The Culprits Behind Pollution: Uncovering The Main Causes

Air pollution is a major threat to global health and prosperity, causing more than 6.5 million deaths each year. It is caused by solid and liquid particles and certain gases that are suspended in the air. These particles and gases can come from car and truck exhaust, factories, dust, pollen, mould spores, volcanoes, and wildfires. The solid and liquid particles suspended in the air are called aerosols. Many aerosols enter the atmosphere when we burn fossil fuels such as coal and petroleum, and wood. These particles can come from many sources, including car exhaust, factories, and even wildfires. Some of the particles and gases come directly from these sources, but others form through chemical reactions in the air.

Vehicle emissions

Vehicles release various pollutants into the air, including carbon monoxide (CO), nitrogen dioxide (NO2), particulate matter (PM), and volatile organic compounds (VOCs). These emissions have detrimental effects on both the climate and human health. In 2011, an Environmental Protection Agency (EPA) study revealed that California's lakes, bays, wetlands, and estuaries failed to meet water quality standards, impacting aquatic ecosystems and further contributing to air pollution.

Nitrogen oxides (NOx), a key ingredient in smog formation, are of particular concern. While nitrogen is naturally present in soil, its leakage into the air creates nitrogen oxide, which is a major health hazard, especially for children and the elderly. The Los Angeles-Long Beach-Riverside area ranked first in ozone pollution and fourth in annual and 24-hour particle pollution in 2013. High levels of nitrogen oxides and particulate matter can cause respiratory and cardiovascular issues, increased risk of cancer, and even contribute to premature deaths.

To combat this issue, California has implemented strict vehicle emissions laws, and the results have been significant. Between 1998 and 2018, the number of potential cancers linked to toxic air pollutants declined by 87% in LA. Additionally, organic aerosol levels have been halved in the Los Angeles basin between 1999 and 2012. These improvements are a direct result of the state's efforts to reduce vehicle emissions, showcasing the effectiveness of regulatory measures in improving air quality.

While the COVID-19 pandemic brought a temporary improvement in air quality due to reduced transportation and lockdowns, the long-term solution lies in addressing the root causes of pollution. This includes transitioning from a linear economy, fueled by cheap and disposable goods, to a circular economy that prioritizes restorative and regenerative practices in industrial and natural resource-based production systems. By tackling the complex drivers of air pollution and promoting clean energy and energy efficiency, cities like Los Angeles can improve air quality and mitigate the health risks associated with vehicle emissions.

Industrial processes

The rapid increase in industrialization has led to a significant rise in the volume of wastewater discharged into water bodies. Industrial wastewaters contain a range of pollutants, including mud and gravel, mess from canteens, concrete, masonry, scrap metal, trash, oil, solvents, chemicals, and organic matter. These pollutants degrade water quality and disrupt marine ecosystems, posing a serious risk to human health and the environment.

In addition to water pollution, industrial processes also contribute to air pollution. Emissions from power plants, refineries, and manufacturing facilities release harmful substances into the atmosphere. For example, nitrogen oxide, a key ingredient in smog, is produced by coal-fired power plants and certain industrial processes, leading to respiratory issues and other health problems. Fine particles, or particulate matter, released into the air from industrial activities can cause serious health issues, particularly for children, the elderly, and those with pre-existing respiratory conditions.

To address industrial pollution, various measures have been implemented. The European Union (EU), for instance, has strict regulations on industrial emissions, covering over 50,000 plants in EU countries. These regulations aim to control and reduce emissions of pollutants into the air and water, as well as greenhouse gas emissions. EU rules require large industrial plants to report and monitor their environmental performance and take action to control their emissions. Similar efforts are being supported by organizations like the World Bank, which is helping countries like China, Egypt, and Mexico improve air quality and address the complex drivers of air pollution.

The negative impacts of industrial pollution are far-reaching and have led to calls for better environmental stewardship. While there have been some successes in reducing emissions and improving air and water quality, industrial activities continue to be a major source of pollution, underscoring the need for ongoing efforts to mitigate their environmental and health impacts.

Natural sources

One of the main components of smog is nitrogen oxide, which is leaked into the air from the soil on agricultural land. This can cause a range of health issues, particularly in children and the elderly. In addition, organic compounds from plants, sea salt, suspended soils, and dust (such as from the Sahara) are natural sources of air pollution.

Livestock is the biggest source of methane, a colourless gas produced in an animal's stomach when bacteria break down food. It is the second most important greenhouse gas, which can cause climate change.

Volcanic eruptions can spew massive amounts of sulphur dioxide into the atmosphere, and they used to be the main source of this atmospheric gas. Summertime wildfires can also reduce visibility in national parks.

Poor waste disposal

Landfills, a common method of waste disposal, have significant environmental and health impacts. Open and unsanitary landfills contribute to drinking water contamination, transmitting infections and diseases. The dispersal of debris from landfills pollutes ecosystems, and the release of toxic chemicals, such as nitrogen oxides, leads to smog formation and respiratory problems.

Improper waste disposal also affects water quality, especially in developing nations. More than 80% of polluted water is used for irrigation in these countries, leading to food safety concerns. Additionally, plastics and other wastes clog drains and further contaminate water sources.

The breakdown of waste releases gases like methane, a potent greenhouse gas contributing to global climate change. Waste also emits pollutants that thicken the ozone layer, leading to adverse weather conditions, rising sea levels, and habitat destruction.

Furthermore, rapid urbanization and population growth have overwhelmed sewage treatment facilities, resulting in untreated sewage from municipal wastewater systems and septic tanks contaminating water ecosystems with nutrients, solids, petroleum, metals, and biodegradable organic carbon.

To address these issues, waste minimization is crucial. Where waste is unavoidable, recovery, recycling, and remanufacturing should be prioritized to reduce environmental impacts and promote resource conservation.

Wildfires

Particulate matter, specifically PM2.5 (fine particles with diameters of 2.5 micrometres or smaller), is the main pollutant emitted from wildfire smoke. These fine particles can make up approximately 90% of the total particle mass in wildfire smoke. Due to their minuscule size, they can be inhaled deeply into the lungs and may even enter the bloodstream. This poses serious health risks, particularly for individuals with pre-existing cardiovascular or respiratory diseases, older adults, children, pregnant women, outdoor workers, and those of lower socioeconomic status. The health effects of PM2.5 exposure include an increased risk of cardiovascular and respiratory diseases, lung damage, and potential cognitive and emotional problems in children.

Wildfire smoke also contains coarse particles (PM10-2.5), which are larger than PM2.5 but still small enough to be inhaled and cause respiratory issues. These coarse particles are typically generated from mechanical operations like construction and agriculture, but they are also present in wildfire smoke.

Additionally, wildfires emit various gases, including carbon dioxide, carbon monoxide, nitrogen oxides (NOx), and sulfur oxides (SOx). These gases contribute to the formation of ground-level ozone, a major pollutant in cities that can have detrimental effects on human health. Ground-level ozone, often referred to as smog, is created when these gases react with sunlight in the presence of other pollutants.

The impact of wildfire-related air pollution can be mitigated by taking precautionary measures. During periods of heavy smoke, staying indoors with windows and doors closed can help reduce exposure. Using air conditioning with the recirculate mode turned on can also prevent outdoor smoke from entering indoor spaces. In areas with high wildfire activity, it is recommended to follow evacuation orders and travel to areas with better air quality.

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