Outdoor Air Pollution: Understanding The Main Causes

Outdoor air pollution is a pressing environmental and health issue, causing an estimated 4.2 million premature deaths worldwide in 2019. It is caused by the release of harmful substances into the Earth's atmosphere, which can compromise human health, damage the environment, and even cause death. Outdoor air pollution is mainly caused by energy use and production, with the burning of fossil fuels being a significant contributor. This includes gasoline for cars, oil for heating homes, and fracked gas for power plants. Other sources of outdoor air pollution include wildfires, bonfires, and industrial activities such as smelting and mining.

Fossil fuels and transport

Outdoor air pollution is a pressing environmental and health issue, causing an estimated 4.2 million premature deaths worldwide in 2019. Fossil fuels and transport are significant contributors to this problem, with transport activities accounting for a substantial proportion of air pollution. The burning of fossil fuels, particularly coal, petrol, and diesel, releases harmful pollutants into the atmosphere, adversely affecting air quality and human health.

Fossil fuels, when burned, emit toxic gases and particulate matter, which have detrimental effects on the environment and human health. One of the primary gases released during fossil fuel combustion is nitrogen oxide, which contributes to the formation of smog and acid rain. Nitrogen oxide emissions from transport activities, such as driving cars and trucks, are particularly concerning. To mitigate this issue, individuals can consolidate driving trips, opt for carpooling, or use public transportation, or choose active modes of travel like walking or biking.

Additionally, fossil fuel combustion releases carbon monoxide, a colourless, odourless, and toxic gas. Carbon monoxide is produced through the incomplete burning of carbon-containing fuels, including petrol, charcoal, and natural gas. This gas is hazardous to human health and contributes to the overall degradation of air quality. Furthermore, the burning of fossil fuels is a major source of fine particulate matter (PM2.5), which has been linked to increased mortality and various health issues.

The transportation sector relies heavily on fossil fuels, particularly for road and air travel. Vehicles, including cars and trucks, and planes, burn fossil fuels like petrol and diesel, releasing pollutants into the atmosphere. This contributes significantly to the overall air pollution levels and has adverse effects on human health and the environment. To address this issue, there is a growing emphasis on transitioning to cleaner, renewable energy sources, such as electric power generation and alternative fuels for transportation.

Addressing air pollution from fossil fuels and transport is crucial to protect public health and the environment. By transitioning to cleaner energy sources, improving energy efficiency, and adopting sustainable practices, we can mitigate the harmful impacts of air pollution. This includes encouraging the use of renewable energy sources, such as solar, wind, and hydroelectric power, which can significantly reduce the environmental and health impacts associated with fossil fuel combustion and transport emissions.

Industrial activities

Industrial facilities, including power plants, oil refineries, and factories, are stationary sources of pollution that emit large quantities of harmful substances into the atmosphere. These emissions contain various pollutants, such as particulate matter (PM), carbon monoxide (CO), nitrogen dioxide (NO2), and ozone (O3).

Particulate matter, a mixture of solid and liquid particles suspended in the air, is a significant contributor to air pollution. It includes substances like sulfates, nitrates, ammonia, black carbon, and mineral dust, which have detrimental health effects when inhaled. Carbon monoxide, an invisible, odourless, and toxic gas produced by the incomplete combustion of fuels, poses serious health risks by reducing the blood's ability to transport oxygen. Nitrogen dioxide, another harmful gas released during fuel combustion in industrial processes, can irritate the respiratory system and worsen conditions like asthma.

Additionally, industrial activities contribute to elevated ozone concentrations in the lower atmosphere. Ozone, while beneficial in the upper atmosphere (stratosphere) as it protects us from UV radiation, is a harmful component of smog at ground level. It is formed through the reaction of certain gases in the presence of sunlight. The release of these gases from industrial processes, such as oil and gas development, leads to increased ozone levels, which can have detrimental effects on human health and the environment.

To address industrial air pollution, various interventions have been proposed. These include implementing clean technologies to reduce emissions from industrial smokestacks, adopting improved waste management practices, and transitioning to cleaner sources of energy. By prioritizing sustainable practices and reducing harmful emissions, we can effectively mitigate the impact of industrial activities on outdoor air pollution.

Wildfires

Outdoor air pollution is a pressing environmental and health issue, causing an estimated 4.2 million premature deaths worldwide in 2019. One significant contributor to this problem is wildfires, which produce a range of harmful air pollutants, from cancer-causing substances to tiny particles that can have detrimental effects on human health.

