Air Pollution In Big Cities: Major Causes Revealed

Air pollution is a critical issue that poses a significant threat to human health and the planet. It is one of the leading causes of environmental health problems globally, with nearly seven million deaths attributed to it annually. Urban areas, particularly large cities, are often hotspots for poor air quality, and understanding the causes of air pollution in these areas is crucial for designing effective solutions. While cars and transport are commonly perceived as the primary sources of air pollution, other factors play a significant role as well. This paragraph aims to delve into the various causes of air pollution in big cities and their impact on the environment and human health.

Vehicle emissions

The impact of vehicle emissions on air quality is complex and influenced by various factors. The dispersion and dilution of pollutants depend on environmental conditions such as weather patterns. However, the high population density in cities intensifies the effects of vehicle emissions, as a larger number of people are exposed to the pollutants. This is especially true in cities with dense traffic and inadequate urban planning, where residents are more susceptible to the harmful effects of vehicle emissions.

Furthermore, the interaction between vehicle emissions and other sources of air pollution, such as industrial emissions and power generation, can exacerbate the problem. The concentration of multiple pollutants in the air increases the overall toxicity and poses greater risks to human health and the environment. This is particularly concerning in cities located in developing regions, where income levels are lower and access to healthcare may be limited.

To address the issue of vehicle emissions and improve air quality in big cities, several interventions can be implemented. These include promoting sustainable transport options, such as public transportation, walking, and cycling, as well as encouraging the adoption of electric or hybrid vehicles. Additionally, implementing stricter emission standards and regulations for vehicles can help reduce the release of harmful pollutants.

Industrial emissions

The burning of fossil fuels, such as coal, gasoline, and natural gas, is a major source of industrial emissions. This includes coal-burning power plants, which are known to produce high levels of sulfur dioxide and nitrogen oxides. These emissions can cause respiratory issues, irritate the eyes and throat, and have negative impacts on the lungs, especially for children and the elderly. Additionally, nitrogen oxides can worsen asthma symptoms and even contribute to the development of asthma in children.

Thermal power plants that burn coal with high sulfur content are a significant source of sulfur dioxide emissions. When sulfur oxides react with rainwater, they form sulfuric acid, commonly known as acid rain. This phenomenon has far-reaching ecological consequences, affecting water bodies, soil, and vegetation.

In addition to power generation, manufacturing industries also contribute to air pollution. The Clean Air Act in the United States has been successful in reducing harmful emissions from transportation, power plants, and manufacturing. However, climate change-fueled wildfires and extreme heat pose new challenges to maintaining healthy air quality.

Furthermore, urban population growth, coupled with changing land use patterns, exacerbates the problem of industrial emissions. As cities expand and experience population increases, the emission rate of air pollutants rises. This trend is particularly noticeable in developing countries, where industrialization and urbanization are occurring at a rapid pace.

Commercial cooking

The degree of risk posed by commercial cooking to air quality is related to the intensity of the activity, the cooking style, and the presence or absence of mitigation strategies such as ventilation or filtration.

Sources of Air Pollution in Commercial Cooking

Commercial kitchens use a variety of heat sources, such as gas, wood, and electricity, to cook food. Each of these sources can generate indoor air pollution. Gas stoves, for instance, can release harmful pollutants like carbon monoxide and formaldehyde, while wood-fired stoves produce high levels of indoor air pollution from wood smoke.

The type of cooking also influences the level of pollution. Frying and deep-frying, for example, release high amounts of PM and other harmful pollutants due to the high temperatures involved. The cooking oils and food being cooked can also be sources of air pollution, especially when burned or charred.

Mitigation Strategies

To reduce the impact of commercial cooking on air pollution, several strategies can be employed:

• Ventilation: Proper ventilation is crucial. Range hoods, extractor fans, and open windows can help remove airborne pollutants.
• Clean Surfaces: Regular cleaning of cooking surfaces can prevent the buildup of burnt-on food and sauces, reducing indoor air pollution.
• Cover Pots and Pans: This simple act can help contain pollutants and also reduce energy consumption.
• Choose Cooking Oils Wisely: Opt for oils with high smoke points suitable for the cooking style to avoid burning.
• Enhanced Ventilation and Filtration: Consult experts to ensure sufficient ventilation and incorporate filtration and air purification systems.

Wood burning

Residential wood burning is a notable source of fine particle pollution (PM2.5) in many regions. For instance, in the United Kingdom, wood burning contributes more to fine particle pollution than traffic emissions. Similarly, in California, wood-burning stoves and fireplaces produce more PM2.5 than all motor vehicle exhaust emissions combined. Wood smoke is also more ecotoxic than particulates emitted from modern diesel engines.

The health effects of wood-burning emissions include coughing, wheezing, asthma attacks, heart attacks, and premature death. Additionally, wood smoke can irritate the lungs, cause inflammation, affect the immune system, and increase susceptibility to lung infections, including potentially SARS-CoV-2, the virus that causes COVID-19. To mitigate the impact of wood-burning emissions, it is recommended to avoid burning wood, especially during high pollution days, and explore alternative heating sources such as solar panels or electric heat pumps.

Construction

In the UK, for example, construction and traffic related to it are a much larger source of particulate matter air pollution than how people travel and get around the city. Data from the London boroughs of Lambeth and Southwark revealed that nearly 70% of particulate matter is related to the built environment, such as the heating of buildings, construction, and associated traffic.

The impact of construction on air quality is particularly notable in rapidly urbanizing areas. As cities expand and the demand for new buildings and infrastructure increases, construction activities can intensify, leading to higher emissions of air pollutants. This trend is observed in both industrialized and developing nations, with the emission rate per inhabitant expected to rise in the latter due to rapid urbanization and industrialization.

Furthermore, construction projects can disrupt the natural environment, leading to increased dust and particulate matter in the air. They can also contribute to the combustion of fossil fuels, which is a significant source of air pollution. Construction vehicles, machinery, and equipment often rely on fossil fuels, releasing pollutants such as nitrogen oxides and sulfur dioxide into the atmosphere.

To mitigate the impact of construction on air pollution, sustainable practices, and regulations are essential. This includes adopting cleaner technologies, improving energy efficiency, and implementing effective waste management practices. By addressing the emissions and practices associated with construction, cities can work towards improving air quality and reducing the health risks associated with polluted air.

Frequently asked questions