Human Activities: Major Contributors To Air Pollution

Air pollution is a pressing issue that poses significant risks to human health and the planet. According to the World Health Organization (WHO), approximately 9 million people die prematurely each year due to indoor and outdoor air pollution, with fine particles penetrating deep into the lungs and cardiovascular system, causing diseases such as stroke, heart disease, and lung cancer. While natural factors like volcanoes and solar activity can contribute to climate change, human activities are the primary drivers of global warming. Since the late nineteenth century, human-induced emissions have increased heat-trapping gases, leading to a 1.8°F (1.0°C) rise in global temperatures. The burning of fossil fuels, deforestation, and land use changes have significantly contributed to the rise in carbon dioxide levels. Addressing air pollution is crucial not only for human health but also for building fairer societies and strengthening economies.

Fossil fuels and vehicle emissions

Vehicle emissions, particularly from cars and vans, are a major source of air pollution. While the fuel consumption of new vehicles has declined due to improvements in engine, powertrain, and vehicle technology, this progress has been slowed by a trend toward larger and more powerful vehicles. Electrification has emerged as a dominant technology in reducing fuel consumption, but the adoption of electric vehicles has lagged, with electric vehicles accounting for only 14% of global sales in 2022 compared to 46% for less efficient SUVs. To align with net-zero emission scenarios, emissions from cars and vans must decrease significantly each year through 2030, with a focus on improving fuel economy and accelerating electrification.

Several countries have implemented policies to address vehicle emissions. The United States, for example, has the Environmental Protection Agency (EPA), which regulates emissions and has set standards for reducing GHG emissions in light-duty and medium-duty vehicles. China has introduced a car trade-in policy that subsidizes the replacement of used fossil fuel-powered vehicles with new energy-efficient or fuel-efficient vehicles. The United Kingdom has mandated that by 2035, all new cars and vans sold must be zero-emission vehicles. Australia has also enacted the New Vehicle Efficiency Standard Act to reduce emissions from new cars and vans.

Natural gas is being explored as an alternative fuel for vehicles, offering potential greenhouse gas (GHG) emissions benefits over conventional fuels. Argonne National Laboratory's GREET model estimates that heavy-duty natural gas vehicles can provide small to moderate GHG reductions compared to diesel. Renewable natural gas (RNG), or biomethane, yields significantly lower life cycle GHG emissions than conventional natural gas. Converting conventional vehicles to operate on natural gas can be a viable option for reducing emissions, and EPA regulations ensure that converted vehicles meet the same emissions standards as original vehicles.

Overall, addressing fossil fuel and vehicle emissions is crucial for mitigating air pollution and its detrimental effects on human health and the planet.

Industrial facilities

Additionally, industrial activities contribute to environmental degradation, causing acid rain and climate change. Acid rain is a result of sulfur dioxide and nitrogen oxide emissions from industrial facilities reacting with water vapour and oxygen in the atmosphere. Climate change is influenced by the release of greenhouse gases, such as carbon dioxide and methane, which are byproducts of fossil fuel combustion and industrial processes like oil and gas drilling. These gases trap heat in the Earth's atmosphere, leading to global warming, rising sea levels, more extreme weather events, and adverse health impacts.

The impact of industrial air pollution is disproportionately felt by communities of colour and low-income neighbourhoods, due to historical racist zoning policies and discriminatory practices that have sited polluting industries and highways near these areas. Environmental racism has resulted in residents of these communities suffering from the negative health consequences of breathing polluted air, as well as economic burdens from missed workdays and increased medical costs.

To mitigate the effects of industrial air pollution, the development and implementation of ambient air pollution control technologies are crucial. By investing in these technologies, industrial townships can improve the health and well-being of their residents and work towards a more sustainable future.

Forest and wildfires

Particulate matter, specifically PM2.5 (fine particles with a diameter of 2.5 micrometres or smaller), is a primary concern in wildfire smoke. These fine particles can travel long distances and have been detected in excessive levels hundreds of kilometres from the source of the fires. PM2.5 can aggravate asthma, trigger lung disease, induce heart attacks, and lead to premature deaths. The 2021 wildfires in North America and the 2023 wildfires in Siberia recorded exceptionally high levels of PM2.5, causing widespread health concerns.

The increase in wildfires is closely linked to climate change, creating a vicious cycle. Human activities, such as burning fossil fuels, transportation, and industrial processes, release greenhouse gases and black carbon emissions, contributing to climate change. As a result, the Earth's temperature rises, weather patterns become erratic, and drought conditions prolong, making forests more vulnerable to fires. Wildfires then release additional carbon emissions and greenhouse gases, further exacerbating climate change.

