Human Activities: The Main Cause Of Air Pollution

Air pollution is a pressing issue that poses severe health risks to people worldwide, particularly those in low- and middle-income countries. It is caused by a range of human activities and natural sources, including vehicle emissions, fuel oils, natural gas combustion, manufacturing by-products, power generation, and natural occurrences like wildfires and volcanic eruptions. These sources release harmful gases and particles, such as nitrogen oxide, sulphur dioxide, and particulate matter, into the atmosphere, leading to respiratory and cardiovascular diseases, cancers, and other health issues. The impact of air pollution extends beyond human health, affecting ecosystems, soil quality, and water sources. Addressing air pollution requires concerted efforts and policy interventions to mitigate its detrimental effects on the environment and human well-being.

Vehicle emissions

One of the most well-known consequences of vehicle emissions is the formation of smog, a type of air pollution that is common in cities and can reduce visibility. Smog is created when pollutants from vehicle exhausts, such as nitrogen oxides, react with ozone in the presence of sunlight. This reaction results in a smoky fog that hangs over cities, degrading air quality and making it difficult to see.

The health impacts of vehicle emissions are significant. Exposure to air pollution, especially at a young age, can lead to an increased risk of developing respiratory conditions, such as bronchitis and asthma, and can stunt lung development. Studies have also linked air pollution to an elevated risk of lung cancer, colorectal cancer, prostate cancer, and cerebral palsy. Additionally, fine particulate matter from vehicle emissions can impair blood vessel function and accelerate the calcification of arteries.

Recognizing the harmful effects of vehicle emissions, organizations like the US Environmental Protection Agency (EPA) and the California Air Resources Board (CARB) have implemented standards and regulations to reduce emissions from transportation sources. These efforts have resulted in significant improvements in air quality, particularly in US cities. The EPA has set stringent emissions standards for passenger vehicles, heavy-duty vehicles, and various types of equipment, while also promoting investments in clean vehicle and engine technology. Similarly, CARB has conducted research to support policies and programs aimed at reducing emissions from on-road and off-road vehicles in California.

Fossil fuels

The combustion of these fuels produces fine particulate matter, known as PM2.5, which includes particles such as soot. These particles are extremely small, with a diameter of up to 2.5 microns, making them easily inhalable and capable of penetrating deep into the lungs. From there, they can enter the bloodstream and cause damage to multiple organs. Exposure to PM2.5 has been linked to an increased risk of various health issues, including lung cancer, colorectal and prostate cancers, cerebral palsy, and developmental problems in children.

The health impacts of fossil fuel air pollution are significant, with recent studies highlighting its deadly consequences. According to research, fossil fuel air pollution is responsible for approximately 8.7 million deaths globally each year, with some estimates even reaching 10.2 million. This makes it a leading cause of mortality, outpacing other health issues such as HIV, tuberculosis, and malaria combined. The burden of these deaths falls disproportionately on vulnerable populations, including children, older individuals, low-income communities, and people of color, particularly those residing in urban areas.

Additionally, the burning of fossil fuels contributes to ground-level ozone creation. While ozone in the upper atmosphere is beneficial as it blocks harmful radiation from the sun, ground-level ozone is a major air pollutant. It is formed when sunlight reacts with certain chemicals emitted from burning fossil fuels, such as those released by factories and car exhaust. Ground-level ozone creates smog, a visible form of air pollution that reduces visibility and further exacerbates respiratory issues.

Addressing fossil fuel air pollution is crucial, and transitioning to cleaner, renewable energy sources is imperative. By phasing out fossil fuels, we can significantly reduce air pollution emissions, improve air quality, and positively impact the health and well-being of millions of people worldwide.

Industrial processes

Industrial air pollution is caused by a range of processes and facilities, including fracking-related infrastructure, steel-making plants, petrochemical plants, and hazardous waste sites. The natural gas, plastic, chemical, electric generation, and waste disposal industries can generate hazardous waste that, if not properly disposed of, can create significant air pollution.

The extraction and processing of fossil fuels, in particular, have a significant impact on air quality. Every stage of oil and gas operations, from production and extraction to processing and distribution, releases pollutants that negatively affect public health and contribute to climate change. The burning of fossil fuels is a major source of ground-level ozone, a harmful pollutant that contributes to smog formation and has adverse effects on respiratory health.

In addition to ozone, industrial processes emit large quantities of organic compounds, carbon monoxide, and hydrocarbons into the atmosphere. These emissions can include toxic pollutants such as benzene, a known carcinogen associated with leukemia and non-Hodgkin's Lymphoma. Fine particulate matter, such as PM2.5, can have severe health impacts, including increased risks of respiratory issues, cognitive and emotional problems, and cardiovascular diseases.

To mitigate industrial air pollution, several measures can be implemented, including industrial processes upgradation, energy efficiency improvements, agricultural waste burning control, and fuel conversion. The development and utilization of technologies like CO2 sequestering, industrial energy efficiency enhancements, and vehicular engine combustion process improvements can also help reduce air pollution levels.

Agriculture

Cattle, pig, and chicken operations release methane, nitrous oxide, and ammonia into the air. These gases can impact the environment and pose dangers to human health. For example, high amounts of ozone in the atmosphere can inhibit plant growth. According to the United Nations Environment Programme (UNEP), ground-level ozone pollution created by fuel burning and chemical use will reduce staple crop yields by 26% by 2030.

Ammonia emissions from livestock manure and chemicals comprise 95% of ammonia emissions, which in turn account for 58% of the particulate matter air pollution in European cities. In addition, chemical drift with pesticides, herbicides, and fertilizers can occur as these compounds reach nearby lands or neighbourhoods and contribute to poor air quality elsewhere.

Fertilizer production has skyrocketed from about 20 million tons in 1950 to nearly 190 million tons today, with about a third of them being nitrogen-based. As a result, vast quantities of excess fertilizers wash off fields each year, polluting huge watersheds. However, industrial sulfates in fertilizers have been credited with reflecting solar radiation and thus slightly mitigating ongoing global warming caused by other fossil fuel emissions.

Agricultural pollution is a prime source of fine-particulate precursors. More than half the aerosol ingredients in much of the eastern and central United States come from farming, and the effect is even stronger in Europe and China. These aerosols form mainly downwind of farming areas in densely populated places where farm emissions combine with those of cars, trucks, and other sources.

Natural sources

Another natural source of air pollution is organic compounds from plants, which can include pollen and mould spores. These organic compounds can be released into the air and contribute to air pollution levels. Additionally, methane is a natural greenhouse gas emitted from decomposing organic matter in soils and from livestock such as cows and sheep. Methane is the second most important greenhouse gas, which can cause climate change.

Ozone is also a natural source of air pollution and can be both good and bad for the environment. While ozone high up in the atmosphere helps block harmful energy from the sun, ground-level ozone is created when sunlight reacts with certain chemicals from burning fossil fuels. This ground-level ozone is often referred to as smog and can be harmful to human health.

Furthermore, wind can transport and disperse air pollutants over short or long distances, leading to harmful impacts on downwind areas. This means that even remote natural sources of pollution can have significant effects on air quality in other regions. Overall, while natural sources of air pollution exist, human activities, such as burning fossil fuels, vehicle exhaust fumes, and industrial emissions, are the major contributors to air pollution globally.

Frequently asked questions