巴西的空气质量

Does Brazil have polluted air?

Brazil is a country located in South America, officially known as the Federative Republic of Brazil. It is the largest country in south America, with approximately 211 million inhabitants, making it the 6^th most populous country in the world. It borders on a majority of the other countries located on the continent, having the largest economy in Latin America as well as an abundance of natural resources. As a country that is experiencing rapid growth and urbanization, along with the accompanying rural to urban migration occurring, Brazil is subject to some pollutive issues that come naturally with these changes.

Regarding its levels of pollution and air quality, Brazil came in over 2019 with a PM2.5 reading of 15.77 μg/m³, putting it into the ‘moderate’ pollution bracket, which requires a reading of anywhere between 12.1 to 35.4 μg/m³ to be classed as such. This means that Brazil came in on the lower end of this rating, making its air quality not overtly detrimental, but at the same time it may cause issues for those who are sensitive to chemical pollutants, as well as vulnerable demographics such as the young, the elderly and those with respiratory diseases or compromised immune systems.

This reading of 15.77 μg/m³ also put Brazil into 63^rd place out of all countries ranked worldwide, coming in just behind other countries such as Angola and Slovakia, which had PM2.5 readings of 15.90 μg/m³ and 16.10 μg/m³ respectively. PM2.5 refers to fine particulate matter that is 2.5 micrometers or less in diameter. With its incredibly small size, it has a whole host of negative effects on the health of anyone who respires it, and due to this it is used as a major component when calculating the overall air quality, or US AQI. There are also other factors involved in overall pollution levels, with larger particles such as PM10 (which whilst dangerous do not cause as much damage as their smaller counterparts) as well as chemical compounds such as ozone (O₃) and nitrogen dioxide (NO₂).

Brazil had many of its cities come in with good air quality ratings, with a large amount of them having several months of the year fall within the World Health Organizations target goal of 0 to 10 μg/m³, which is a very respectable quality of air. Even the most polluted city in Brazil (as of 2019), Campinas, saw a WHO target goal in the month of February, with an exact reading of 10 μg/m³.

However, a majority of the months of the year throughout all cities in Brazil came in with moderate rankings of pollution, showing the despite periods of very good air quality, there are some pollutive issues abound in the city, which will be discussed in short.

What are the main causes of pollution in Brazil?

With such significant landmass, and diversity of environments, the causes of pollution in Brazil are numerous as well as fairly unique in some regards, with the country as a whole relying a lot on ethanol for many of its fuel sources, and as such the pollutants and contaminants in the air differ from those of other countries, although there are still many similar causes of pollution that Brazil shares with the rest of the world.

One of these would be vehicular emissions and fumes, a major cause of pollution that is inescapable from round the world. With a fundamental lack of infrastructure catering towards public transport, as well as an abundance of low price (and low quality) fuels available, Brazil has tended towards a heavy reliance on vehicles, and as such much of its year-round ambient pollution levels would stem from the fumes and smoke emitted from automobiles, with many cars, motorbikes and heavy duty vehicles such as lorries, buses and trucks all inhabiting the roads, travelling the width of the country as well as across borders for reasons such as trade and travel (although this travel came to a significant halt in 2020 due to the outbreak of covid-19, with Brazil being heavily affected by it).

Many of these vehicles are of an older and more ancient variety, more prominently so in rural areas. Besides running on the aforementioned unique ethanol based fuels, other sources of vehicular pollution would come from ones that run on fossil fuels, particularly low quality diesel fuel, all of which give off their fair share of pollutants.

Other causes of pollution in the country include factories and industrial areas, many of which run on fossil fuels once again, such as coal. This in turn leads to high amounts of noxious smoke and haze entering the atmosphere, with many of these factories having little to no regulations on what their pollutive output is, although this is currently changing in more modern times with certain cities taking steps towards getting these issues under control, particularly when the fallout from it is observed (with heavy metals, burnt plastics and other sources of toxic pollutants causing birth defects and large scale damage to the environment being enough to attract the right attention that eventually brings an end to such practices).

The wide variety of factories, besides putting out pollution caused by the combustion of fossil fuels, all give off their own unique industrial effluence pertaining to whatever materials are being produced (for example plastic or metal recycling plants often give off plastic fumes, or volatile organic compounds that arise from the burning of metals covered in lacquer or varnish).

Lastly, other sources would include ones such as poorly maintained construction sites, that can give off large amounts of fine particulate matters as well as heavy metals and microplastics, and the burning of organic materials such as wood and other plant matter in rural or lower income areas for the purpose of cooking, heating, or clearing land for farming or other similar use.

Whilst manmade pollution issues taking the top spots, the occasional natural fire can occur that will cause PM2.5 levels to skyrocket in the particular area, as well as causing heavy pollutive issues for any cities nearby due to the effects of wind blowing pollution towards larger cities, whereby it gets trapped in the atmosphere.

When is pollution in Brazil at its worst?

Observing the data given over 2019 across the various cities, Brazil appears to have its worst pollution episodes towards the mid to end part of the year, with PM2.5 levels rising above what their normal numbers are for the rest of the year.