Wildfire smoke contains particulate matter (PM), which is considered the main pollutant of concern. Fine particles, known as PM2.5, with diameters of 2.5 micrometres or smaller, make up around 90% of the total particle mass in wildfire smoke. These particles can easily penetrate homes and buildings, increasing indoor particle concentrations. Due to their minuscule size, they can infiltrate the deep recesses of the lungs and may even enter the bloodstream. The association between PM2.5 and adverse heart and lung health effects is well-documented in scientific literature. Ultrafine particles, with diameters less than 0.1 micrometres, are also present in wildfire smoke, posing additional health risks.

The health consequences of exposure to wildfire smoke are particularly concerning for individuals with pre-existing cardiovascular or respiratory diseases, older adults, children under 18, pregnant women, outdoor workers, and those of lower socioeconomic status. These vulnerable groups are at an increased risk of experiencing health issues due to the fine particulate matter in wildfire smoke.

To mitigate the health impacts of wildfire smoke, it is recommended to stay indoors with windows and doors closed. Using air conditioning with the recirculate setting turned on can also help reduce exposure to smoke particles. In areas with central-ducted air conditioning, setting the system to "on" ensures constant air filtration. Additionally, installing high-efficiency filters and using air cleaners can significantly reduce indoor particle levels.

Poor waste management

One of the main issues with poor waste management is the unsafe disposal of waste. This includes practices such as open dumping, uncontrolled dumping, and burning waste in open spaces or uncontrolled incinerators. When waste is disposed of in this manner, it releases harmful substances, chemicals, and fine particles into the air, leading to air pollution. These particles and pollutants can cause respiratory diseases, nose and throat infections, and exacerbate cardiovascular illnesses, such as ischaemic heart disease, and lung cancer. Additionally, the open burning of waste increases the risk of infections, inflammation, inhalation difficulties, bacterial infections, and asthma.

The mixing of household and commercial garbage with hazardous waste during storage and handling further exacerbates the problem. Waste is often stored in old or poorly managed facilities, and the transportation system is frequently deficient and informal. These practices result in air pollution, as well as water pollution, land degradation, and emissions of methane and hazardous leachate. Furthermore, the disposal of non-biodegradable waste, such as plastics, bottles, and tins, can create breeding grounds for mosquitoes, increasing the risk of diseases like malaria and dengue.

The impact of poor waste management disproportionately affects people in low- and middle-income countries, where 89% of outdoor air pollution-related premature deaths occur. These countries often lack proper waste management infrastructure and safe handling techniques. The United Nations Environment Programme (UNEP), through its International Environmental Technology Centre (IETC), is working with governments in Asia, Africa, and Latin America to improve waste management practices and prevent air pollution. Their initiatives include developing better waste management plans, improving waste-handling techniques, and promoting the circularity of waste as a resource.

To address the issue of poor waste management and its impact on outdoor air pollution, it is essential to prioritize waste reduction and implement safer, more environmentally friendly disposal methods. Recycling, remanufacturing, and recovering materials and energy from waste can play a crucial role in minimizing the negative impacts on human health and the environment. Additionally, public awareness campaigns can help educate individuals about the importance of proper waste disposal practices and their role in reducing air pollution.

Incomplete combustion

Outdoor air pollution is a pressing environmental and health issue, causing an estimated 4.2 million premature deaths worldwide in 2019. One of the key contributors to this problem is incomplete combustion, which releases harmful pollutants into the atmosphere.

The health effects of carbon monoxide exposure are well-documented. At elevated levels, carbon monoxide can cause headaches, fatigue, and nausea. Even more alarming, extremely high levels of carbon monoxide can lead to brain and heart damage and, in severe cases, death. Additionally, carbon monoxide plays a role in atmospheric chemical reactions that produce ozone, a climate change gas. While the direct effect of carbon monoxide on climate change is considered weak, its indirect contribution through ozone formation is significant.

To address the issue of carbon monoxide emissions from incomplete combustion, various strategies can be implemented. These include improving fuel efficiency in combustion sources, such as vehicles and power plants, and implementing regulations and standards for carbon monoxide emissions. Additionally, promoting the use of cleaner and more sustainable energy sources, such as renewable energy, can help reduce the occurrence of incomplete combustion and the resulting carbon monoxide emissions.

Furthermore, public awareness and education about the dangers of carbon monoxide are crucial. Installing carbon monoxide detectors or alarms in dwellings with fuel-type appliances or attached garages, as mandated by laws like California's Carbon Monoxide Poisoning Prevention Act of 2010, is essential for early detection and prevention of carbon monoxide poisoning. By combining emissions reduction strategies with public awareness and safety measures, we can effectively mitigate the impact of incomplete combustion on outdoor air pollution and protect the health and safety of communities.

Frequently asked questions