To break this cycle, it is crucial to address both climate change and air pollution. Reducing black carbon emissions is an effective strategy to prevent wildfires and improve public health. Additionally, community engagement in forest management and prescribed burning under controlled conditions can help mitigate the impacts of wildfires. As the frequency and intensity of wildfires continue to rise, interdisciplinary research and solutions are essential to tackle this urgent global challenge.

Furthermore, the economic and environmental costs of wildfires are significant. The 2023 wildfires in Chile caused an estimated $4.39 billion in damage, and the Canadian wildfires in the same year released more carbon in five months than Russia or Japan's annual fossil fuel emissions. The Australian wildfires of 2019-2020 produced carbon emissions 1.6 times greater than the country's total emissions for that period. These figures highlight the urgent need to address the interconnected issues of wildfires, climate change, and air pollution.

Household air pollution

The use of polluting fuels and technologies in households also poses safety risks. For example, kerosene, often sold in refilled soda bottles, is a leading cause of childhood poisonings. Open fires or unstable stoves can result in burns and scalds, especially among children. Additionally, fuel collection increases the risk of musculoskeletal damage from carrying heavy loads and the risk of injury or violence, especially in insecure areas.

To address household air pollution, the WHO has issued guidelines for indoor air quality, providing evidence-based guidance on clean fuels and technologies. These include solar, electricity, biogas, liquefied petroleum gas (LPG), natural gas, alcohol fuels, and biomass stoves that meet emission targets. While access to clean fuels and technologies is increasing, improvements are not keeping pace with population growth, particularly in low- and middle-income countries and regions like sub-Saharan Africa.

The impact of household air pollution is disproportionately felt by women and children, who are typically responsible for household chores such as cooking and collecting firewood. As a result, they bear the brunt of the health consequences associated with the use of polluting fuels and technologies. Urgent action is needed to address this issue and improve access to clean and sustainable alternatives to reduce the health burden of household air pollution.

In summary, household air pollution, caused by the use of inefficient and polluting fuels, poses a significant threat to human health, particularly in low- and middle-income countries. The WHO has recognized the issue and provided guidance to promote the adoption of cleaner alternatives. However, more needs to be done to ensure that everyone has access to clean cooking fuels and technologies to reduce the harmful health impacts of household air pollution.

Health effects of air pollution

Air pollution is a mix of hazardous substances from both human-made and natural sources. It is a major threat to global health and prosperity, causing more than 6.5 million deaths each year globally, a number that has increased over the past two decades. In 2019, air pollution caused about 6.7 million deaths, with almost 85% attributable to non-communicable diseases (NCDs) like ischemic heart disease, stroke, lung cancer, asthma, chronic obstructive pulmonary disease (COPD), and diabetes.

The health impacts of air pollution depend on the types, sources, and concentrations of the pollutants in the mixture to which an individual is exposed. Both short- and long-term exposure to air pollution can lead to a wide range of diseases, including stroke, chronic obstructive pulmonary disease, trachea, bronchus and lung cancers, aggravated asthma, and lower respiratory infections. The main pathway of exposure from air pollution is through the respiratory tract. Pollutants like dust, fumes, gas, mist, odour, smoke, or vapour can cause inflammation, oxidative stress, immunosuppression, and mutagenicity in cells throughout the body, impacting the lungs, heart, and brain, among other organs, and ultimately leading to disease.

Some air pollutants are greenhouse gases with significant climate impacts, further affecting the burden of morbidity and mortality caused by air pollution. Fine particulate matter (PM 2.5) poses the greatest health risks as these very small particles can penetrate deep into the lungs, enter the bloodstream, and travel to organs, causing systemic damage to tissues and cells. In Europe, air pollution is the single largest environmental health risk and a major cause of premature death and disease. The latest estimates by the European Environment Agency (EEA) show that fine particulate matter (PM 2.5) continues to cause the most substantial health impacts.

The World Health Organization (WHO) provides evidence of links between exposure to air pollution and type 2 diabetes, obesity, systemic inflammation, Alzheimer's disease, and dementia. The International Agency for Research on Cancer has classified air pollution, particularly PM2.5, as a leading cause of cancer. In 2021, the WHO published new air quality guidelines following a systematic review of the latest scientific evidence demonstrating how air pollution damages human health. The European Union (EU) has also set standards for key air pollutants in the Ambient Air Quality Directives.

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