Brazil's Air Pollution: Causes And Concerns

Brazil's air quality is generally good, with many of its cities falling within the World Health Organization's (WHO) target goal for good air quality. However, air pollution still kills about 49,000 Brazilians every year, with 25,000 of these deaths attributed to outdoor pollution and the remaining 24,000 caused by indoor air pollution. The main causes of outdoor air pollution in Brazil include vehicular emissions and fumes, ethanol production, and forest fires in the Amazon rainforest. On the other hand, indoor air pollution is primarily caused by cooking with wood and other solid fuels, affecting mostly rural communities.

Vehicular emissions and fumes

In São Paulo, the level of outdoor ambient air pollution was measured to be 22µg/m3, twice the World Health Organization's (WHO) limit of 10µg/m3. In six other major cities near busy streets, the range was 7-28µg/m3. Overall, about 40% of the Brazilian population is estimated to breathe air that is more polluted than the WHO guidelines.

The high levels of surface ozone (O3) in São Paulo are a serious concern. O3 and its precursors can worsen air quality in areas already affected by biofuels production, especially ethanol. O3 has been associated with harmful effects on human health, damage to crops, and climate change. In recent years, air pollutant emissions from thermal power plants have increased due to greater demand, with bagasse-fired power plants generating about 25% of the energy produced in the state of São Paulo.

In addition to vehicular emissions, forest fires in the Amazon release massive amounts of greenhouse gases and toxic pollutants into the atmosphere, with catastrophic consequences for the Brazilian economy and global climate change mitigation efforts. Forest fires produce a mixture of pollutants, including carbon monoxide, nitrogen dioxide, black carbon, brown carbon, and ozone precursors, among others. The principal public health threat is particulate matter smaller than 2.5 micrometers in diameter, known as PM2.5, which can penetrate deep into the lungs and enter the bloodstream, remaining in the body for months.

Forest fires

Brazil has a diverse range of environments and a large landmass, and its air pollution differs from that of other countries. Forest fires are a significant contributor to air pollution in Brazil. The country experiences a high number of wildfires, with an annual average of 1.4 million active fires between 2012 and 2017, representing about 7% of all active fires globally. These fires have severe consequences for air quality and public health, causing toxic air pollution and posing a significant health hazard.

The emissions from forest fires can travel great distances, affecting air quality far beyond the fire sites. The smoke from fires in the Amazon has been detected thousands of kilometres away, reaching the Andes and potentially contributing to the melting of Andean glaciers. The occurrence and extent of wildfires are increasing globally, and Brazil is no exception, with an area of 274,400 km2 burned in 2021, according to the National Institute for Spatial Research.

The health consequences of forest fire pollution are severe. Fine particulate matter (PM2.5) released by wildfires can penetrate deep into the lungs, leading to respiratory illnesses, lung cancer, and other health issues. Approximately 10% of premature deaths in Brazil due to PM2.5 are linked to smoke pollution from fires. Vulnerable communities, including rural populations living near the fires and those with limited access to healthcare, are at particular risk.

To mitigate the impacts of forest fires on air pollution and public health, policymakers should consider strategies related to forest protection, land use management, and agricultural practices. Improved cookstoves with chimneys, such as the Ecofagao and IDER, can help reduce indoor air pollution in households that rely on firewood or charcoal for cooking. Additionally, transitioning to less polluting fuels, such as propane (LPG), can significantly reduce pollution levels.

Fossil fuels

Brazil is the second-largest ethanol producer in the world, and ethanol is used as a fuel source for many vehicles in the country. While ethanol is a biofuel, its production and use have been linked to increased air pollution, particularly in terms of surface ozone (O3) concentrations. O3 has been associated with negative impacts on human health, damage to crops, and climate change. The state of São Paulo, a major ethanol producer, has seen increased air pollution from thermal power plants due to greater energy demand.

In addition to vehicular emissions, Brazil's air pollution is also attributed to a variety of factories that burn fossil fuels and release unique industrial effluence. Plastic recycling plants, for example, emit plastic fumes, while the burning of metals covered in lacquer or varnish releases volatile organic compounds. Poorly maintained construction sites further contribute to air pollution by releasing fine particulate matter, heavy metals, microplastics, and organic materials.

The impact of fossil fuel pollution on health is significant. Worldwide, air pollution from burning fossil fuels is responsible for about one in five deaths, or 8.7 million people in 2018 according to the Guardian. In Brazil, about 49,000 people die each year from air pollution, with half of these deaths attributed to outdoor pollution and the other half to household air pollution. Household air pollution is caused by cooking with wood and other solid fuels, primarily affecting rural communities.

Household air pollution

Brazil's air quality is generally considered moderate, with a PM2.5 reading of 15.77 μg/m³ in 2019. While this level of pollution is not overtly detrimental, it can still cause health issues for vulnerable groups, such as the young, the elderly, and those with respiratory issues or compromised immune systems.

Approximately 19 million Brazilians, or 9.5% of the population, primarily cook with firewood, and many others use wood as a secondary fuel. This results in the person cooking being exposed to dangerous levels of PM2.5, which can be up to 26 times the recommended level by the World Health Organization (WHO). The use of charcoal as a cooking fuel, while less polluting than wood, still contributes to substantial household air pollution.

To reduce household air pollution, improved cookstoves with chimneys that vent to the outside have been introduced. These stoves, such as the Ecofagao and IDER, burn about half the amount of wood as traditional stoves, reducing fuel costs and pollution levels. While transitioning to liquefied petroleum gas (LPG) stoves can be more expensive, it offers even greater health, fuel savings, and time benefits. Community-wide adoption of LPG stoves can lead to significant reductions in pollution levels.

Overall, addressing household air pollution in Brazil is crucial, as it not only saves lives but also provides economic and health benefits to the population.

Industrial emissions

Brazil's air quality is impacted by industrial emissions, with the country relying heavily on ethanol for fuel. This has led to increased surface ozone (O3) and nitrogen dioxide (NO2) levels, which are harmful to human health and the environment. The state of São Paulo, a hub for sugarcane production, is a significant contributor to these emissions.

The use of ethanol as a fuel source has doubled globally in the last two decades, and Brazil is the second-largest producer, with a 48.3% participation rate in the matrix of fuels used by Otto cycle engines. This high usage has resulted in rising O3 levels, which can be transported by wind to affect communities up to 200 km away. O3 precursors from the metropolitan area of São Paulo (MASP) have been detected in the city of Campinas, 90 km away, impacting its air quality.

Additionally, thermal power plants in Brazil have increased their emissions due to higher energy demands. Bagasse-fired power plants in the state of São Paulo contribute to around 25% of the state's energy production, emitting up to 27 Tg of CO2 annually. This is slightly higher than the emissions from plants burning fossil fuels, yet CO2 levels are rarely measured at air quality monitoring stations.

To address these issues, Brazil has implemented measures to reduce its dependence on fossil fuels and lower emissions. Curitiba, for example, has introduced innovative transportation solutions, including dedicated busways and extra-large buses, which have helped decrease fossil fuel consumption and air pollution levels. However, more action is needed to curb deforestation and subsequent fires in the Amazon, which release massive amounts of greenhouse gases and toxic pollutants, posing a significant threat to public health and the economy.

Frequently asked questions