, India, is a severe issue that has been deemed a health emergency by the Central Government of India. The city's poor air quality has been linked to a range of adverse health effects on its residents, especially the most vulnerable populations. Here is an overview of the health impacts of air pollution in Delhi:

High Pollution Levels

Delhi's air quality is often rated as "poor" or "severe," with particulate matter (PM) levels far exceeding the acceptable limits set by the World Health Organization (WHO). The air quality index (AQI) in Delhi frequently falls within the hazardous category, with levels of PM2.5 and PM10 particulate matter reaching multiple times the recommended limits. These tiny particles can enter the lungs and cause a host of respiratory and cardiovascular issues.

Respiratory Problems

Air pollution in Delhi has been associated with increased respiratory problems among its residents. Studies have found higher rates of respiratory symptoms such as dry cough, wheezing, breathlessness, and chest discomfort in the city's population compared to control groups. Lung function tests have also shown reduced lung capacity and increased prevalence of restrictive and obstructive lung defects in Delhi residents. The high levels of air pollution have been linked to increased cases of asthma, bronchitis, and other respiratory infections.

Cardiovascular Issues

In addition to respiratory problems, air pollution in Delhi has been linked to cardiovascular issues. Studies have found associations between increased air pollution levels and higher rates of hypertension, heart disease, and stroke. The fine particulate matter in the air can enter the bloodstream and contribute to systemic inflammation, affecting the heart and blood vessels.

Cancer Risks

Long-term exposure to air pollution in Delhi has been identified as a risk factor for cancer, particularly lung cancer. The high levels of particulate matter and other pollutants can damage lung tissue and increase the risk of cancer development over time.

Adverse Effects on Children

Children are especially vulnerable to the health impacts of air pollution in Delhi. Studies have shown that air pollution can lower children's immune systems and increase the risks of respiratory issues, asthma, and even adult-onset diseases. Children spend more time outdoors and are, therefore, more exposed to the harmful pollutants in the air. Delhi's poor air quality has been found to cause irreversible lung damage in millions of children.

Other Health Issues

Air pollution in Delhi has also been linked to a range of other health issues, including eye and skin irritation, headaches, sore throats, and fatigue. Prolonged exposure to high levels of air pollution can also lead to reduced life expectancy and increased risk of early death.

Seasonal Variations

The role of stubble burning in Delhi's air pollution

Delhi, the capital territory of India, has been deemed the city with the worst air quality of any major city in the world. The air pollution in Delhi has been found to cause serious respiratory issues and irreversible lung damage in children.

Stubble burning in northern India has been a major cause of air pollution in Delhi. Farmers in states like Punjab, Haryana, and Uttar Pradesh burn crop stubble to clear fields after the harvest. This practice releases massive amounts of smoke and harmful particles into the air, which are then carried into Delhi by winds, significantly worsening the levels of pollution. The smoke from stubble burning is likely to travel as far as Delhi, adding to the national capital's toxic haze.

The contribution of stubble burning to Delhi's air pollution has been a topic of debate. Some studies and government reports have suggested that stubble burning accounts for a small percentage of Delhi's air pollution, with figures ranging from 4% to 7%. However, other sources and experts argue that these numbers do not tell the full story. The share of stubble burning in Delhi's pollution can vary significantly, ranging from 1% to 42%, depending on wind speed and direction. A recent government report also indicated an increase in the average contribution of stubble burning to Delhi's air pollution, from 10% in 2019 to 15% in 2024.

The impact of stubble burning is further exacerbated by weather conditions. Farmers typically burn stubble twice a year, and the second time, in September or October, when temperatures drop and wind speeds are low, the smoke spreads far and wide, affecting a larger area.

While stubble burning is not the sole cause of Delhi's air pollution, it is a significant contributor, especially during certain times of the year. Other factors, such as dust, industrial and vehicular emissions, and incineration, also play a role in Delhi's poor air quality.

The impact of meteorological factors on Delhi's air quality

Delhi, the capital territory of India, has been found to have the worst air quality of any major city in the world. The air pollution in Delhi affects the health of its residents in numerous ways.

Meteorological factors such as cold weather and stagnant winds play a significant role in exacerbating Delhi's air pollution. During the winter months, cold weather causes the air to be frozen and still, trapping pollutants like smoke, dust, and factory emissions near the ground. This accumulation of pollutants leads to the formation of smog, which reduces air quality and poses health risks to residents.

The combination of meteorological conditions and human activities contributes to the poor air quality in Delhi, with serious consequences for public health.

The sources of air pollution in Delhi

Delhi, the capital territory of India, has been found to have the worst air quality of any major city in the world. The air pollution in Delhi is estimated to kill about 2 million people every year and is the fifth-largest killer in India.

Sources of Air Pollution in Delhi

• Vehicular emissions: According to a 2018 research paper by India's Ministry of Earth Sciences, vehicular emissions account for almost 41% of air pollution in Delhi. The number of vehicles on Delhi's roads is increasing due to a lack of sufficient public transport options, leading to constant traffic jams and elevated pollution levels.
• Dust: The same 2018 research paper attributed 21.5% of air pollution to dust.
• Industrial emissions: The Ministry of Earth Sciences' research paper also attributed 18% of air pollution to industrial emissions.
• Thermal power plants: The National Capital Region's thermal power plants contribute to Delhi's air pollution.
• Stubble burning: Farmers in neighbouring states burn crop stubble to clear fields, releasing massive amounts of smoke and harmful particles into the air, which are then carried into Delhi by winds.
• Road dust: A 2016 study found that 38% of PM2.5 pollution and 56% of PM10 pollution in Delhi came from road dust.
• Fireworks during festivals: Despite being banned, firecrackers continue to be burst during festivals like Diwali, releasing harmful chemicals and adding to the pollution.
• Construction: Delhi's rapid urban growth and construction create a lot of dust and pollution.
• Wood-burning fires, cow dung cake combustion, and exhaust from diesel generators: These activities contribute to the poor air quality in Delhi.

The socioeconomic disparities in exposure to air pollution

Delhi, the capital territory of India, has been found to have the worst air quality of any major city in the world. The air pollution in Delhi affects the surrounding districts and is estimated to kill about 2 million people every year. The air quality in Delhi is affected by several factors, including vehicular emissions, industrial emissions, dust, agricultural stubble burning, and thermal power plants. The poor air quality in Delhi has severe health effects on its residents, causing respiratory problems, lung damage, and increasing the risk of cancer and other diseases.

Socioeconomic disparities in exposure to air pollution exist in Delhi, with lower socioeconomic status (SES) individuals and communities experiencing higher levels of air pollution. Studies have shown that areas with low SES in Delhi have higher concentrations of particulate matter (PM), nitrogen dioxide (NO2), and other air pollutants. This is due to various factors such as the location of pollution sources near disadvantaged communities and limited access to resources that can reduce exposure, such as private transportation. Additionally, low SES communities may have higher susceptibility to health threats due to psychosocial stressors, chronic stress, and limited opportunities for health-promoting behaviors. Addressing these disparities and reducing air pollution exposure for vulnerable populations is crucial for improving public health and reducing health inequalities in Delhi.

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