Indoor Air Pollution: A Silent Killer In Homes

Air pollution is a serious issue that affects people worldwide, causing millions of premature deaths each year. While the exact number of fatalities is uncertain, estimates range from 6.7 million to 8.9 million deaths per year. Indoor air pollution, caused by the use of polluting fuels for cooking and heating, is a significant contributor to this figure. In 2021, it was reported that 500,000 deaths of children under five were linked to household air pollution, mainly in Africa and Asia. The World Health Organization (WHO) estimates that 3.8 million deaths are caused by indoor air pollution from burning wood and charcoal. This issue is particularly prevalent in low- and middle-income countries, where populations suffer the highest exposures to indoor air pollution.

Burning wood and charcoal

Wood-burning releases harmful emissions, including particle pollution, carbon monoxide, nitrogen oxides, and volatile organic compounds. These pollutants can have both immediate and long-term effects on human health. For instance, emissions from wood smoke can cause coughing, wheezing, asthma attacks, and even heart attacks. People with pre-existing health conditions, such as lung disease, cardiovascular disease, and diabetes, are at an even higher risk of experiencing adverse effects.

Charcoal burning also produces toxic chemicals and smoke, which can fill homes that often have poor ventilation. This combination of charcoal burning and inadequate ventilation results in extremely high levels of indoor air pollution. Women and children, especially in extreme poverty, are often the most vulnerable to the detrimental effects of indoor air pollution caused by burning charcoal and wood.

The impact of burning wood and charcoal goes beyond individual households. Wood-burning, particularly in closed stoves and open fires, has been identified as a major contributor to particle pollution in the United Kingdom, with a significant increase in PM2.5 emissions since 2003. This type of tiny particle pollution is harmful as it can enter the bloodstream and travel throughout the body, potentially affecting various organs.

While the exact number of deaths specifically attributed to burning wood and charcoal is challenging to pinpoint, indoor air pollution as a whole has been deemed the deadliest environmental problem. According to various studies, indoor air pollution claims the lives of between 3.5 to 4.3 million people annually, with the World Health Organization estimating an even higher death toll of 3.8 million. These numbers far surpass the annual death count from other critical issues such as HIV/AIDS and homicides.

To address the health risks associated with burning wood and charcoal, it is essential to explore cleaner alternatives and technologies. Access to clean energy sources, such as solar panels, electric heat pumps, and improved cookstoves with better ventilation, can significantly reduce indoor air pollution and its detrimental impact on human health.

Fossil fuel combustion

The health impacts of indoor air pollution from fossil fuel combustion are significant. Particulate matter and other pollutants released during combustion can infiltrate deep into the lungs and even enter the bloodstream. These pollutants irritate the airways and lungs, impair the immune system, and reduce the blood's ability to carry oxygen. Women and children are particularly vulnerable to the effects of indoor air pollution as they tend to spend more time near the domestic hearth, where smoke concentrations can reach levels 100 times higher than acceptable. Furthermore, children under five and developing fetuses are at an increased risk of adverse health effects due to their developing respiratory and immune systems.

The consequences of indoor air pollution from fossil fuel combustion extend beyond immediate health impacts. The inefficient combustion of fuels in poorly ventilated dwellings contributes to ambient (outdoor) air pollution, affecting the broader community. Additionally, the reliance on polluting fuels often requires significant time for cooking and fuel gathering, impacting the productivity and well-being of individuals, especially in low-income households.

Addressing indoor air pollution from fossil fuel combustion is crucial. WHO has issued guidelines for indoor air quality, providing recommendations on clean fuels and technologies, such as solar power, electricity, liquefied petroleum gas (LPG), natural gas, and improved biomass stoves. Implementing these guidelines can significantly reduce the health risks associated with indoor air pollution and improve the overall well-being of households.

According to various studies, the global impact of fossil fuel combustion on indoor and outdoor air pollution is substantial. Research by Vohra et al. (2021) estimated that 8.7 million deaths worldwide in 2018 were attributable to outdoor air pollution caused by fossil fuel combustion. Another study by Lelieveld et al. (2019) found that 3.6 million premature deaths annually could be attributed to burning fossil fuels for power generation, transportation, and industry. These figures highlight the urgent need to transition to clean and renewable energy sources to mitigate the devastating health impacts of fossil fuel combustion.

Cooking with polluting fuels

HAP generated from the use of polluting cooking fuels and technologies is a significant source of disease and environmental degradation. The inefficient combustion of solid fuels, such as wood, coal, charcoal, dung, crop waste, and kerosene, in simple stoves and devices, produces high levels of HAP. Chronic exposure to HAP increases the risk of non-communicable diseases, including ischemic heart disease, stroke, chronic obstructive pulmonary disease, lung cancer, and pneumonia. Women and children are particularly vulnerable to the health risks associated with HAP, as they tend to spend more time around the stove.

