Buses and trucks represent only 5% of the total fleet of 7 million vehicles circulating in the streets of São Paulo, but they are responsible for almost half of the total pollution registered in the city. This conclusion comes from a study produced by the Institute of Physics of the University of São Paulo and published in the Scientific Reports magazine, Nature group.
These heavy vehicles are responsible for emitting approximately 30% of the carbon monoxide (CO), which corresponds to 40% and 45% from benzene and toluene emissions, and 50% from “black carbon” (which is an impure type of gas emitted by the incomplete combustion of fossil fuels) production.
The survey was conducted in downtown São Paulo during the three months of spring season, when traditionally, it rains more and is less polluted – the data were collected in 2013. It used the measure of the ethanol amount in the atmosphere to differentiate the pollution emitted from light vehicles exhaust (cars and motorcycles) from the pollution produced by heavy vehicles.
"From the results obtained, the reduction in the use of vehicles in the city, combined with the expansion of subway lines, for example, is the first and most effective method to mitigate pollution in São Paulo. A great cost-benefit can also be obtained by reducing pollutant emissions by buses," explains Professor Paulo Artaxo, lead author of the academic article.
Artaxo says the filters used in Europe eliminate 95% of emissions from diesel vehicles, including buses: "It is very important that these new technologies, which are not expensive and can be adopted in the short term, are effectively implemented in São Paulo and in large Brazilian cities."
There are 100 passenger vehicles for each bus and 30 for each truck in the metropolitan region of São Paulo. According to the study, from the analyzed particles, 45% were emitted by passenger cars that burned gasoline while 55% came from the cars that burned ethanol.
Pollution is one of the major causes of death in the world
Pollution resulting from human-induced environmental impacts annually kills 9 million people worldwide, i.e. 16% of all deaths registered each year. It is still expensive: the side effects of pollution bring losses of US$ 4.6 trillion per year or approximately 6% of the world's economy and almost three times the Brazilian GDP in 2017.
These numbers are the conclusion of the work performed by the Global Alliance on Health and Pollution (GAHP). The study also resulted in the Pollution.org interactive map, which gathers information on air, water, and soil contamination, as well as on pollution-related deaths.
As for Brazil, there are 489 deaths due to pollution for every 1 million inhabitants, a rate close to the rates of the USA (483), Mexico (410) and much lower than the rates of European countries such as Germany (764) and the Netherlands (726). Brunei, in Southeast Asia, has the best performance (95) and Somalia, in Northeast Africa, is the nation most affected by pollution (3,261).
According to the annual report of the World Health Organization (WHO), 92% of the world's population live in environments where air quality does not meet the targets set by the organization. This most aggressively affects low-income countries: 92% of pollution-related deaths are in said countries, and related diseases jeopardize even more their economies.
Hope for a more sustainable future
If the current picture looks heartbreaking, there is real hope for a more sustainable future. The GAHP report shows that investing in environmentally correct actions, in addition to the obvious direct environmental and human health outcomes, is also highly profitable.
The document states that countries that have made environmental commitments and made progress in this regard have also seen almost 250% growth in their GDP. "The assertion that pollution control stifles economic growth and that poor countries must go through a phase of pollution to achieve development has been proved a mistake," concludes the paper.
The publication mentions the example of the United States.
Over there, for every dollar invested in fighting the pollution since 1970, there is a return of US$ 30 to the country's economy. Considering that investments made in this sense, today, amount to US$ 65 billion, the total return on such investments is approximately US$ 1.5 trillion.
The account takes into consideration the amount the government did not need to spend on pollution-related illnesses and the increased cognitive function of children and young people, which positively impact on productivity and the national economy.