To use some cities as examples, the most polluted city in 2019, Campinas can once again be cited. Its highest pollution levels were observed in the mid portion of the year, with January through to April all being the cleanest before making a decline in air quality, with May through to August having the highest readings of pollution with recordings of 24.7 μg/m³ in May and 27.7 μg/m³ in June, making June the most polluted month of the year (whilst February was the cleanest).

To cite a city on the opposite end of the spectrum, Ribeirao came in as the cleanest city in 2019 with an average of 8.2 μg/m³, a reading that sits nicely within the WHO’s target goal. It too displayed its cleanest readings at the beginning and end of the year, with the mid to late months coming in with higher readings, with July through to September starting its decline with readings of 11.2 μg/m³, 10.7 μg/m³ and 15.7 μg/m³ all coming in respectively, making September the most polluted month for Ribeirao.

Of note is that due to Brazil's massive size, the diversity between pollution causes as well as geographical features and meteorological conditions, there are large differences between the cities, but as stated there does seem to be a distinct pattern of worser readings of pollution in the mid to late part of the year. Further examples are Sao Paulo, with its most polluted month coming in during July at 20.8 μg/m³, with another city such as Santos coming in with its worst reading in June at 22.9 μg/m³.

What are some of the main pollutants found in the air in Brazil?

With much of its pollution coming from sources such as vehicular emissions as well as smoke from factories, Brazil would have some pollutants that are fairly prominent in its atmosphere. They would include the aforementioned nitrogen dioxide, as well as sulfur dioxide (SO₂), both of which are found in higher quantities in areas that see larger volumes of cars and other automobiles. Nitrogen dioxide is particularly pertinent here, often correlating directly with heavy car usage, so much so to the point that its concentration in the atmosphere can be used to accurately detect how much pollution is coming from vehicle usage alone.

Some unique ones that would arise from the use of ethanol based products and fuels would be concentrations of acetaldehyde, vaporized forms of pure ethanol as well as nitrogen oxides. Others that arise from lower quality fuel use as well as the burning of organic materials would be carbon monoxide (CO), ozone (O₃) polynuclear aromatic hydrocarbons and fine particulate matter such as black carbon, which can arise from numerous sources including factory fumes, car smoke, open burn sites and construction areas. It is a major component of soot and is often found in blanketed on areas that see high volumes of traffic, in some cases mixing with other fine particles or chemicals emitted from car exhaust to create even more dangerous forms of PM2.5 or PM10.

Pollution released from forest fires, or the burning of wood or other forms of biomass can lead to the release of volatile organic compounds (VOC’s), some of which include formaldehyde, benzene, methylene chloride, toluene as well as xylene, all of which can have disastrous effects when inhaled over longer periods of time, as well as prominent short term issues involved. Of note is that VOC’s can be found within people’s homes, often emanating from household items such as recently painted surfaces, varnished woods, cosmetic products and other such similar materials, something to take into consideration for a cleaner home environment.

Is the air quality in Brazil improving?

Looking at the data taken over the last few years, it appears that there have been marginal improvements in the quality of Brazil's air. In 2018, Brazil came in with a PM2.5 reading of 16.29 μg/m³, which was then subsequently followed by the more recent reading of 15.77 μg/m³. Whilst this represents only a marginal gain, when it comes to matters of air pollution, any level of improvement can be seen a positive step in the right direction, particularly in recent years when air pollution has become a greater concern for many countries round the world.

What are some health issues associated with pollution in Brazil?

Whilst Brazil does not see catastrophic levels of pollution that are present in other countries such as Afghanistan or Bangladesh, which both had average PM2.5 readings of 58.80 μg/m³ and 83.30 μg/m³, as well as having certain months of their year come in with massive readings such as 181.8 μg/m³ in January in Bangladesh, it can be stated that any reading of PM2.5 that goes over the WHO’s target of 10 μg/m³ or less may present problems to human health, as well as the environment, with vegetation and animal ecosystems all being subject to greater dangers.

With readings as high as 47.6 μg/m³ coming in during August in Rio Branco, as well as other cities having numbers of PM2.5 going up to 27.7 μg/m³ in Campinas, the health effects that may follow would be raised instances of cancer, particularly that of the lungs but also of the throat, stomach, skin and blood.

With fine particulate matter in the air, scarring and rapid aging of the lungs can occur, which can not only reduce the lungs full capacity to take in oxygen, but can also cause further instances of respiratory conditions such as bronchitis, pneumonia, aggravated asthma attacks and emphysema to occur. Other conditions would include ischemic heart disease, caused by a lack of oxygen to the heart tissues, as well as other cardiac events such as heart attacks and arrythmias.

Expectant mothers may find themselves at risks of having a miscarriage, or their child being born prematurely with a low birth weight, bring up the overall mortality rate related to pollution as well as causing possible lifelong cognitive and physical defects to the younger generation, as well as any of those exposed to areas high in smoke, haze, plastic or industrial fumes as well as the many different dangerous materials being burnt.