The number of people relying primarily on polluting fuels for cooking has declined globally. In 1990, over half of the global population used polluting fuels for cooking, dropping to about 26% in 2022. However, current estimates suggest that one-third of the global population will continue to use polluting fuels by 2030, with the majority residing in Sub-Saharan Africa. The reliance on polluting fuels is particularly prevalent in rural populations, where biomass fuels, such as wood and animal dung, are commonly used.

Access to clean cooking fuels and technologies is crucial for improving health outcomes and reducing environmental degradation. The transition to clean cooking fuels and technologies can help reduce the health risks associated with HAP and improve the overall quality of life for millions of people worldwide. However, progress towards achieving universal access to clean cooking has been slow, and the COVID-19 pandemic has further slowed down these efforts.

To address the issue of household air pollution, the WHO's Air Quality and Health Unit provides normative guidance, tools, and advice to countries. Additionally, the unit monitors and reports on global trends and changes in the health impacts of air pollution. These efforts are crucial in working towards the goal of universal access to clean and sustainable energy, as outlined in the United Nations' Sustainable Development Goals.

Poor air quality in low-income countries

Poor air quality is a pressing issue in low-income countries, contributing significantly to health issues and socioeconomic challenges. Firstly, it is important to understand the factors that lead to poor air quality in these regions. Low-income countries often have less stringent air quality regulations and rely more heavily on polluting industries, technologies, and practices. This includes the use of older, more polluting machinery and vehicles, as well as fossil fuel subsidies, congested transport systems, and cut-and-burn practices in agriculture. As a result, air pollution levels tend to be significantly higher in low-income countries, posing a considerable risk to the health and well-being of their populations.

One of the key factors contributing to poor air quality in low-income countries is the concentration of major pollutant emitters, such as power plants, factories, and highways, in low-income neighbourhoods. Decision-makers often choose these locations as they anticipate less opposition from these communities. Additionally, low-income neighbourhoods may offer financial incentives for industries, such as cheaper land, low-cost labour, and convenient transportation options. This results in higher air pollution levels in these areas, impacting the health and quality of life of residents.

The health consequences of poor air quality in low-income countries are significant. Air pollution has been linked to respiratory diseases, heart disease, adverse birth outcomes, and an increased risk of asthma and lung diseases. Low-income individuals are particularly vulnerable as they are more likely to work in outdoor physical labour jobs, exposing them to higher levels of pollution. Furthermore, limited access to affordable and adequate healthcare in low-income countries exacerbates the impact of pollution-related diseases, leading to higher mortality rates.

The socioeconomic implications of poor air quality in low-income countries are also noteworthy. The high levels of air pollution can drive down housing prices in affected areas, reinforcing their status as low-income neighbourhoods. Additionally, the health impacts of air pollution can affect the socio-economic prospects of these countries, impacting their economic development and the well-being of their populations. It is crucial to address the disproportionate exposure of low-income communities to air pollution through targeted measures, improved healthcare provisions, and the removal of incentives that encourage the over-consumption of polluting fuels.

Household combustion devices

Air pollution is a leading cause of death, with an estimated 7 million deaths per year, according to the World Health Organization (WHO). Of these, 3.8 million are attributed to indoor air pollution from burning wood and charcoal. The Institute for Health Metrics and Evaluation (IHME) provides a similar estimate of 6.7 million deaths. These deaths are caused by various sources, including household combustion devices.

The impact of household combustion devices on indoor air quality is particularly concerning in developing countries, where nearly 3 billion people rely on solid fuels for cooking and household energy needs. The use of inefficient and poorly vented combustion devices, such as open fires and traditional stoves, exacerbates the problem by releasing pollutants directly into the living environment. This exposure is higher among women and children, who spend more time near the domestic hearth and are involved in cooking and fuel preparation.

To address the issue of household air pollution, the WHO has developed guidelines for indoor air quality and household fuel combustion. These guidelines provide recommendations on the types of fuels and technologies that can reduce health risks and environmental impacts. They emphasize the importance of transitioning to cleaner fuels and technologies, such as improved combustion stoves, that can efficiently burn fuels with lower emissions. Additionally, the guidelines highlight the need to address all household energy uses, including cooking, space heating, and lighting, to ensure significant health and environmental benefits.

The dissemination and adoption of cleaner household fuels and technologies are crucial in mitigating the health risks associated with household combustion devices. This includes promoting access to modern fuels and improving the design and efficiency of combustion appliances. By transitioning to cleaner alternatives, such as improved combustion stoves and cleaner sources of energy, the global health burden of household air pollution can be significantly reduced.

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